Guy Holt

That about sums it up, and I haven’t even got into half of it. For example, Massachusetts now requires GFCIs on outdoor set lighting of 150 V or less, and 50 A or less (Section 210.8 (B)(4)). Whereas the City of Los Angeles, where much production takes place, exempts outdoor sets from the requirement for ground-fault protection with GFCIs. How two AHJs, on opposite sides of the country, can come to opposing positions says a lot about the nature of the Code. Let’s explore how it came to this, its ramifications for the distribution of power on set, and what we can do about it. The benefit of using GFCIs is indisputable. According to research done by the National Electrical Manufacturers Association, household electrocutions have fallen in proportion to the number of GFCIs being used from 1976 to 2001. So, it was inevitable that during the 2020 Code review cycle, there would be a general agreement among Code panel members that GFCIs should be used more widely. A spate of electrocution accidents—a child in Oklahoma retrieving a pet from behind a clothes dryer, a 10-year-old Houston boy playing hide-and-seek, a 12-year-old in Chicago being electrocuted when he touched an AC condenser unit with an electrical fault—sealed the deal resulting in the 2020 Code setting a higher standard across more areas of the Code. For instance, Section 210.8(B)(4) now requires GFCI protection for all outdoor outlets supplied by branch circuits rated 150 V to ground or less, 50 A or less. This update extends the GFCI requirement to include all fixed or portable power connections outdoors—even hard-wired equipment outdoors, like AC compressors. Since there are no readily available dimmer rated Class A GFCIs, Code Panel 15 (which includes mainly LA entertainment industry representatives), sought and was granted an exemption to Section 210.8 in Article 530, motion Picture and television Studios and Similar Locations. This exemption would be good news for us if not for the fact that Article 530, is widely interpreted by AHJs outside California to mean that it does not pertain to location filming. Section 530.2 defines a “Motion Picture Studio” as: “A building or group of buildings and other structures designed, constructed, or permanently altered for use by the entertainment industry for the purpose of motion picture or television production.” And a “Shooting Location” as: “A place outside a motion picture studio where a production or part of it is filmed or recorded.” So, by definition they are not the same occupancy. Many AHJs take this to mean that the exemption to Section 210.8 permitted by Article 530 does not extend outside the confines of a stage. LA County, by comparison, extends the Article 530 exemption to include location filming outdoors. that’s because the AHJs in California interpret the intent of the Code so that obtaining a location permit temporarily changes the occupancy of a location to a “motion picture studio.” This simple provision accommodates a local industry while keeping the Code in force generally. Why not grant the LA film industry an exemption? With an average annual rainfall of only 14", the likelihood of receiving a lethal electrical shock while working outdoors is much lower in Los Angeles than it is in Massachusetts where the average annual rainfall is three times greater (43"). This is just one example, of many across the country, of an AHJ modifying the code to suit the needs of a local industry. So, despite its authoritative position and having “National” in its title, NEC standards are merely a template local governments use to create and enforce their own electrical code that meets their own needs. This leaves us here in Massachusetts with a problem: Section 210.8(4)(B)) applies to outdoor location filming—not only to craftie and video-village, but also to small cord set lighting as well. Unless the Code is revised, our dilemma will eventually become your dilemma as the 2020 Code is adopted by more states and municipalities across the country. Aware of the potential downside for motion picture production across the country, an industry trade group has formed to advise Code Panel 15 to make explicit in the 2023 Code that Article 530 exemptions extend to production on location as well as in the studio, but until then we are stuck with this Article 210 requirement to use GFCIs on small cords outdoors. This presents set lighting technicians with a challenge: the readily available inline GFCI dongles you get at hardware stores are prone to nuisance tripping with motion picture lighting loads and are only rated for 15 A, not 20 A. The residual currents generated by the electronic power supplies used in HMIs, fluorescent luminaires, and now LEDs sensitize these GFCIs so that they are very susceptible to tripping. To improve the generally poor reliability of GFCIs, in 2003 UL published a new standard for GFCIs (UL 943) designed to prevent nuisance tripping by transient conditions that are not of a sufficient duration to pose a hazard. The new standard allows GFCIs to trip on an “Inverse Time Curve.” An inverse time curve introduces a delay that decreases as the magnitude of the current increases. The delay allows transient conditions that do not pose a hazard to pass without tripping the GFCI. UL 943 also permits GFCIs to filter high-frequency currents to eliminate residual currents and thereby further reduce nuisance tripping. Even though the UL 943 standard was meant to enable GFCIs to operate more reliably in real world conditions, manufacturers of inexpensive Class A GFCIs, like those found in hardware stores, do not implement the UL 943 curve because it requires sophisticated micro-processors, which makes the GFCI much more expensive. For the same reason, they do not filter high-frequency residual currents. They use a more aggressive response than required by UL 943 (typically 250 ms at 6 mA where UL 943 permits 5.59 seconds). This more aggressive trip curve and lack of filtration does not generally pose a problem in the one-tool per circuit applications for which hardware store GFCIs are designed. However, the more aggressive trip curve of this style of GFCI has proven to be a problem in applications involving non-linear lighting loads, (the lights increasingly being used in motion picture production and event staging.) So, what’s a set electrician to do? Fortunately, NEC Section 215.9, Ground-Fault Circuit-Interrupter Protection for Personnel provides general permission for a feeder to be GFCI protected where it supplies 15 A and 20 A branch circuits requiring GFCI protection under Section 210.8. the section reads as follows: “Feeders supplying 15- and 20-ampere receptacle branch circuits shall be permitted to be protected by a ground-fault circuit interrupter in lieu of the provisions for such interrupters as specified in 210.8 and 590.6(A).” Since this section prescriptively identifies feeder GFCI protection “in lieu of,” it permits the use of “film style” GFCIs with 100 A Lunch Boxes to satisfy the expanded Section 210.8 requirement for GFCI protection on all branch circuits rated 150 V to ground or less, 50 A or less. This is good news for us. Film style GFCIs, like the Lifeguard, Shock Block, or Shock Stop are a lot less prone to nuisance tripping because they employ high-frequency filters and a trip curve that more closely approximates the inverse-time curve of UL 943. (use this link for more detailed information on the benefits to using film-style GFCIs on set). So, given the variety of code interpretations, it is important to always check with the local AHJ for regional differences from the national Code. Guy Holt, Gaffer, ScreenLight & Grip, Lighting rentals and sales in Boston

A few questions: 1) If I understand your OP correctly, you did this in your sister's cafe to power one of her coffee makers and now are asking hypothetically if it can be done to power a 4-6kw HMI. Is that correct? 2) What size two pole breaker did you put in the panel for the coffee maker? What size two pole breaker would you put in the panel to power a 6k. 3) When combining the two 20A receptacles in your sister's cafe to a single 220V receptacle, what did you do with the two neutrals and two ground wires of the original receptacles? Did you wire just one or both neutrals to the single 220V receptacle? Would you have to wire the two neutrals and two ground wires of the original receptacles to the L14-30 receptacle you are installing to power a 4-6kw HMI? If yes, why? If no, why not? 4) The Bates plug on the ballast of a 6kw has three conductors. An L14-30 receptacle has four conductors. Would you drop a conductor? If so, which one? Would you combine two conductors? If so, which two? 5) Did you use a live wire circuit tracer when rewiring your sister's receptacle? Would the use of a live wire circuit tracer be required when rewiring a receptacle for a 4-6k HMI? 6) Was there a source of water within 6' of the receptacles in your sister's cafe? What if the receptacle you rewire for a 4-6kw is within 6' of a water source? 7) Did your sister's cafe have a single phase or three phase service? Would it make a difference if the service was single phase or three phase in doing what you propose to power a 4-6k? 8) Would it make a difference if the 4-6k HMI ballast was power factor corrected or not? Please respond to each of these questions in detail. Thanks, Guy Holt, Gaffer, ScreenLight & Grip, Lighting equipment rental and sales in Boston.

I agree that job protection is written into the Code, but not the type you think. NEC Section 530.6 is, to my mind, one of the most important code articles because it creates our job. Without that single article, what we do would likely be the jurisdiction of some International Brotherhood of Electrical Workers (IBEW) Local and require a state license. But, unfortunately, the NEC is not the final word on this issue. Despite its authoritative position and national title, NEC standards are merely a template local government uses to create and enforce their own electric code. Since the NEC provides the minimum requirements for electrical safety it is fairly common for jurisdictions to have local codes or amendments that modify or supplement the minimum rules in the NEC. These are generally of a nature that makes the rules more restrictive and are usually necessary due to unique or adverse conditions within a particular jurisdiction. For example, even though Article 530’s definition of a “Qualified Person” does not require a state license, the Massachusetts Board of State Examiners did not adopt it without change. The Examiners, according to the state website “assist local wiring inspectors in mediating code disputes between licensees and wiring Inspectors.“ In a code dispute in 2003, the Examiners added their own requirement, based upon Massachusetts General Laws, that Qualified Persons must operate under the supervision of a licensed electrician. The history of how we got here is worth exploring in detail because it is indicative of the significance of the Code to local authorities and goes something like this: In 1948, in Maria v. State Examiners, (362.Mass.551,552-555 (1974)) the Board of Examiners petitioned the Attorney General of Massachusetts to rule whether the wires and apparatus used in television installations (CamLok and Bates connections) constituted the use of “electricity for light, heat, or power purposes”, which under Massachusetts General Law requires a license. The Attorney General ruled that it did not require a license. In doing so, he affirmed the role of a Qualified Person as envisioned by the Code. Fifty-five years later, a Boston Inspector of Wires cited a production company for a Code violation because their crew were connecting and disconnecting CamLok and Bates style equipment without having a company license. The production company appealed the violation to the Board of State Examiners. Citing Massachusetts General Laws Chapter 141 section 8, the Examiners ruled in a Private Letter Ruling, dated July 31, 2003, in favor of the production company over the Inspector with the caveat that “the company regularly employs electricians ...[and] such work is required to be supervised by a person licensed under this Chapter” (the underscore is mine). And, in the next paragraph, citing Massachusetts General Laws Chapter 143 section 3-L, the Examiners asserted their right, as a “matter of consumer protection”, to inspect all electrical wiring and equipment used in filming motion pictures. Including, portable and vehicle-mounted generators and portable electrical distribution systems; additions or alterations to premises wiring systems, permanent electrical infrastructure, or other fixed wiring systems regardless if it will be dismantled, abandoned, or removed at the conclusion of filming. Where it requires a license in the state of Massachusetts to pull a permit and schedule an inspection, in their ruling the Examiners effectively subjugated Qualified Persons to licensed electricians even though the Attorney General of Massachusetts had previously affirmed the role of a Qualified Person as envisioned by the Code. So, despite its authoritative position and national title, NEC standards are merely a template that local governments use to create and enforce their own electric code. So where does that leave you? Having to navigate a patchwork of code permutations across the country. Given the variety of code interpretations, it is important to always check with the local Authority Having Jurisdiction (AHJ) for regional differences from the national code. Depending on where the work is taking place the AHJ may be the local city electrical inspector, the fire marshal (also known as a Film Safety Officer), or the studio’s safety officer. Guy Holt, Gaffer, ScreenLight & Grip, Lighting rentals and sales in Boston

While that is true, paid professionals are more likely to use equipment that warrants safety training than do unpaid amateurs. NEC Article 520 makes a similar distinction between what is and is not safe for an amateur to use – just in a different way. Section 520.53(P) permits an untrained person to use only listed plug and cord connected distribution systems of less than 150A. The operative words being “listed“ and “plug and cord connected.” A listed plug and cord connected system is a turnkey system whose components are compatible by design, equipped with over current protection sized to connected conductors, and tested to a UL standard. Where there are no exposed live parts and connections are designed to make the Equipment Grounding Conductor first and break it last, listed plug and cord connected systems are extremely safe and almost dummy proof and therefore suitable for unpaid amateurs. Professional productions that pay their employees are more likely to use such things as feeder taps, single-conductor (CamLok) feeders that can be connected in the wrong order, and over-size breakers by 400%, and so require the services of a trained qualified person. The Code article pertaining to motion picture studios, NEC Article 530, does not make an exception for listed plug and cord connected systems of less than 150A, but instead draws the line at whether the production is using a professional format or not (Section 530.1 Scope.) Productions using a professional format are more likely to pay employees and use such things as feeder taps, single-conductor (CamLok) feeders that can be connected in the wrong order, and over-size breakers by 400%, and so require the services of a trained qualified person. Productions using amateur formats are more likely not to pay their crew and use only listed plug and cord connected equipment (a listed extension cord plugged into a listed wall receptacle backed up by listed overcurrent protection.) Since listed plug and cord connected systems are extremely safe and almost dummy proof, they are suitable for unpaid amateurs. The bottom line is that if you pay someone to plug-in a light, you enter into an employer/employee relationship with that individual. According to the U.S. Occupational Safety and Health Administration (OSHA) you are therefore responsible for their safety and for providing the safety training required by NEC Article 530. If you are not prepared to provide that training to your crew, your best recourse is to hire a union crew and contribute to the union's training fund. Guy Holt, Gaffer, ScreenLight & Grip, Lighting rentals and sales in Boston

Clearly Article 530 hasn’t been updated in a while. In fact, there is a proposed update making its way through the approval process that will be part of the 2023 edition of the NEC. The intent of Section 530.1 then as now is to distinguish between professional and amateur productions and align Article 530 with Occupational Safety and Health Administration (OSHA) CFR Regulations. After all what distinguishes professionals from amateurs is that professionals get paid. Paid by whom? By their employer. According to OSHA regulations the employer is responsible for worker safety and providing safety training, which is why it is the studios that fund the Safety Pass Program and why producers pay $1 into my local’s training fund for every day I work under a union contract. Since it is not practical for producers to provide safety training for each project, they meet this OSHA and NEC requirement by funding such training by the unions. The NEC and OSHA definitions of a qualified person differ slightly. OSHA regulations contain a bit more criteria for qualified people. OSHA CFR Regulation 1910 defines a “qualified person” as “one with a recognized degree or professional certificate and extensive knowledge and experience in the subject field who is capable of design, analysis, evaluation, and specifications in the subject work, project, 
or product.” OSHA CFR Regulation 1926 defines it as “one who, by possession of a recognized degree, certificate, or professional standing, or who by extensive knowledge, training, and experience, has successfully demonstrated his ability to solve or resolve problems relating to the subject matter, the work, or the project.”
 These two definitions differ in that, for general industry purposes, OSHA defines the term as someone who has both a certification and industry experience. The construction regulation contains a bit more criteria for qualified people, including a recognized degree, certificate or professional standing, or who, by extensive knowledge, training and experience, has successfully demonstrated related abilities. The key difference is “demonstrated abilities” related to the project or work. These definitions provide the basis for the more specific definitions of qualified people contained in the NEC and NFPA 70E. Since workers can be qualified in one area and unqualified for another, in both regulations it is the responsibility of the employer to assign qualified people to perform tasks and operations requiring specific knowledge and skill sets. Even though the employer is ultimately responsible and therefore liable in the event of an accident, employees have a responsibility to know the limits of their qualifications and to admit when they are not qualified to perform a particular task or function. Which makes it necessary for a qualified person to not only have experience, knowledge, skills, and safety training, but also have an understanding of the limits of their own qualifications. Guy Holt, Gaffer, ScreenLight & Grip, Lighting rentals and sales in Boston

In my opinion, the two best introductory books for set electricians are The Set Lighting Technician’s Handbook by Harry Box and Electricity for the Entertainment Electrician and Technician by Richard Cadena (an ETCP certified trainer.) For more advanced reading on the use of power in motion picture production I recommend a series of articles I have written for Protocol (the quarterly journal of ESTA.) Guy Holt, Gaffer, ScreenLight & Grip, Lighting rentals and sales in Boston

No. In the codes and standards world, language is used very precisely. The qualified person requirement of NEC Section 530.6: Portable Equipment pertains to the use of “Portable stage and studio lighting equipment and portable power distribution equipment” outdoors, not someone plugging in a laptop in the production office or hair and make-up plugging in a hair dryer. And as it states in its beginning, Section 530.1 Scope: “The requirements of this article shall apply to television studios and motion picture studios using either film or electronic cameras, except as provided in 520.1, and exchanges, factories, laboratories, stages, or a portion of the building in which film or tape more than 22mm in width is exposed, developed, printed, cut, edited, rewound, repaired, or stored.” So clearly Article 530 applies to business ventures in film, not to an amateur making a film of the local high school play. Guy Holt, Gaffer, ScreenLight & Grip, Lighting rentals and sales in Boston

As we all know producers would squeeze Lincoln off a penny if they could, so they cut corners where-ever they can, including when it comes to worker safety. As Phil suggested in his OP, let’s litigate this issue as it would be in a court of law. Every province, state, or municipality has a body of law that pertains to this question and it has nothing to do with common sense. I highly recommend that anyone handling or energizing lighting equipment familiarize themselves with their local laws. That being the case, it is simply wrong to say: “General Liability Insurance here doesn't require a set electrician.” Insurance regulations are based on prevailing law. If you fail to follow the law, your insurance is null and void. Insurance does not provide blanket protection against breaking the law. In the US local laws are based on the National Electrical Code (NEC), which a state or municipality adopts in its entirety or modifies when adopting it into law. From a regulatory standpoint, the dichotomy Phil sets up in his original question (set electrician vs. non-set electrician) is a false one because the classification “set electrician” has no meaning in the NEC. Regulating agencies in the US identify three classes of worker: licensed, unlicensed trained workers (qualified personnel), and untrained workers. It is important to understand the difference between each class of worker and what they are permitted to do under the law. The prevailing Code article for what we do is NEC Article 530, Motion Picture and Television Studios and Similar Locations. In the 2017 edition of the Code (the edition adopted by most states) Section 530.6: Portable Equipment states: “Portable stage and studio lighting equipment and portable power distribution equipment shall be permitted for temporary use outdoors if the equipment is supervised by qualified personnel while energized and barriered from the general public.” While the term “qualified person” has a very broad meaning in a general context, in the codes and standards world, what constitutes a qualified person in the context used within contained requirements is very specific. The NEC Section 100 definition of a qualified person is “One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved.” As used in the NEC, the term “qualified person” primarily relates to the ability to understand the equipment and installations covered by the code and how to attain compliance with NEC safety rules when performing installations. It is important to note that in this definition the NEC does not indicate who performs the work (i.e. a licensed electrician or not). It also does not regulate a person’s qualifications or credentials in the craft. 
That’s because when it comes to codes and standards, local regulatory agencies establish the requirements for industry licenses or certification. NEC Article 530 simply requires that an individual using portable stage and studio lighting equipment and portable power distribution equipment know how to comply with NEC safety rules when performing installations. Most states have strict electrical licensing and electrical inspection requirements. In general, qualified persons are only allowed to connect or inter-connect multi-conductor cords and single-conductor cables that are equipped with approved separable multi-pole connectors (Twist-Lock or Bates) or single-pole connectors (CamLoks). Licensed employees of licensed electrical contractors are required to connect or terminate cords and cables that have bare ends, clamps, clips or other types of connections other than the approved separable connectors mentioned above. Licensed employees of licensed electrical contractors are also required to perform all electrical work on interior or exterior premises wiring systems or any other fixed electrical infrastructure, regardless if it will be dismantled, abandoned, or removed at the conclusion of filming. Technically, that includes the use of zip cord and add-a-taps to energize practical fixtures. NEC Article 520: Theaters and Similar Locations goes one step further by noting an exception to this general rule. In Section 520.53 Supply Conductors, (P) Qualified Person the Code states: "The routing of portable supply conductors, the making and breaking of supply connectors and other supply connections, and the energization and de- energization of supply services shall be performed by qualified personnel ....” But then allows the following exception: “A portable switchboard (distro) shall be permitted to be connected to a permanently installed supply receptacle by other than qualified personnel provided that the supply receptacle is protected for its current rating by an overcurrent device of not greater than 150 amperes, and where the receptacle, interconnection, and switchboard comply with all the following: (a) They employ listed multiple connectors suitable for the purpose for every supply interconnection (b) They prevent access to all supply connections by the general public (c) They employ listed extra-hard usage multiconductor cords or cables with an ampacity not less than the load and not less than the ampere rating of the connectors The intent of this 520.53(P) exemption is to separate what are acceptable practices in professional theatre venues from those in amateur theatre or educational venues. The basic requirement of 520.53(P) allows for such things as single-conductor (CamLok) feeder systems, feeder taps, and the over-sizing of breakers by 400% if feeders are sized for the current-connected load, and so require the services of a trained qualified person. The exception to 520.53(P) permits an untrained person to use only listed plug and cord connected distribution systems of less than 150A. It is important to note, that the Code article pertaining to motion picture studios, NEC Article 530, does not make an exception for listed distribution systems of less than 150A suitable for use by an untrained person. All portable power distribution equipment, regardless of its rated ampacity, is to be handled only by trained qualified personnel. It is also important to note that the qualified personnel requirement of Section 530.6: Portable Equipment pertains to “portable stage and studio lighting equipment” as well as “portable power distribution equipment”, which means, the fact that you are plugging lights into house receptacles does not exempt you from the Code requirement that you know how to comply with NEC safety rules. This becomes abundantly clear when you consider the new Section 210.8(B)(4) requirement for GFCI protection on all outdoor receptacles of 125V or less to ground, 50 amperes or less. This Code requirement applies regardless whether you are distributing power from a generator or running a stinger out a window to power a light. If the receptacle is outdoors, it requires a GFCI by Code regardless whether it is permanent or portable. Ignorance of this Code requirement is not an acceptable excuse for violating the law. In other words, regardless whether it is a union or non-union job, whether the light is plugged into a wall outlet or into a portable power distribution system, NEC Article 530 requires that the individual handling the light ”has received safety training to recognize and avoid the hazards involved.” This fundamental Code requirement was brought home to me when I was tangentially involved in a workplace accident. The insurance adjuster was interested in knowing only one thing, had I received the safety training required under the law. The reason big budget studio productions use union crews is not because they are better (there are some very good non-union crews), but because the unions provide their members the safety training required by law that protects the studios from liability (which is the purpose of the Safety Pass program administered by the Contract Services Administration. Use this link for details.) Of course, the safety training received by union crews also makes them better. For example, not only are union crews trained when to use GFCIs, but also what GFCIs to use to minimize nuisance tripping in electrically noisy environments like movie sets (those manufactured by LifeGuard, Shock Block, and Shock Stop) (Use this link for more details.) So, to answer Phil’s question as it pertains to film production in the US, any work that occurs in the special occupancy of a motion picture production (regardless whether it is a big budget studio feature, commercial, or low budget indie) by law must be performed by an individual who has received formal training on how to comply with NEC safety rules when performing installations. For those non-union set electricians who want to protect their employers from liability by receiving recognized safety training, the Entertainment Services and Technology Association (ESTA) offers the Entertainment Technician’s Certification Program (ETCP) for Portable Power Distribution Technicians (PPDT). A rigorous four-hour exam administered by independent local testing agencies, the ETCP PPDT exam covers a broad range of topics including NFPA 70E, the standard for electrical safety in the workplace recognized by the NEC. Passing this exam demonstrates that an individual has the appropriate knowledge and skillset to distribute power and has received safety training to identify and avoid electrical hazards (use this link for details.) Guy Holt, Gaffer, ScreenLight & Grip, Lighting rentals and sales in Boston

Not being familiar with the Yongnuo YN1200W LEDs I can’t speak specifically regarding that light, but I can speak to lights with electronic power supplies in general. With light sources that use Switch Mode Power Supplies (HMIs, Fluorescents, & LEDs) it matters not only what type of generator you use but also what type of power supplies the lights use. The poor power factor and harmonic noise that non-power factor corrected Switch Mode Power Supplies (SMPS) draw can have a severe adverse effect on the power waveform of conventional generators, but not inverter generators. Under the best of circumstances a 4kw HMI will only draw 38 Amps and you will have no problem operating them on a 6500W portable generator. Under the worst of circumstances a 4kw HMI will draw 52 Amps and you will have nothing but trouble operating them on the generator. Why the difference? Because it depends on whether the HMI ballast is power factor corrected (PFC) and whether the generator is an inverter generator or a conventional AVR generator. The poor power factor (PF) of lights that use Switch Mode Power Supplies (Electronic HMI, Fluorescent, & LEDs) can cause them to use excessive amounts of power for the wattage of light they generate and draw harmonic currents that can have a severe adverse effect on not only the generator, but also other electronic equipment operating on the same power. Since PFC is not mandatory in this country as it is in Europe, you will encounter many non-PFC HMI, Kino, & LED power supplies. And, since the adverse effects caused by a poor power factor (PF) go beyond an inefficient use of power, it is well worth understanding power factor. To understand PF lets first compare the PF of a CFL bulb, and its’ effect on the power supply, to that of an incandescent bulb. While not as sophisticated as an expensive 4kw HMI ballast, the ballasts of CFLs operate on the same basic principle. The AC power supply is first converted to DC by a diode-capacitor circuit and then back to AC by a switch mode converter. The only difference between an HMI ballast and a CFL is the type of AC power waveform the switch mode converter generates. An electronic HMI ballast generates a 60/75Hz square wave, while a CFL generates a high frequency sine wave. In contrast, an incandescent light is a simple resistive load. The high resistance of its tungsten filament creates heat until the filament glows - creating light. As we see in the oscilloscope shot below of a 25W incandescent bulb, the current is always proportional to the voltage (current is represented on the scope as the voltage drop on a 1 Ohm resistor.) http://www.screenlightandgrip.com/images/generators/Incan_Waveform.jpeg If the applied voltage is sinusoidal, the current generated is also sinusoidal. That is, the current increases proportionately as the voltage increases and decreases proportionately as the voltage decreases. Since the peak of the voltage corresponds to the peak in current, the voltage and current are also in phase and so have a unity PF (PF of 1.) The voltage and current waveforms below of a CFL bulb are very different from that of the incandescent light above and also representative of that drawn by non-PFC LED power supplies. The most noticeable difference is that the current, generated by the CFL bulb, no longer proportionately follows the nice smooth sinusoidal voltage waveform supplied to it. Rather, it has been distorted by electrical components in the ballast of the CFL bulb so that it instead consists of high amplitude sharp spikes in current that quickly drop off. Also, the peak of the voltage no longer corresponds to the peak in current. The current now “leads” the voltage by 1.7 micro seconds. The voltage and current are no longer in phase as in the case of an incandescent bulb, but instead exhibits what is called a “Leading Power Factor.” Typical PF of a CFL .55. (the lower the number the worse the PF.) http://www.screenlightandgrip.com/images/generators/CFL_Waveform.jpg The distorted current waveform and leading PF exhibited here are also characteristic of LEDs because they operate on similar principles. When it converts the AC supply to DC, LED power supplies likewise use only a portion of the voltage waveform, draws current in high amplitude quick bursts, rich in harmonic currents that stack on top of one another, creating harmonic distortion similar to the CFL. As such, LED power supplies draw more power than it uses to create light. One would think that only the less expensive LED lights would not be power factor corrected (PFC), but that is not the case. In a random sampling of lights that I did for one of my articles, the power factor of expensive name brand fixtures ranged from .45 to .63 with total harmonic distortions ranging from 75-85%. Even those that were power factor corrected generated harmonic currents when dimmed. For instance, the PF of the Litepanel Astra 1x1 dropped from .99 to .54 when dimmed 50% (THD increased to 83.2%.) To see the results of my tests use this link. There is a video on You-Tube by a Lighting Designer by the name of Kevan Shaw that illustrates the effect that lights with a poor PF can have on conventional generators. In his You-Tube Video, “Compact Fluorescent versus the generator,” (available at http://www.youtube.com/watch?v=LeCqreRMzKM) Kevan Shaw compares the effect of equal wattages of CFLs and Incandescent lights on a small portable generator. In his test he first operates a 575W ETC Source Four Leko with Quartz Halogen bulb on an 850W two stroke conventional gas generator without problem. However, when he tries to operate an equivalent wattage of CFLs (30-18W bulbs) the generator goes berserk. Only after turning off half the CFL Bulbs does the generator operate normally with a remaining load of 15 - 18W CFLs (270 W.) What accounts for the erratic behavior of the generator in this video under a smaller load of CFLs? It is a combination of the poor PF of the CFL bulbs and the harmonic currents they generate. Even though the 15 CFL bulbs have a True Power of 270W (15 x 18W = 270W ), the Watt indicator on Kevan's generator indicates that they draw twice that in Apparent Power (535W), or have a Power Factor of .5 (270W/535W =.504.) The fact that CFL bulbs consume double the energy (Apparent Power) for the 18 Watts of light (True Power) they generate, is only half the story here. Kevan Shaw’s video also clearly demonstrates the severe effect that poor power PF loads - like non-PFC CFLs, HMIs, & LEDs - can have on the governing systems of conventional AVR generators. When Kevan turns off the 18W CFL bulbs one at a time until the generator stabilizes, he is not only demonstrating that 15 – 18W CFL bulbs has roughly the same Apparent Power (535W), according to the generator’s Watt meter, as a 575W incandescent light; but, also that the maximum Leading Power Factor load a 850W conventional generator can operate satisfactorily is 270 Watts (15 – 18W CFL bulbs). Looked at from another angle, 576 Watts of Apparent Power with a Leading Power Factor (16 - 18W CFL bulbs) overloaded the generator, while 575 Watts of Apparent Power with a Unity Power Factor (the 575W Quartz Leko) did not. What accounts for this difference? Since the load is almost the same (576 & 575 Watts of Apparent Power respectively), the only factor that can account for the generator going berserk with the equivalent load of CFL lights is the harmonic currents that they generate, that the Quartz Leko does not. Without a doubt, Kevan Shaw’s video is a clear demonstration of the adverse effect that harmonic currents have on the governing systems of conventional AVR generators. But that is not all. An even closer analysis of the video also shows that the voltage waveform distortion created by the harmonic currents also affects electronic equipment operating on it. For instance, after turning off 18W CFL bulbs until the generator stabilized, Kevan still does "not get.. all the lamps to illuminate properly." What accounts for the bulbs not illuminating properly even though the generator has stabilized? While the Harmonic Distortion generated by the remaining CFLs is not sufficient to affect the generator governor, it is clearly affecting the CFLs themselves - an indication that, short of affecting the generator's governing system, the voltage waveform distortion generated by harmonic currents will adversely affect electronic equipment operating on the distorted power (use this link for more details.) The adverse effects of the harmonic currents that non PFC power supplies generate, so graphically demonstrated in Kevan’s video, limits the total amount of Leading Power Factor loads (non-PFC HMIs, Kinos, & LEDs), as compared to Unity Power Factor loads (Tungsten), that can be reliably operated on conventional AVR generators. For this reason, the conventional wisdom in the past has been to not load the generator beyond 50% when using a lighting package with low PF (non-pfc HMIs, Kinos, & LEDs). By de-rating the load capacity in this fashion, a Gaffer minimizes the adverse effects of high Harmonic Distortion so that both the generator and the loads placed upon it operate more reliably. However, this conventional wisdom no longer holds true if the ballasts are power factor corrected (PFC) and powered by an inverter generator. http://www.screenlightandgrip.com/images/generators/wwaveform_pkg_comp_AVR_In.jpg Left: Conventional generator power w/ pkg. of non-PFC Elec. HMI Ballasts & Kino Flo Wall-o-Lite. Right: Inverter generator power w/ Pkg. of PFC Elec. Ballasts & Kino Flo Parabeam 400. For example, the severely distorted power waveform above on the left is caused by a 2500W load (consisting of non-PFC HMI Ballasts & a non-PFC Kino Flo Wall-o-Lite) operating on a conventional Honda EX5500. The nearly perfect waveform on the right is the same 2500W load but with PFC operating on our modified Honda EU6500is Inverter Generator. As you can see, the difference between the resulting waveforms is startling. Even though the load is the same (2500W), the fact that it is Power Factor Corrected, and power is being generated by an inverter generator, results in virtually no voltage waveform distortion. What this means is that an inverter generator can be loaded to capacity with PFC power supplies. The substantial reduction in line noise that results from using PFC power supplies on the nearly pure power waveform of an inverter generator creates a new math when it comes to calculating the continuous load you can put on a portable gas generator. And if the generator is one of our modified Honda EU6500is inverter generators, you will be able to run a continuous load of up to 7500W as long as your power supplies are Power Factor Corrected. For more detailed information on how the power factor and harmonic distortion of LEDs affect generators, I would suggest you read a series of articles I wrote for Protocol (the quarterly journal for ESTA) on the use of portable generators in motion picture production. For more detailed information about the use of HMIs and Kinos on portable generators I suggest you read my article on that subject. http://www.screenlightandgrip.com/images/generators/BoxBookForumLinkGenSetMed.jpg Harry Box, author of “The Set Lighting Technician’s Handbook” has cited this article in the just released Fourth Edition of the handbook. In addition, he has established a link to it from the companion website for the Fourth Edition of the Handbook, called “Box Book Extras.” Of the article Harry Box states: "Great work!... this is the kind of thing I think very few technician's ever get to see, and as a result many people have absolutely no idea why things stop working." "Following the prescriptions contained in this article enables the operation of bigger lights, or more smaller lights, on portable generators than has ever been possible before." You can find links to all these articles at http://www.screenlightandgrip.com/html/hd_plug-n-play_pkg.html Guy Holt, Gaffer, SceenLight & Grip, Lighting Rental and Sales in Boston.

Given the inherent danger in using electricity in and around water, I am surprised no one has yet mentioned that the National Electrical Code requires the use of GFCIs on all 15- and 20- ampere, single-phase, 125-volt receptacles located within 6.0m (20 ft._ of the inside walls of a pool (Section 680.22 (A)(4). This creates a problem for us because many movie lights (HMIs, Kinos, & LEDs) generate residual currents of sufficient magnitude to nuisance trip most GFCIs. The source of residual currents in these devices can be intentional or unintentional capacitance. Some sources of unintentional capacitance can be the spacing of components on printed circuit boards too close together, poor insulation between semiconductors and grounded heat sinks, and the primary-to-secondary capacitance of isolating transformers within the power supply. A source of intentional capacitance is the use of RF filters to reduce the amount of high frequencies electronic equipment emits into the atmosphere. These RF filters can be a source of appreciable residual current on the Equipment Grounding Conductor that will trip most GFCIs. If you stick with smaller quartz lights, you will be fine with the hardware store variety of GFCI dongles. But, if you use HMIs, Kinos, and LEDS you will need film style GFCIs, like Shock Stops, that are specifically designed for motion picture lights. To prevent the nuisance tripping that electronic power supplies can cause with standard GFCIs, the Shock Stops trip on an Inverse Time Curve. And, to deal with the harmonics that electronic power supplies can generate that will cause most GFCIs to trip, Shock Stops include a narrow band pass filter with a frequency range of 40-70Hz. Attenuated by the filter, the high frequencies in residual current does not cause nuisance tripping. A more accommodating trip curve, plus harmonic filtration, equals nuisance free operation. For more details about the use of GFCIs on set, see my white paper on the use of portable generators. Guy Holt, ScreenLight & Grip, Lighting Rentals and Sales in Boston

I don't have a url for the Film Florida Guidelines, they were sent to me as a pdf by a friend, so I had our web designer upload it to our server and establish a link from our website. You will find the link below the links to Protocol articles I have written over the years. Guy Holt, Gaffer, ScreenLight & Grip, Lighting Rental & Sales in Boston

I would not try to enclose a construction style generator like the DuraMax XP12000EH in a sound blimp - it is likely to catch fire. Inverter generators can be enclosed because they are designed for air flow traveling through the generator from front to back and so can work in enclosures designed with front air intake and rear air exhaust (there are several enclosures on the market for this purpose.) The air guide of the Honda EU7000’s triple-chamber construction is part of what makes it so quiet. Put it in a properly designed enclosure and you have a dead silent generator. The air guide of the Honda EU7000’s triple-chamber construction Construction style generators, like the DuraMax XP12000EH, use an open frame construction for radiant convection cooling, which also makes them a lot noisier. The only way to not pick up the noise of a construction style generator is to get it as far from set as possible. But then you have the problem of voltage drop, called line-loss, over the long cable run to set. Voltage drop consumes power, diminishes the output of tungsten heads, and shifts their color temperature drastically. Another drawback to the DuraMax XP12000EH is that, even though it is a 12000W generator, that 12000W is not available to you in a usable form. Three 2ks will require three 20A/120V circuits, and you will need additional 20A/120V circuits to power anything else since the 2ks will monopolize the circuits they are on. The DuraMax XP12000EH has only one 20A/120V circuit. The larger circuits are 240V, which means that you will not be able to use a 100A lunch box because its five 20A circuits are 120V. Campfire scene on the beach powered by a Honda EB10000 I don’t mean to dissuade you from using a generator like the DuraMax XP12000EH, plenty of productions do. You just have to be smart in how you use them. For example the Adam Laupus film “Gasp” used a Honda EB10000 to power scenes on a beach without picking up the noise of the generator. Left: Honda EB10000 operating out of grip truck (note set at distance (bright spot on right side.)) Center: 84A Full Power Transformer/Distro <br>compensates for Voltage Drop over 400ft cable run. Right: Beach Set with 120v full line level 500ft from power source. As pictured above they ran the generator out of the back of their grip truck, 500’ from set, where it wouldn’t be heard. To compensate for the voltage drop over the long cable run to set, the crew used a 84A transformer/distro with secondary side voltage adjustment which enabled them to boost the voltage on set to get it back to 120V. The transformer/distro also stepped down the 50A/240V circuit they ran from the generator to a 84A/120V circuit. With the transformer/distro on set they then ran 100A Bates Extensions around their set and broke out to 20A Edison receptacles using 100A gang boxes in order to power an assortment of smaller tungsten fixtures to simulate the firelight and an ARRI M18 to simulate moonlight on the actors around the fire. To light the deep background the crew put a 240V Siamese in-line before the transformer/distro to power a 6kw HMI Par. Even with such a sizable load, they experienced no appreciable voltage drop on set after a 500' cable run because the transformer/distro compensated for the line loss of the cable. Left: Beach Set lit by Arri M18 and 6kw Par. Center: Secondary side power distributed with standard 100 Bates Gang Boxes. Right: Set viewed from generator (note: distance and extent of set power distribution.) Another key ingredient to their success was they used the Digital Honda EB10000. As far as I know, the EB10000 is the only construction style generator to use the new digital AVRs (DAVRs.) DAVRs are able to hold the voltage stable within ±1% of the mean voltage (as opposed to the ±3% of the best analogue AVRs.) The EB10000’s DAVR substantially improves the output capability, resulting in less voltage drop under load. What makes the output of Honda’s EB10000 more stable is that its’ DVAR is much more responsive than traditional analogue AVRs. A 10kw Honda EB10000 with a Full Power Transformer/Distro that provides a single 84A/120V circuit. Traditional AVRs use a closed feedback loop to stabilize voltage. As such, it takes comparatively longer to feedback and correct deviations from mean voltage caused by a sudden increase in load. Slower to respond, analogue AVRs allow for larger fluctuations of voltage (±5%), which, for example, can cause an HMI to cut out if the voltage drops too low. Rather than use a closed feedback loop to stabilize voltage, a DAVR uses control software with micro-second sampling rates of the output power of the main Stator windings (as compared to a sensor winding in conventional AVR systems) to more quickly and accurately detect deviations from the mean and make the necessary adjustment to the excitation current in the Rotor electromagnets more rapidly. And, by directly sampling the main Stator windings, rather than a sensor winding, the DAVR obtains a more reliable indication of the output voltage - the same one your loads see. The drawback to using a separate sensor coil is that the AVR does not see how voltage at the generator bus has been affected by changes in temperature, load current, and load harmonics. By applying true RMS calculations to the actual voltage coming off the Stator coils, as opposed to an isolated sensor coil, the DAVR of the EB10000 has a more accurate reading of the bus voltage and so is able to make more accurate corrections (use this url for more details.) With nothing more than a Honda EB10000 and house power the crew of "Gasp" was able to maintain the look and feel of a sunny summer day even when filming in the midst of a hurricane in October. The principal location for "Gasp" was an idyllic beach house right on the ocean. To light interiors of the beach house, the crew of "Gasp" used two 4k Pars outside, and an assortment of smaller HMI and Kino fixtures on the inside. The smaller fixtures were plugged directly into the house, while the 4k Pars were powered by the EB10000 running in the back of their grip truck. Left: Ready for rain on the set of "Gasp." Center: Two 4kw Pars operate on a 10kw Honda EB10000 Generator through our 84A Full Power Transformer/Distro. Right: 100A Shock Block GFCI downstream of the transformer/distro offers Ground Fault Protection for the entire 100A distro system. The indie film "Gasp" is a good example of how a transformer/distro can greatly simply set electrics so that you don’t have to be an experienced electrician to power a set. It makes it possible to record clean audio tracks with even generators as loud as the EB10000 even under the worst of conditions. Use this link to the trailer of "Gasp" to see what can be accomplished on a low budget if you work smart. Guy Holt, Gaffer, ScreenLight & Grip, Lighting Rental & Sales in Boston

It depends on the type of ballast. Because of the constant improvement in HMI technology over the years there are several types of HMI ballasts available and if you are not careful how you power them you can get stuck. In ballast design you have a choice between magnetic and electronic ballasts; and to complicate matters even more, you have a choice between Power Factor Corrected electronic ballasts and non-Power Factor Corrected electronic ballasts. Magnetic ballasts draw more current during the striking phase and then they “settle down” and require less power to maintain the HMI Arc. For this reason, as Phil states, you must leave “head room” for their higher front end striking load. For the same reason you can’t load a generator to full capacity with HMIs with magnetic ballasts. By contrast, an electronic ballast “ramps up.” That is, its’ current draw gradually builds until it “tops off.” But, unless the ballast is Power Factor Corrected (PFC), an electronic ballast will draw more current than a magnetic ballast of the same wattage. Why ballasts of the same wattage will draw appreciably different current has to do with the Power Factor of the ballast. Since Power Factor Correction (PFC) is not mandatory in this country as it is in Europe, you will encounter many non-PFC HMI, Kino, CFL, & LED power supplies. And since, the adverse effects caused by a poor Power Factor go beyond an inefficient use of power, it is well worth understanding Power Factor and why it should be corrected. To learn about HMIs I would recommend an article I wrote on the use of portable generators in motion picture production. Harry Box, author of “The Set Lighting Technician’s Handbook” has cited my article in the Fourth Edition of the handbook. Here is what he has to say about the article: "Great work!... this is the kind of thing I think very few technician's ever get to see, and as a result many people have absolutely no idea why things stop working." "Following the prescriptions contained in this article enables the operation of bigger lights, or more smaller lights, on portable generators than has ever been possible before." Guy Holt, Gaffer, ScreenLight & Grip, Lighting Rental & Sales in Boston

Finally we have a glimpse of what set lighting will look like in the era of Covid-19. As active discussions continue about setting industry guidelines for a safe return to production amid the coronavirus pandemic, Film Florida has released the most comprehensive set of such recommendations yet. Put out on Thursday, April 30, the six-page document by the statewide trade association features 161 recommendations for “clean & healthy” film, TV and digital production sets. According to a recent article in Deadline Hollywood "it spells the possible end of the signature canvas director’s chairs and ubiquitous actors trailers, and the introduction of personalized mics and hairbrushes as well as clear barriers for actors on stage." In addition to general guidelines, the brochure contains detailed recommendations for each department, including grip and electric. It also includes policies for on-set protocol, handling equipment and on-set communications. Use this link to see the complete report. Guy Holt, Gaffer, ScreenLight & Grip, Lighting Rentals & Sales in Boston

Time to get back to the original purpose of this thread: to share the tricks of the trade that will add more to your film’s production values than all the big budget toys found on bloated Hollywood productions. In this thread Varju Chapan asked how to light daylight interiors without 18ks. M Joel W suggested the use of mirror boards, to which Miguel Angel responded " I learnt the hard way that it is better to place a mirror with a light bouncing in it so you don't have to keep adjusting it every 2 minutes.." Working in New England I too learned the hard way that it is better to put a light into mirror boards than count on the sun. Mark Twain once said "if you don't like the weather in New England , wait five minutes and it will change." A smaller light, like a 4k, into mirror boards is a great way to replicate the feel of an 18k on an aerial lift. The objective to putting an 18k Fresnel on a lift at a distance is to replicate the angle and hard parallel rays of the sun. As you can see from the production stills of a Bose commercial below, you can accomplish similar results by bouncing a 4k ARRIMAX from the ground into mirror boards on stands or a lift. This set up gives you the hard parallel light of an 18K at a distance because, even though the light from the 4k spreads, the boards at the window collimate the light by reflecting only parallel rays. You can get away with a smaller light since the distance of the throw is not as far. And you don't have to worry about the sun moving behind a cloud or a tree (as you can see in the stills below, the sun would not naturally shine through the windows of the workshop.) A 4k ARRIMAX is a good choice of light for this purpose since it has a lot of punch for its power and can be powered off a Honda EU6500 or a dryer receptacle with a 60A transformer/distro as pictured below.) In the Bose commercial we warmed up the 4k with half CTO to partially match the tungsten heads inside. Guy Holt, Gaffer, ScreenLight & Grip, Lighting Rental and Sales in Boston

Working in New England I too learned the hard way that it is better to put a light into mirror boards than count on the sun. Mark Twain once said "if you don't like the weather in New England , wait five minutes and it will change." A smaller light, like a 4k, into mirror boards is a great way to replicate the feel of an 18k on an aerial lift. The objective to putting an 18k Fresnel on a lift at a distance is to replicate the angle and hard parallel rays of the sun. As you can see from the production stills of a Bose commercial below, you can accomplish similar results by bouncing a 4k ARRIMAX from the ground into mirror boards on stands or a lift. This set up gives you the hard parallel light of an 18K at a distance because, even though the light from the 4k spreads, the boards at the window collimate the light by reflecting only parallel rays. You can get away with a smaller light since the distance of the throw is not as far. And you don't have to worry about the sun moving behind a cloud or a tree (as you can see in the stills below, the sun would not naturally shine through the windows of the workshop.) A 4k ARRIMAX is a good choice of light for this purpose since it has a lot of punch for its power and can be powered off a Honda EU6500 or a dryer receptacle with a 60A transformer/distro as pictured below.) In the Bose commercial we warmed up the 4k with half CTO to partially match the tungsten heads inside. Guy Holt, Gaffer, ScreenLight & Grip, Lighting Rental and Sales in Boston

Don’t overlook this forum as a resource. I started a thread a while back as a place where we can share indie tricks-of-the-trade for realizing big budget production values on a modest budget. Or, as Phil Rhodes so eloquently put it “by the application of hard-won and exquisitely-realized skill.” It takes more skill to make an indie film than a big budget studio picture. Where a Hollywood production can throw money at a problem, an indie production must work smart. The emphasis of this thread is FILM CRAFT. For the more technically inclined I have posted on our website articles I have written for Protocol Magazine, the quarterly journal of ESTA which stands for the Entertainment Services and Technology Association. In addition to Protocol, ESTA has created a technical standards program to serve the entertainment industry in technical standards related matters. The goal of the program is to create recommended practices, to monitor standards issues around the world on behalf of its members, and to improve communications and safety within the industry. ESTA works closely with the technical standards efforts of other organizations within the entertainment industry, including USITT, PLASA, and VPLT, as well as representing the interests of ESTA members to ANSI, UL, and the NFPA. The Technical Standards Program is accredited by the American National Standards Institute and applies to places of assembly; the production of film, video, and broadcast; theatrical productions; carnivals; circuses; fairs; and similar events in North America. Use this link for my articles for Protocol. Guy Holt, Gaffer, ScreenLight & Grip, Lighting Equipment Rental and Sales in Boston.

To power a small HMI off of batteries for an unlimited time in a car rig you can use a "Battverter" - which is a Battery/Inverter system. A "Battverter" system consists of a 12V DC power source (usually large Marine Cells), a DC-to–AC True Sine Wave Power Inverter, and a Battery Charger. Here is a link to some production stills that show you two Battverter systems I built to run lights in vehicles at various times. The first is a 750W "Battverter" rig wired into a Calzone case. The second is a more elaborate 1800W Battverter system that I built to run 16 - 4’ kinos tubes inside an airport shuttle bus. Use this link - https://cinematography.com/index.php?/topic/70937-indie-tricks-of-the-trade-or-how-to-get-good-production-values-on-a-modest-budget/- for details. Guy Holt, Gaffer, ScreenLight & Grip, Lighting Rental & Sales in Boson

There are two reasons why you should not replace the duplex receptacles on your gang box with GFCI receptacles. First, it is a code violation and, second, they are the wrong kind of GFCIs for the loads we use. First, while the Code permits you to build your own “cord set”, it requires that cord sets utilize GFCI protection listed for portable use. The reason for this is that such GFCIs include "Open Neutral" protection, which enhances personnel safety where such devices are subject to the possibility of losing a Neutral connection. For this reason, it is not permissible to utilize GFCI receptacles designed and listed for permanent installation without Open Neutral protection in portable cord sets. The second reason not to replace the duplex receptacles on your gang box with GFCI receptacles, is that they are the wrong kind of GFCIs for the loads we use. In addition to not filtering residual currents, hardware store type GFCIs use a much more aggressive trip curve than do film style GFCIs like those manufactured by Shock Stop, Littelfuse, and Bender. To understand the difference requires a little background information. To improve the generally poor reliability of early GFCIs, in 2003 UL published a new standard (UL 943) for GFCIs designed to prevent nuisance tripping by transient conditions that are not of a sufficient duration to pose a hazard. The new standard allowed GFCIs to trip on an "Inverse Time Curve." An inverse time curve can be mathematically expressed as I2T where "I" is current and "T" is the time it takes to trip. Since this is a logarithmic equation, the plot of I versus T (as can be seen in graph below) does not follow a straight line but introduces a delay that decreases as the magnitude of the current increases. The advantage to an inverse time trip curve is that it permits transient spikes in leakage that are sufficiently short in duration so as not to pose a shock hazard to pass while keeping current through the body to safe levels. And, as mentioned in my previous post, UL 943 also permits GFCIs to incorporate high frequency filters to avoid nuisance tripping from GFCIs becoming sensitized by residual currents. Attenuated by a filter, high frequency harmonic currents drawn by non-linear loads won't trip or sensitize GFCIs. Even though the UL 943 standard was meant to enable GFCIs to operate more reliably in real world conditions, manufacturers of inexpensive GFCIs, like those found in hardware stores, do not implement the exact UL943 curve because it requires sophisticated micro-processors, which makes the design more complicated and the GFCI more expensive. Nor, do they filter high frequency residual currents for the same reason. Instead they use a more aggressive response (also illustrated in the graph below) that is lower and faster than that required by UL 943 (typically 25ms at 6 mA where UL 943 permits 5.59 seconds.) This more aggressive trip curve and lack of filtration does not generally pose a problem in the one-tool per circuit applications for which hardware store GFCIs are designed. After all, power tools are by their nature linear loads that do not draw high frequency harmonic currents. However, the more aggressive trip curve of this style of GFCI has proven to be a problem in applications involving non-linear lighting loads, namely the type of lights increasingly used in motion picture production. And, with the number of LED fixtures that have non-pfc power supplies increasing on set, nuisance tripping of inexpensive GFCIs will only become more frequent. So what’s a set electrician to do? Fortunately, NEC Section 215.9, Ground-Fault Circuit-Interrupter Protection for Personnel provides general permission for a feeder to be GFCI protected where it supplies 15- and 20A receptacle branch circuits requiring GFCI protection under Section 210.8. The section reads as follows: “Feeders supplying 15- and 20-ampere receptacle branch circuits shall be permitted to be protected by a ground-fault circuit interrupter in lieu of the provisions for such interrupters as specified in 210.8 and 590.6(A).” Since this section prescriptively identifies feeder GFCI protection “in lieu of” that required in 210.8, it permits the use of film style GFCIs (like the Shock Block SB100, LifeGuard LG100, and Shock Stop 60-100), with 100A Lunch Boxes to satisfy the recently expanded Section 210.8 requirement for GFCI protection on all single-phase branch circuits outdoors rated 150 volts to ground or less, 50 amps or less. This is good news for us since film style GFCIs, like the LifeGuard, Shock Block, or Shock Stop are a lot less prone to nuisance tripping because, unlike hardware store GFCIs, they employ high frequency filters and a trip curve that more closely approximates the inverse-time curve of UL943. Guy Holt, Gaffer, ScreenLight & Grip, Lighting sales and rentals in Boston

Do a Google search for Shock Stop GFCI in parenthesis, that is enter "Shock Stop GFCI" in the Google Search Bar.

I think you should hire a Gaffer that will keep you Code compliant. I salute your desire to learn but there comes a point where you can't expect to know everything and should hire a "Qualified Person." In Code parlance a Qualified Person is someone who has received formal training in the hazards posed by electricity and how to mitigate it. When it comes to using electricity a little knowledge can be dangerous. It may not seem like it, but this is a very complicated question. The Code requires that ground rods be 10ft, driven all the way into the ground, and the impedance to earth of the driven rod be no more than 25Ωs . If you are not able to satisfy this requirement with one rod, the code allows you to satisfy its requirement by driving a second rod not less than 6ft from the first. However, Honda EU6500s and EU7000s meet the Code requirements to be exempted from its grounding electrode requirement. They do not however meet OSHA's requirements to be exempted. To complicate the issue further, the NEC is a uniform code that is adopted into law in whole, or in part, by the local "Authority Having Jurisdiction" or AHJ. It is not uncommon for the AHJ to modify or augment the NEC in adopting it into law. For instance, in the City of Los Angeles you are not required to ground generators, but here in Boston we are required to ground generators. In the city of Boston, we are not permitted to use gas generators, but must use diesel generators. In short you need to check with the AHJ where you are shooting to see what the requirement is. To complicate the issue even further, the Code is the minimum required for electrical safety. Even though it does not require a Honda EU6500 or EU7000 to be earth grounded there are, IMO, good reasons to ground Hondas. For one, GFCIs will operate more reliably if they are, but that is more than I have time to get into now (perhaps later if you are interested). If you have not already, I suggest you read my white paper on the use of portable generators in motion picture production. It is available at http://www.screenlightandgrip.com/html/emailnewsletter_generators.html. Guy Holt, Gaffer, ScreenLight & Grip, Lighting rental and sales in Boston.

The Code article that mandated that any portable generator under 10kW with 240V output be GFCI protected grandfathered generators manufactured before 2014 which permits rental houses to continue to rent their EU6500s with Bates modifications. It does not, however, exempt the users of those generators from the Article 210 general requirement for GFCIs on outdoor circuits of 150V to ground or less, and 50A or less. To meet this requirement electrical manufacturers like Woodhead and Hubble introduced inline 120V and 240V 30A GFCIs, but since the 50A Bates mod was an after market modification done on a very limited scale, large manufacturers like Woodhead and Hubble did not see a market for an inline 50A/120V GFCI. Which means that until Shock Stop introduced their inline 60A /120V GFCI (pictured above) the only option was to use one of the 100A/120V Shock Block GFCIs manufactured by Littelfuse or Bender. The ability to use high amperage "film style" GFCIs like those manufactured by Shock Stop, Littelfuse, and Bender to provide the Code mandated GFCI protection required on the 20A receptacles of lunch boxes and gang boxes is a huge benefit to us because the alternative, hardware store style GFCI dongles, are prone to nuisance tripping with many motion picture lighting instruments. Thats because many of the manufacturers of lighting fixtures that use electronic power supplies (HMIs, Kinos, & LEDs) shunt the harmonic currents they generate to their equipment grounding conductor as a means of reducing RF. Since these harmonic currents, called residual currents, return to their source via the equipment grounding conductor rather than the neutral, inexpensive hardware store GFCIs sense a current imbalance and trip. Such trips are a nuisance because the residual currents these power supplies generate do not pose a shock hazard. What makes high amperage "film style" GFCIs like those manufactured by Shock Stop, Littelfuse, and Bender worth the extra expense is that they filter high frequency currents and thereby are not tripped by these residual currents. For this reason it is far better to use a high amperage film style GFCI just upstream of a lunch or gang box than to use 15A hardware store GFCI dongles on the 20A outlets of a lunch or gang box as pictured below. Guy Holt, Gaffer, ScreenLight & Grip, Lighting rental and sales in Boston

The inspector that shut down the grad student thesis film I gaffed didn't care a bit that it was a non-Sag micro-budget student film. Guy Holt, Gaffer, Screenlight & Grip. Lighting rental and sales in Boston

Impugning my motives won't change the facts. Take a look around your EU7000. It is designed to be compact and quiet. To be compact there is no wasted space. To be quiet there is a steel wall between the electrical compartment behind the power panel and the rest of the generator, which means there is no place else to put the Bates connector. We used to offer this mod and if it were still possible I would happily do it for you, but it is practically impossible after the power panel was redesigned to accommodate GFCIs. Not true. The NEC is written in blood. Everyone of its requirements is the result of someone being injured or property damaged. The NEC requires GFCIs on Hondas because they present, and have always presented, a particular hazard. What happened was Hurricane Katrina when there was a surge of electrical injuries from the operation of portable generators. Because they are designed primarily for home standby power, the Honda EU6500s and 7000s do not bond the equipment grounding conductor to the neutral of the generator as required by OSHA. Without a Neutral/Ground bond, as illustrated below, a multiple fault condition exposes an individual touching faulty equipment to 240 volt potential which is lethal. The NEC is law in all 50 states, the AHJ (or OSHA most likely) will enforce this requirement and shut down your production. Years ago I gaffed a grad student thesis film project that was shutdown by the electrical inspector because he happened upon our set on his way home from work. Guy Holt, Gaffer, ScreenLight & Grip, Lighting Rental & Sales in Boston

Slow down. As someone who used to offer this mod (the picture above is from our website) and can no longer do so, I can tell you that even if you could find someone to do it these days (I doubt you will) I wouldn't do it. While the modification was very straight forward with the Honda EU6500, there are mechanical issues that make it very difficult on the Honda EU7000. And, since January of 2020 there are now Code issues that make it illegal in many states. For these reasons, any responsible shop that used to do the mod no longer does so. Let's look at the mechanical reasons first. Starting with the 2017 Code, the NEC mandates that any portable generator under 10kW with 240V output be GFCI protected. To make it code compliant Honda has put GFCIs on the latest edition of the EU 7000 leaving no room for the 60A Bates on the redesigned power panel. Those companies that continued to offer the mod (Multiquip) could only do so by completely removing the 30A Twist-Lock from the panel, moving the control circuit board, building in overcurrent protection, and machining a cover plate to cover the hole in the panel left by the 30A Twist-lock. They also had to silk screen onto the cover plate the warnings required to reduce their liability. Of course all this was not UL tested and so voided the UL listing of the generator. Fast forward to January 2020. The 2020 edition of the Code greatly expanded GFCI requirements to include all outdoor circuits of 150V or less to ground and 50A or less whether fixed or portable. Since the Bates mode provided 50A at 120V it now requires GFCI protection which is why I suspect even Multiquip will discontinue offering the modification. The only way to get a 60A circuit capable of powering a 4kW HMI or 5kW Tungsten light out of a Honda EU6500 or EU7000 is to use a small step-down transformer to convert the 240V output of the generator to 120V. Since this circuit is 60A at 120V it is not required by Code to be protected by a GFCI. The NEC is the minimum required for electrical safety on set. Our industry standards writing group, ESTA, recommends the use of GFCIs on all branch circuits of 100A or less. For this reason we now offer a listed 60A GFCI that can be used on a step-down transformer, or on any 60 or 100A Bates circuit to provide unparalleled ground fault protection. And since NEC Section 215.9 permits the use of a GFCI on the feeder of branch circuits requiring GFCIs, it can also be used to provide the GFCI protection required on the 20A circuits of gang and lunch boxes as pictured below. Guy Holt, Gaffer, ScreenLight & Grip, Lighting rental & sales in Boston.