underwater lighting safety

[Iskra Valtcheva]

Hello,

 

I am writing with a safety concern about an upcoming low budget underwater shoot. Basically, the DP wants to use a regular 4x4 kino bank submerged underwater; to me, that sounds like a reckless and irresponsible scenario. I recommended renting Hydro Flos and suggested alternative lighting scenarios where lights do not get put directly in the water. However, he claims he's done it before with no ill effect; and says it will be fine as long as the ballasts are kept well out of the water since we are dealing with low wattage and high frequency electricity. We will have GFI's and will insulate connections but I am still not convinced and don't want to sign off on an iffy and potentially hazardous setup. What if a ballast malfunctions? What if a tube breaks? What if a GFI fails? Has anybody done an "experiment" by throwing a kino in the pool and going for a swim?

 

I am new to the trade but everything I've learned so far tells me this is a bad idea and will potentially endager the cast and crew's safety (yes, they are planning on having crew and cast in the water!)

 

Any comments/advice/insight?

 

Sincerely,

Iskra Valtcheva

[Jonathan Bowerbank]

Your DP's correct, so long as the ballast is out of the water, the Kinoflo and your actors are perfectly safe.

[Andrew Koch]

If it were safe to stick regular kinos in the water, then why would they even bother to make underwater kinos? Let me state that my experience with underwater photography is very limited so I tend to always play it safe when in doubt (I was even nervous at one time when I had to operate an underwater par in a pool that was designed for such use. My lack of experience made me paranoid.) How would you plan on "insulating" the connections? With latex? Are you insulating each connector for each bulb? Can you guarantee that the insulation is safe? Is your GFI a class A? PACE WETSET Kinos for example have the bulbs inside additional plastic tubes. I think you have a very good reason to be concerned and if I were you I would not sign off on this until you have talked with an experienced set electrician. Many DPs might not be qualified to give you a definitive answer. I certainly am not qualified. Obviously there are some very knowledgeable and experienced people on this board, but if anything goes wrong, saying "I read on an internet forum that it was safe" is not going to cut it. Call PACE WETSET and Hydroflex and ask them about this. Obviously they might be biased toward their products, but they may have some insights about this. If anyone on this board tells you it is safe, ask them to qualify this answer.

 

To sum it up, be extremely careful and never be bullied into putting people even into slight danger in order to save production money.

[Michael Morlan]

I am the aformentioned D.P. :P I and I appreciate Iskra's need, as the project's gaffer, to feel absolutely assured of the safety of the cast and crew. After all, I'm one of the people who will be in the water! I also applaud Iskra's seeking answers from such august company as can be found on this forum.

 

While I have not been able to find definitive references regarding Kino's underwater, I have safely used Kino 4Bank Select heads in two wet conditions:

 

o mounted on a car during a rain storm (with ballasts sealed in plastic bags), and;

o submerged in a swimming pool (with the ballasts secured on the deck).

 

The reason Kino heads are safe in water is that they operate at 25kHz. That fact, alone, would allow instruments running at hundreds of volts and many amps to function safely. (Read anything about Tesla coils and you will understand the operational theory here. The dangers of Tesla coils are not the electricity being discharged by the system, but the potential to come in contact with the low-frequency primary and the heat of plasma arcing from the secondary into the air.) In simplest terms, the high frequency of Kino's reduces the size of the electrical field within the conducting medium and current simply cannot reach a person beyond a couple inches from the instrument and cable connections much less pass deep into tissues, resulting in electrocution.

 

In the above submerged scenario, I directly handled the Kino heads while in a chlorinated pool without any ill effect. (I did feel a mild shock when adjusting one of the connectors and the circuit to the tube was momentarily broken. The electrical field was approximately two inches around the broken connection.)

 

There is one health hazard to consider, however. Pacemakers can be disrupted by Tesla coils so one might conjecture that there is a very tiny possibility that a Kino could create a similar disruption.

 

The bottom line for this project is that if Iskra feels uncomfortable with the notion of submerging Kino's, we'll find another way to light our underwater greenscreen. While I am her mentor as a D.P. and gaffer, I have entrusted her with the responsibilities of the position and will abide by her ruling on this set.

 

All my respect,

 

Michael

[Jess Haas]

I believe that atleast one of the kinoflo manuals used to say that they could be used underwater. I don't believe that it said anything about the safety of actors or crew in this situation. There no longer appears to be anything in the manuals about using them underwater.

 

I have been told that a kino will function underwater and I believe it. There are a number of reasons for this. While live connectors are exposed to water, under normal circumstances water isn't that great of a conductor so most of the power will take the path of least resistance and flow back to the neutral. The electricity will create an electrical field around the connectors and if it comes into close enough proximity to anything grounded electricity will leak to ground. A person could become part of this path to ground which is where the safety hazard comes in. Some power may even leak between the hot and neutral conductors.

 

Normally a short such as this would cause the circuit breaker to trip. This is not the case with fluorescent fixtures since the ballast functions to limit the current running through them. This means the breaker will not trip if a short occurs.

 

Kinoflos do not use waterproof cables or connectors. This means that over time water will leak into the cables. Besides being bad for them this can greatly increase the chances of shorts and electrical leaks which could lead to serious problems.

 

At 120v it normally takes about 60ma of current flowing through an adult human body and passing through the heart in order for their heart to stop. That is if current goes in one hand and out the other or in one hand and out the foot, etc.... When wet it will most likely take even less current in order to have the same effect.

 

A kino flo ballast sends 800ma at 230 volts to each bulb. So for a 4 bank kino that would mean that there is 3.2amps of 230 volt power, obviously much more than the less than 60milli-amps necessary to stop the human heart.

 

In order for someone to be killed like this while using a kino underwater a part of their body would have to come in close enough proximity to the power and another part of their body would have to be in close enough proximity to ground. This will not always be the case and as a result people have used them underwater without killing anybody. I do not believe that makes them safe. There are lots of possible sources of ground available in a pool and water greatly increases the likelihood that power from that light will find its way through you to it.

 

There are way too many variables involved in using stock kinos underwater for them to really be safe to work with.

 

When using any sort of power around water it should be connected through a Class A GFCI. This device will shut off power if over 60ma of power leaks to ground. They should be located close to the source of power where they themselves can not get wet and so that there is no unprotected power running where it could get wet. They should be tested before each and every use because they can fail. They should also not be used as a sole means of protection because there are many circumstances in which they are not enough.

 

If one were to use stock kinos underwater they could try to add a measure of safety by adding GFCIs. There is a good chance that this would result in the GFCI tripping a lot which would ultimately make the combination either unusable or atleast a pain in the ass. There are also a number of reasons that it would not provide enough protection to keep someone from getting injured or killed. For one the GFCI could fail. They are rather inexpensive devices that can fail, and in my opinion should not be used a sole means of protection. GFCIs also were not designed to protect people underwater. It is possible that a wet person will be injured before the GFCI cuts off power and even if it does not stop their heart it could cause them to drown. People with heart problems, the children and the elderly are much more likely to be killed at lower currents.

 

It is also possible for current to flow out of the fixture, through an individual and back into the neutral. This would most likely occur with a broken bulb or a break in the cable. The GFCI provides zero protection for this since no current needs to leak to ground for it to occur.

 

Regular lights have been used underwater in many films. Even many tungsten fixtures will function underwater. This does not mean that they are safe and there is a reason that underwater lighting fixtures have been developed by companies such as Hydroflex and Pace Technologies. These underwater fixtures have become the industry standard way of doing things and if something goes wrong when using regular fixtures underwater you will probably have very little chance of winning the resulting court cases.

 

Underwater lights are actually not very expensive. Hydroflex's Hydroflos start at $100/day, Tungsten lights start at $85/day and their HMIs start at $250/day. These are all rather comparable with their above water counterparts and even if you have to ship them they should not be a very hard sell.

 

Another way that I have lit underwater scenes on many occasions is by pointing Pars down into the pool and then bouncing the light. The fixture stays dry at a safe distance and the light gets where it needs to go. When doing this make sure to secure the fixture well so that it can not fall in to the water, and make sure that all power is on class A GFCIs.

 

~Jess

[Jess Haas]

The reason Kino heads are safe in water is that they operate at 25kHz. That fact, alone, would allow instruments running at hundreds of volts and many amps to function safely. (Read anything about Tesla coils and you will understand the operational theory here. The dangers of Tesla coils are not the electricity being discharged by the system, but the potential to come in contact with the low-frequency primary and the heat of plasma arcing from the secondary into the air.) In simplest terms, the high frequency of Kino's reduces the size of the electrical field within the conducting medium and current simply cannot reach a person beyond a couple inches from the instrument and cable connections much less pass deep into tissues, resulting in electrocution.

That isn't quite right. Check out "The skin effect myth" section at http://en.wikipedia.org/wiki/Solid_state_Tesla_coil

 

At 25khz electricity can penetrate the human body just fine since it is a relatively poor conductor. The high frequency has even less of an effect on electricities ability to penetrate water.

 

At that high of a frequency the human nervous system isn't effected as much which is why you don't feel shocks from a tesla coil. That doesn't mean electricity can't cause damage. Tesla coils also tend to operate at very low current levels.

 

The higher frequency does make it safer but I am not convinced that it is safe enough. I am also concerned about the fact that the failure of certain components within the ballast could cause electricity at lower frequencies to get into the water. This might not be readily apparent.

 

Lower frequencies might already be provided by the ballast as a start up current.

 

The fact that you felt any shock at all makes me think that bad things could happen.

 

Another thing to be concerned with when using GFCIs is that the the nature of the ballast may actually mask ground faults causing it not to trip. This depends a lot on the design of the ballast.

 

I can't say for sure that using stock kinos in the water is not safe, but until someone can prove to me without a doubt that it is and that there are failsafes for all reasonable failure modes I would not get in the water with them nor would I put anyone else in the water with them. Until then I will keep renting hydroflos.

 

I would really like to get some engineers from kinoflo involved in this discussion, as well with the guys from hydroflex and pace.

 

 

Another issue is the fact that pressure increases with depth and that fluorescent bulbs were not meant to hold up to that kind of pressure. I would say that when submerged they would instantly become more fragile, and at some point they will implode, but I don't know what depth that would be at.

 

~Jess

[Walter Graff]

"I would really like to get some engineers from kinoflo involved in this discussion,"

 

Simply ask Kino flo. You'll be surprised by the answer. Call or email Jim Quisenbury at jquisenburry@kinoflo.com or 818-767-6528

[Michael Morlan]

I PM'd Jim asking him to reply to this post.

 

The email is

Jquisenberry@kinoflo.com.

 

Michael

[Iskra Valtcheva]

Thanks everyone for the quick replies and especially the ones who took the time to explain why they think this is safe or not. This has been truly helpful and informative. Thanks Michael for joining the open discussion, and thank you for your patience and understanding as I'm figuring this out. This forum rocks.

 

I actually already contacted both Jim (manufacturing engineer) and Edgar (director of manufacturing) from Kino Flo yesterday with my questions. I just invited them to the forum today and am looking forward to what they have to say.

 

I also called several local union electricians asking about advice and most of them said "don't do it". One said "it might work, but i wouldn't sign off on it". I bet it could make for an interesting stand-alone experiment. As long as no cast or crew are involved in the formula.

 

Later Vader!

~iskra

[Phil Rhodes]

Hi,

 

This has been asked before - if you get a useful reply from Kino Flo, please post it or paraphrase it here so we can direct people to it in the future.

 

For my own part, I'd take the same attitude that's already been mentioned - it'll probably work, but you're asking for trouble.

 

Phil

[Jess Haas]

Well Jim is going to get a lot of emails then because I also emailed him about it :-) I also emailed representatives from Hydroflex and Pace Technologies to get their take on the matter. I may even try to get a physics professor and an electrical engineer involved in the discussion shortly ;-)

 

I am still of the opinion that while it may work there aren't sufficient safeguards in place to make it safe. If I can get a few of my questions as to how the kinoflo ballast functions and how how electricity behaves under certain conditions it might be possible to come up with a set of guidelines and procedures for how and when it can be safely done.

 

~Jess

[timHealy]

Personally I have used 120 volt par bulbs underwater with a homemade water proof connection plugged into a GFI at a dry spot by a stage box and it worked well.

 

Since a fluorescent bulb is completely sealed like a par bulb, I could see a Kino working underwater. But regardless of the thories, I would prefer water proof headers, harnesses and bulbs connections just to be safe.

 

I'm looking forward to Jim respones too.

 

Best

 

Tim

[Michael Morlan]

I finally got these from my producer:

 

 

 

:rolleyes:

[JD Hartman]

I finally got these from my producer:

 

[ :rolleyes:

 

Just what does this prove? That a Kino can be operated underwater? That a Kino can safely be operated underwater? That using a Kino in this manner is a good idea?

[Michael Morlan]

Just what does this prove? That a Kino can be operated underwater? That a Kino can safely be operated underwater? That using a Kino in this manner is a good idea?

 

JD, Despite your combative tone, I will answer clearly. Yes, the pictures do illustrate that in the case of the shoot I did, the Kino's operated safely in water with personnel. I would not assert, however, that Kino's would be safe in all situations since my evidence is anecdotal, not scientific. My choice to originally sink the Kino's was based on my childhood experiments with and study of Tesla coils - high-current, high-voltage, and high-frequency devices that, with proper understanding, can be handled safely by humans. I reviewed that information before the shoot and came to the conclusion that the electrical characteristics of Kino heads are very similar to that of a Tesla coil - low-current, medium-voltage, high-frequency. I conducted a personal test with the head in water, me on the deck manipulating the head, and safety personnel standing by. Only upon that successful test, did I approve the heads for use in the shoot.

 

We did our underwater shots last night for the feature Iskra is gaffing and we did not use the Kino's because Iskra would not sign off on it. As I mentioned in an earlier post, I gave Iskra the responsibilities of gaffer and I would not override her decision despite my own experience and role as her mentor.

 

We used tungsten lighting on the deck with class A GFCI's protecting all circuits and a grip standing by at the breakers in the event of an emergency. We had five PADI certified divers in the water or on the deck including our first a.c., second a.c., two grips and our set medic.

 

BTW, Jess: A Class A GFCI trips at 5ma. Class B, meant specifically for underwater pool lighting, trips around 20ma. This from UL:

UL PDF Article

 

Oh, and a note about the lighting since we're on cinematography.com: We tried to light our green screen from above through diffusion but could not eliminate the caustics so we switched from green screen to a black solid as the background and will let that serve in the final picture.

[JD Hartman]

Mike,

Sorry it came across that way.

I've had my share of shocking experiences and have had the one and only high frequency burn I ever want to experience. I agree with you and my point is that this a professional forum, nothing should be anecdotal. I wouldn't rely on a GFCI or arc-fault breaker insuring my safety in this instance.

[Jess Haas]

Woops, your right about the GFCI numbers. I even knew that it was 5ma but I guess thats what I get for writing while I am tired. Thanks for the correction! There is also one more error that I noticed in one of my posts. The amperage numbers that I put were based on numbers from the kinoflo site which are based on 120vac. I believe that the bulbs area actually running at a higher voltage but I am not certain what it is. It is most likely something in the 230-320v range. That means that the amperage being sent to the lamp is roughly half what I previously stated, so about 1.5amps.

 

My choice to originally sink the Kino's was based on my childhood experiments with and study of Tesla coils - high-current, high-voltage, and high-frequency devices that, with proper understanding, can be handled safely by humans.

Tesla coils are relatively low-current devices. As the voltage is increased the amperage is decreased. That is if power is a constant of course.

 

I reviewed that information before the shoot and came to the conclusion that the electrical characteristics of Kino heads are very similar to that of a Tesla coil - low-current, medium-voltage, high-frequency.

I would not call kino heads low current. The voltage isn't nearly as high as with a Tesla coil and they have a decent amount of current running through them. When operating normally a 4x4' kino head will have about 1.5amps running through it(could be higher if the voltage they are operating at is lower than I think it is). The ballast functions to limit this current but if it were to fail this number could be significantly increased.

 

Your experience with using kinos in the pool shows that it has been done and no one was hurt. This does not prove that it is safe, simply that in a particular instance no one was hurt. No one has proven that it is unsafe, but until proven otherwise I prefer to consider it unsafe. When I do underwater shoots my life and the life of many other people are in my hands and I prefer to err on the side of caution.

 

~Jess

[Jess Haas]

I wouldn't rely on a GFCI or arc-fault breaker insuring my safety in this instance.

I like to use GFCIs as a redundant safety measure not as primary protection. I will also often use two GFCIs on a line since most outlets near pools tend to be GFCI protected already and I prefer to add my own devices. I of course test both devices before use. As primary protection lights should be secured to where they can not fall in the water and underwater lights should be properly sealed.

 

Even if a GFCI functions properly there is still a chance for it to shock you before shutting off the circuit. I have tested them in the past and a short to ground is capable of creating quite a spark before the GFCI shuts the circuit off. Also hot to neutral shorts will not be detected by a GFCI and as such they provide no protection against them.

 

Arc-fault breakers should never be relied on for people protection.

 

~Jess

[Walter Graff]

I was hoping someone would have gotten an answer from Kino Flo already but as Mike has shown the answer is that you can use Kinos underwater. We have been doing it since they were invented. I even used them in a lighting design of a $500,000 bar mitzvaha I was hired to light last summer in the Hamptons. We used 140 fixtures of various types to light 5 acres of land in all sorts of colors and animated designs. I used Kinos in the two pools gelled to create some pretty cool effects. It's one of the great features of the fixture. Albeit I would not do so without a GFCI circuit, just as I would not use any fixture in ANY wet area without a proper GFCI circuit for protection. Technically according to the NEC code you have to. Two GFCI breakers on the same circuit don't offer you anything more than redundant protection, not better, just redundant. Now of course like many issues in the film world you have liability. If there were some instance of electrocution or shock that caused something like diagnosed heart palpitations, you can bet that your company would be held liable because any malpractice attorney would jump all over the fact that technically Kino Flo does not make the fixtures specifically for underwater use. I do remember a few years ago that KinoFLo mentioned in their literature that folks had been using them for all sorts of things including underwater, and I know that most of the guys I work with know you can use them underwater and in the rain easily. But it always comes back to two issues, knowledge and understand. Take tie ins for instance. Only a licensed electrician is permitted to do such a thing, but it is done by unlicensed people knowledgeable of the methods all the time. Of course if there were a problem, litigation could exist, but that is another story.

[Phil Rhodes]

I think this discussion is getting very dangerous. The characteristics of a group of people convincing each other that something stupid is a good idea are readily apparent here - am I the only person who can see where this is going? I'm going to bow out of this particular piece of groupthink having said this:

 

The fact that it worked once doesn't mean it will work again. The fact that nobody got hurt does not mean it is safe. The fact that it may work does not make it a good idea. The fact that it is convenient and cost-saving does not make it correct.

 

Anybody who does this without official written sanction from the manufacturer, which I suspect you will not get, is a cloth fool and deserves every bit of trouble they get.

 

Phi

[Jess Haas]

Albeit I would not do so without a GFCI circuit, just as I would not use any fixture in ANY wet area without a proper GFCI circuit for protection. Technically according to the NEC code you have to.

One question I want answered is whether the transformers in a kinoflo ballast isolate the fixture from some of the protection that a a GFCI provides. Something I read recently gave me the idea that it is possible for a transformer to do just that.

 

Two GFCI breakers on the same circuit don't offer you anything more than redundant protection, not better, just redundant.

When I use two redundancy is exactly what I am after. When I go to a location that has GFCIs installed I very rarely know the history of the units. While they may trip when I press the test button that doesn't mean that it certainly will the next time there is a current leak. I prefer to add my own unit that I know the history of and that I know to be in working order. Adding it on top of the other one just adds a little bit of redundancy in case one of them was to fail.

 

Take tie ins for instance. Only a licensed electrician is permitted to do such a thing, but it is done by unlicensed people knowledgeable of the methods all the time. Of course if there were a problem, litigation could exist, but that is another story.

Actually I believe the NEC says only a qualified individual can perform them, not a licensed electrician. Some municipalities have gone out of their way to define this as a licensed electrician, but I do not believe that to be the case everywhere. That being said I am no expert on the matter, if someone can point me to something that says otherwise I would gladly read it. I will say that many people who do tie-ins are not really qualified individuals.

 

~Jess

[Eric H]

So, if I want to light a body of water such as a pool or the like and the existing built in lighting sources are either not matching or otherwise unacceptable AND a human will NOT be in the pool, then this method will be fine? Other than the possibility of damage to the Kinos from leakage or being crushed at a certain depth, of course. anyone know at what depth a 4ft Kino will implode?

regards,

Eric

[Jonathan Bowerbank]

If it's safe enough for David Mullen to get into a pool with a rigged Kinoflo standing in and over it, it's safe enough for me. ;)

 

From the StudentFilmmaker article: "The Kinoflo in the water had a ground fault circuit interrupter."

 

 

Pardon my feeble scanner

Edited November 28, 2007 by Jonathan Bowerbank

[Jonathan Bowerbank]

That's from the May 2007 issue, by the way :)

[timHealy]

If it's safe enough for David Mullen to get into a pool with a rigged Kinoflo standing in and over it, it's safe enough for me. ;)

 

From the StudentFilmmaker article: "The Kinoflo in the water had a ground fault circuit interrupter."

 

 

Pardon my feeble scanner

 

Sorry if I am splitting hairs but that Kino Flo in the water is different than the jist of the thread. That Kino is not submerged.

 

Best

 

Tim