panel load calcs...

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mayjong

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residential-05 NEC
customer wants to add a 60A sub to a 200A panel. 200A already has 2 @ 125A subs and 2@ 30A breakers.
do i require load calcs?
thanks!
 
mayjong said:
residential-05 NEC
customer wants to add a 60A sub to a 200A panel. 200A already has 2 @ 125A subs and 2@ 30A breakers.
do i require load calcs?
thanks!
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Yes, the contractor has to comply with 215.2, 225.3, 230.31, & 408.30 as a minimum. This is something the contractor should care about more than you.

Great question in this case! At least ask the contractor if they are in compliance with these sections
 
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ya, i guess i can just ask. the problem is they/he would have to calc the whole thing. (which they won't do, at least correctly)
they are only installing 1 20A circuit for lights, plugs. but that leaves alot of open space in the panel.
thanks, you answered my question, basically not much i can do about it!
 
You would probably be surprised at how little load is actually on that panel if they did a load calc. I have one that's designed for added loads and many a 200 amp panel comes back at less than 100 amps being used, but from time to time I'll get 100 amp panel that calcs out at 102+ amps.

While I agree that they have to potential of overloading the main simply because they have all those subpanels and there for all those spaces that they could use, I've learned my lesson on this forum, you can't inspect for the future.
 
mayjong said:
ya, i guess i can just ask. the problem is they/he would have to calc the whole thing. (which they won't do, at least correctly)
they are only installing 1 20A circuit for lights, plugs. but that leaves alot of open space in the panel.
thanks, you answered my question, basically not much i can do about it!
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Why would anyone add a sub panel that uses 2 spaces to add a 1 space circuit ? He admits to adding a load but that load would not count. I suspect he is up to something. Legaly he adds nothing to load calc but then why the sub panel. Your being had big time. Would make note on the paper work / permit that it is passed for purpose of that 1 circuit.
 
Jim W in Tampa said:
Why would anyone add a sub panel that uses 2 spaces to add a 1 space circuit ? He admits to adding a load but that load would not count. I suspect he is up to something. Legaly he adds nothing to load calc but then why the sub panel. Your being had big time. Would make note on the paper work / permit that it is passed for purpose of that 1 circuit.
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Ha! That would almost be funny if someone wasn't up to shenanagins. Like drilling a hole in the bottom of the boat to let the water out....
 
Jim W in Tampa said:
Why would anyone add a sub panel that uses 2 spaces to add a 1 space circuit ? He admits to adding a load but that load would not count. I suspect he is up to something. Legally he adds nothing to load calc but then why the sub panel. Your being had big time. Would make note on the paper work / permit that it is passed for purpose of that 1 circuit.
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Jim, no matter what you think of us, you would make a good inspector. :smile: That's the problem, we probably all know that there's more to this than we're being told. What's funny though is that they'll get the permit to put in the subpanel just so they can hook something up to it illegally later.
 
cowboyjwc said:
would What's funny though is that they'll get the permit to put in the subpanel just so they can hook something up to it illegally later.
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my thought, too...
i was trying to find a way (calcs?) to put it over 200A and not allow it. i'll make a note and move on...
 
mayjong said:
my thought, too...
i was trying to find a way (calcs?) to put it over 200A and not allow it. i'll make a note and move on...
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Chances are the load they have now will pass with 200 amps. Takes a mighty big house to max that out. Now just maybe that 60 is for a hot tub or welder that might put it over the limit. Does seem strange that they pulled a permit for what is very clear something they intend to add soon as ink dries. But little you can do but sign off.
 
cowboyjwc said:
Jim, no matter what you think of us, you would make a good inspector. :smile: That's the problem, we probably all know that there's more to this than we're being told. What's funny though is that they'll get the permit to put in the subpanel just so they can hook something up to it illegally later.
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I gave thought to it few times but would not care to put up with all you inspectors go thru. LOL
I am sure he will watch this mans work in future and not trust him for his word in future, i sure wouldn't.
 
cowboyjwc said:
You would probably be surprised at how little load is actually on that panel if they did a load calc. I have one that's designed for added loads and many a 200 amp panel comes back at less than 100 amps being used, but from time to time I'll get 100 amp panel that calcs out at 102+ amps.

While I agree that they have to potential of overloading the main simply because they have all those subpanels and there for all those spaces that they could use, I've learned my lesson on this forum, you can't inspect for the future.
Click to expand...

What would be the worse thing that could happen if they exceeded the current rating of the main breaker? loss of power? now they have to call an electrical contractor to upgrade the service, more work for the contractor seems like a good thing to me. just adding extra spaces IMO shouldn't be a problem. Didn't they remove the number of spaces allowed in a panel box for the 2008 code, so now you're not limited to the 42. Now that I read this forum I stay confused all the time :confused:
 
neutral said:
What would be the worse thing that could happen if they exceeded the current rating of the main breaker? loss of power? now they have to call an electrical contractor to upgrade the service, more work for the contractor seems like a good thing to me. just adding extra spaces IMO shouldn't be a problem. Didn't they remove the number of spaces allowed in a panel box for the 2008 code, so now you're not limited to the 42. Now that I read this forum I stay confused all the time :confused:
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No problem with you having a panel with 40 plus spaces and only a few used. Not much an inspector could or would say. But if you then add a sub panel and say its for 1 lighting circuit your simply playing a game. See this all the time, nothing but warehouse with few lights and get CO then build out unit with no permits or inspections.
 
neutral said:
What would be the worse thing that could happen if they exceeded the current rating of the main breaker? loss of power? now they have to call an electrical contractor to upgrade the service, more work for the contractor seems like a good thing to me. just adding extra spaces IMO shouldn't be a problem. Didn't they remove the number of spaces allowed in a panel box for the 2008 code, so now you're not limited to the 42. Now that I read this forum I stay confused all the time :confused:
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Look, I know as well as the next guy that he could have 100 breakers and at no point during the day be pulling more than 50 amps, but I also know that he could have 10 breakers and be pulling every bit of the 200 amps he has. The amount of spaces doesn't really have as much to do with it as the why does he need all those spaces?

I had a guy come in for a plan check and I asked for a load calc. He called me a few days later and said that he had never been asked for one before, especially since he was only building a detached garage. At first I couldn't remember what he was talking about then it hit me, I said is this the 2500 sq ft garage with the car lift and the six 60 amp outlets and all the lights and the two A/C.s? Yeah. Load calc. Funny his 200 amp panel with the garage came out to 210 amps.

As a contractor you can say, "I'll put in what ever the HO will pay for", as an inspector you have to look at it as, "if it doesn't seem right it's probably not."
 
Jim W in Tampa said:
No problem with you having a panel with 40 plus spaces and only a few used. Not much an inspector could or would say. But if you then add a sub panel and say its for 1 lighting circuit your simply playing a game. See this all the time, nothing but warehouse with few lights and get CO then build out unit with no permits or inspections.
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That is usually the way it is in commercial spaces. The contractor hired by the landlord for the "shell" may not be the same as the one doing the build-out. Not much you can do even if planned that way. The only choice is to be a cop and drive around looking for violaters.
 
Sierrasparky said:
That is usually the way it is in commercial spaces. The contractor hired by the landlord for the "shell" may not be the same as the one doing the build-out. Not much you can do even if planned that way. The only choice is to be a cop and drive around looking for violaters.
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Recently did a remodel on a 40,000 sq ft office/warehouse. The violations i found left no question as to first buildout was with no permits. Was a real pain as i was required to keep track of time and materials to every code fix as some were paid by landlord,some back charged to last tenant and many extras wanted by new tenant. Inspection went easy all areas to be inspected were up to code. Other areas simply not looked at as not part of our permit.
Simply up to building department to find a way to stop this type of add on unpermited items.
OP leaves little dought that he is trying to pull something. Trouble is in most states the county simply can not enter property without owners ok. You as owner can tell county to get off your property. Even cops must have search warrant or probable cause to believe a crime is going on to demand entry.
 
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