tying in to house power

[christohershaun@pacbell.net]

Unfortunately it?s that time in my career when I?m starting to be requested to tie in to house power.

 

I?m not at all happy about possibly kicking this fresh turd on a hot day but???

 

Other than DON?T could I please have some help and pointers in doing this safely without violating any regulations?

 

Thank you

 

 

Chris

[David Mullen ASC]

Only a trained electrician should do this, probably someone licenced in some way. I think in many cities, it's the law. No one is going to feel comfortable describing the steps to tying-in over a forum post!

[J. Lamar King IMPOSTOR]

It's probably the law everywhere (in the U.S.) that only a licensed electrician is allowed to tie in. If you need amps, you could tap the 240v socket that most houses have. They run around 30 or 40 amps. You still need to make sure you aren't going to fry something.

[Nate Yolles]

This was posted by a talented union gaffer friend over on CML and I think it sums it up perfectly.

 

There are so many issues with tying into a circuit panel--where do I begin?!

I will try to give you some ammunition here to convince production to get

you a generator.

 

1. Set Lighting Technicians are not Electricians. Our responsibility and

training is from the "Buss Bars" out. Liability wise only a Licensed

Electrician or IBEW Electrician is authorized to tie in power.

 

2. CAL OSHA regulations will show you that tying in temporary power into an

existing circuit breaker panel and not securing the panel completely is in

violation of safety codes. Also, if you are tying into the main feed of a

circuit breaker panel, and not into individual breakers, you are now

violating electrical and safety codes and it is usually impossible to close

the panel with five pieces of wire coming out of it. It is completely

against regulations to not completely close the panel. Also, those panels

are rated for the loads of the circuit breakers, if you add "movie light"

loads, you will be overloading the rated capacity for the panel. Also if

you "tie in" to the main feed for a panel, you have eliminated a "main

breaker" or safety switch between all of your equipment and the main power

source---very dangerous and very illegal.

 

3. You are personally responsible for all of this if anything goes wrong or

if any one gets hurt or killed.

 

Years ago I used to tie into all kinds of panels for all kinds of shows.

Its not hard to do, and it will provide the electricity you need, usually.

However, I have realized that there is no reason to do this, and the cost of

a generator is a small bit of insurance to avoid disaster, injury, death,

and or fines. Do it right or don't do it. That's my advice.

 

Mike Ambrose

Gaffer

Los Angeles

Edited November 22, 2004 by Nate Yolles

[Mike Hall]

David is, as usual, spot on. A tie-in used to be common practice in our industry, but accidents and liability issues have made the tie-in more risk than savings.

 

First there is the very real possibility that you could be killed in the act. Then, one must consider liability issues and local law. Many municipalities have enacted stiff fines (in Phoenix the fine is $25k per incident) for hooking up "temporary" power distribution without an inspection and permit. If this is the case, and you do tie in, the power tie in might be considered an illegal act, and therefore may be excluded from insurance coverage. If something did go wrong, or someone including but not limited to yourself was killed, there could be sticky coverage/liability issues.

 

If you do absolutely have to tie in, you might want to hire or consult an IATSE gaffer, or as David said, a licenced electrician. Many times the Union has covered the proper safety and liability issues for their members, and if nothing else, you can get a second opinion.

 

Anyway, something to think about.

 

Mike

[christohershaun@pacbell.net]

Hey guys,

 

Exactly as I thought.

 

This one's not for me.

 

Thanks for the prompt responses.

 

 

Chris

[John Sprung]

30 years ago I used to do this all the time. They even taught it in film school. DBS and DWP only cared if you tapped ahead of the meter, or blew a positect. They just wanted to get paid for the power.

 

Our society has grown timid and litigious since then. Film has grown faster, and lights more efficient. So, tapping is history.

 

 

 

-- J.S.

[Michael Morlan]

If you need amps, you could tap the 240v socket that most houses have.  They run around 30 or 40 amps.

<{POST_SNAPBACK}>

 

That is such a great idea! I hadn't thought of that simple maneuver before. Has anyone done this? Would it be legal?

 

Seems to me, all one needs is a custom distro setup with the twist-lock plug, sufficient feed cable, and lunch box(es) with 120v legs properly identified.

[Guest Andy Sparaco]

Most modern homes and apartments have a 220/240 plug for a dryer or range . it is quite simple to have an electricain wire up a plug with 100ft heavy three lead cable which ends in a small break out box with circuit breakers and a switch. You will get 5000 watts at120volts for 40 amps. Smarter play is use 220 lamps and get 10,000 effective watts. You should also locate and mark the breaker box which feeds the plug. We carry a set of these "trick plugs" and on location saves lots of popped breakers and hence delays

 

ATTEMPTING TO PLUG A FULL ON DISTRIBUTION SYSTEM THRU THIS PLUG IS DANGEROUS AND STUPID!

[Michael Morlan]

Most modern homes and apartments have a 220/240 plug for a dryer or range.

 

ATTEMPTING TO PLUG A FULL ON DISTRIBUTION SYSTEM THRU THIS PLUG IS DANGEROUS AND STUPID!

<{POST_SNAPBACK}>

 

Andy, I would imagine so! :blink: I would design a smaller distro setup with capacity under that of the supply. That 30 amp capacity for smaller projects is still more convenient than hunting circuits around the location.

 

One addendum to your note about 120v loads on a 240v dryer outlet:

 

Each 120v leg of the circuit is rated at the amount noted on the dual breaker. So if you have a dual breaker, with each breaker rated at 30amps, then each leg is rated at 30 amps, for a total of 60 amps at 120v. BUT, ONLY IF YOU KEEP THE LOAD BALANCED! :o

 

As with any multi-leg distro system, you want to maintain a balanced load between the hot legs to minimize the current on the neutral leg. I typically try to keep any imbalance within 2000 watts on a typical 2-leg 120amp set distro setup.

 

Naturally, it's better to work under the max capacity to leave a safety margin.

 

And, of course, when powering from a location, you shouldn't exceed the total load being drawn by both your set and the location as well as maintaning the total location/set balance. That's when an ampmeter across the feed wires comes in handy. (Of course that means you're opening the breaker box again, which is right out in this context.) :D

Edited November 25, 2004 by mmorlan62

[Phil Rhodes]

Hi,

 

Just so there's reference here for the UK side of things: in theory, and this may not be true of old or modified buildings, each ring main is good for 32A. You may therefore draw up to 32A, or just over 7.5KW, in total, with no 13A connector carrying more than 3KW. It is not always easy or possible to tell which outlets are on which ring, but across two separate levels of a building you're pretty safe to assume they're different. High-capacity items like cookers and water heaters are generally wired in directly and there's generally no opportunity to use those higher capacity circuits without cutting and stripping, which I wouldn't encourage. I can't think that anyone would go to the consumer unit (fusebox) and try to get in there. Domestic homes in the UK are generally on a single phase and there is no load balancing issue, or at least not one that you can do anything about.

 

The only situation where you might do otherwise is in an industrial building which might have three-phase power. Just to make it absolutely clear, three phase in the UK is 415 volts and if you go across that you will most certainly die. It may under some very extreme circumstances, if you are working in a particularly ill-prepared studio, be necessary to connect to busbars in a (usually locked) cabinet, but I'm not sure what the procedure or rules are for that, and if you don't know either, you aren't qualified to do it.

 

The standard mains connector for both stage, concert, film/TV and other work in the UK looks like this:

 

 

Left to right: 63A single phase, neutral and earth, ditto 16A and two variations on 32A. Blue indicates single phase.

 

 

Left to right: 63A 3-phase neutral and earth, ditto 32A, ditto 16A. Red indicates three phase.

 

Other variations include white (low voltage AC), green (High voltage, high frequency, often seen on naval vessels and aircraft which use turboalternators) and purple (can't remember.)

 

The connector is generally referred to as a Ceeform and is to specification BS4343, being splashproof but not waterproof.

 

Here endeth the Phil Rhodes geek guide to UK mains distribution. Those connectors come in varieties up to 125A. I saw one that had melted last week - loose neutral - which was pretty spectacular!

 

Phil

[John Sprung]

Domestic homes in the UK are generally on a single phase and there is no load balancing issue, or at least not one that you can do anything about.

<{POST_SNAPBACK}>

Very interesting. A friend in the Netherlands told me that they all have three phase at home. Here in L.A., the DWP refuses to sell three phase to residential customers, even if they have it available on the poles for neighboring commercial users. Too bad, it would be nice for the HVAC guys. Here we have 120/240 volt center tap single phase, so balancing and having a good neutral are considerations. It's surprising how many different ways there are to do basically the same thing.

 

 

 

-- J.S.