Up to the point that the original poster said something about running a
large lighting load plus AC units it sounded like a pretty standard (and
more than adequate) installation for a domestic/home garage. Total
capability (provided that wire is heavy enough) for say 15,000 to 16,000
watts, with perhaps some concerns about the starting currents of various
motors? In one manner it wouldn't matter if those watts are 110 or 220 volt
provided they are distributed within the capabilities of the individual
circuits, and the total safe load not exceeded.
I would have no trouble, as I do in my own garage running some lighting the
occasional couple of kilowatt heater (it's cooler here!) and a few tools;
in such an installation! probably including a 5 HP (220 volt) air
But this isn't just a garage it's some kind of (film?) studio?
That is; is it a business; which is being sub-fed from the main panel of a
residence? Maybe should have had its own service?
So I respectfully suggest that whoever made up the original specification
erred when specifying a 'garage'?
Rather like saying "Need vehicle to take some people to location 'xyz'". And
then when a standard taxi capable of say four passengers arrives,
exclaiming, "Oh but I've got a hockey team with 12 players and 2 coaches"!
And finding it needs at least a stretch limousine or small bus?
By the way what are the local municipality rules for operating a commercial
enterprise in, or associated with, a residence? We had a problem with
someone who was welding in his 'home' work shop. It was later determined he
was operating a business and the town council ordered him to desist!
Taking a guess at what 'some' home studios are used for; be a pity if the
lights go out just when a 'climax' was being reached, because the electrical
requirement was incorrectly specified before the start. Haven't seen
anything yet that suggest electrician did anything not normal or standard?
BTW high electrical consumption (even when people have tried to 'cheat' the
meter) has, here given away quite a few 'grow ops'!
When the home was purchased (not custom), the exterior garage/workshops
was offered as an option. When you ordered one of the optional
builings, your service box on your house was automatically upgraded
from a 200 service box to a 400 service. Another option that was
offered was toadd 220 60 amp in the structure, we odered two of the 220
60 amp options.
So, 1) I would have thought If they were upgrading the home service
from 200 to 400, the would have then installed a 200 on the exterior
2) If they saw there were two 220 60amp options purchased they would
have planned what the needed requirements would be and if there was a
red flag, contact the builder and inform them of the situation.
Additionally in the builders contract under electrical options it is
stated "Electrical Options for detached structure will be reviewed by
electrcal contractor. There may be additional costs to the buyer due to
the number of electrical options selected". If this was out of the norm
and needed a larger service box or larger guage wire, it should have
A rep from electrical contractor was out today, and he admitted there
was mistake but wouldn't admit who should be at fault, the sales guy,
who took the order, the electrical contractor, or the builder.
Basically he said it wasn't caught because the garage was speced to
them to use a 100 service box, so one guy installs the box, one does
the rough in, one guy, does the final wiring, and no one looked at the
whole picture or questioned the amount of amps or there usage. So they
are now sitting down with the builder and figure who is at fault and
who will pay the extra expense to correct.
As far as other questions and comments:
1) We tried to get a seperate service meter to the building, power
company couldn't do that.
2) As far as business run from home, these homes are all on 1 or 2 acre
lots, a # of people are running smal business from the home or back
yard structure. The main thing is you don't have a traffic of customers
or a parking situation, which we don't.
3) The type of videos we produce are 1) a talk show on natural health
care geared towards chiropractors and 2)DVD's aimed at offroading and
[Oops, should have read this first]
Stan was right on. This is not a garage, it is a video production
studio You don't seem to have told the electricians what you wanted...
you just sort of quietly implied it by ordering some extra breakers for
your "garage" and expecting them to figure out that this is not a
residential garage at all, but something very different. The whole mess
could have been avoided very easily by just telling them upfront that
you need 200+ A in the separate building because you are not going to
be using it as a garage.
And, I don't understand about "the power company couldn't do that". Are
you trying to say that you explained the situation... "I am building a
video productoin studio on my property, can I create a separate new
account for this business and get a separate service entrance for a
separate building?" (of course the answer would probably be "dude, this
is _so_ not zoned for that")
Or is it more like "Well, do you think you could put a second service
drop to my, ahem, garage?" to which the answer is "no".
So you really just have to put in new wires. If you have 400A at the
house, go ahead and put in 200 or more to the studio. Otherwise you
will need to upgrade the house drop too.
about the only way to find out the wire size is to measure the actual
conductor size where the wire is stripped so you're not measuring the
insulation at all. You would need to use a caliper to get this reasonably
You would do this at the branch panel when you are very sure the feed
breaker is off (double check with a meter).
When this is known, the wire gage can be looked up in a number of places, or
post the info here.
Then the ampacity of the copper or aluminum conductor can be determined.
You would then at least know if the circuit is safe as far as the breaker
size at the main panel.
Did you specify to your electrical contractor what your loads were going to
be? From what you describe a 100 amp panel may be marginal at best. A 100
amp panel is only good for 80 amps continuous load (3 hours or more). I
have wired a number of TV and photo studios and I would have put in at least
a 200 amp panel based on your load schedule. Not every electrician is
familiar your type of operation. Your electrician may have sized it like a
home, but I know that once the hot lights are on, those A/C units will be
running continuously. Also, I would have installed three electrical
panels; one for the electronics, one for lighting, and one for the
mechanical equipment. It is best to have all of the electronic equipment
come out of the same panel to keep ground hum to a minimum. Keep your
dimmer racks away from all other equipment and out of the shooting area if
possible. It's best if they are in their own air conditioned room or
If the wire is in conduit, it may be possible to pull in a larger size if
the pipe is a little oversized. Use copper wire.
I'm wondering if your A/C units will be big enough to handle the heat load.
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