I'm doing work on a high end custom home for a architectural firm. This project has been in planning for the last 2 years. They had originally spec'd the service for 3 phase until the power company informed them they would not provide 3 phase to a residence. I suspect the panel schedule they provided was meant for the 3 phase system.
When I tried to obtain a quote from my Vendor for a Siemans Panel (see specs below) they said it exceeded the 10% rule and that they would not be able to provide the panel. Has anyone ever heard of this rule before? I did find in 408.13 (b) (2002 NEC) a rule regarding panel board protection.... Not sure if this is what they were referring to. Any feedback or guidance would be appreciated.
800 AMP Panel, 60 Spaces, Single Phase 120/240v, 42 KAIC Circuit Details: 24 - 20AMP Single Poles 1 - 30AMP Double Pole 1 - 200AMP Double Pole (sub Panel) 1 - 225AMP Double Pole (Sub Panel) 1 - 100AMP Double Pole (Sub Panel) 1 - 400 AMP Double Pole (ATS for Generator) 2 - 80 AMP Double Poles 1 - 60 AMP Sauna
You need to go to 408.14 and 408.15 for the answer. A lighting and appliance panelboard is one with more than 10% of it's overcurrent devices 30 Amps or less, and the branch circuits connected to neutral.
It's only allowed 42 circuits (which you have)
They don't want to sell you a 60 space power panel.
I just recounted the circuits in this panel (I missed a few on my earlier post) and the total is 44. So does this mean this would NOT be allowed? I really don't think my vendor doesn't want to sell me a 60 space panel. I guess I'm still not clear on this. I should also mention 2 other sub panels contain more than 42 circuits (one has 46 and the other has 54)
Would it be incorrect to inform the architect his panel schedules are not to code (i.e., 408.15)?
Maybe you should consider a main "power distribution" panel that contains the only the main breakers for a couple more subs. Although '08 will allow you more circuits, '08 is not active yet and a lot of municipalities won't adopt it right away anyway.
Like I said above, you need to read 408.14 and 408.15 for your answer. The answer is right there in black and white. Your vendor might "like" to sell you a 60 space panel, but cannot. Your single pole breakers alone add up to more than 10% of the total, and therefore, will not comply with the Code if they are in 1 enclosure. Like Greg said, the '08 NEC will do away with the 42 circuit rule, but until it is adopted in your area, you are out of luck. ( I notice that your reference came from the'02 NEC).
The ONLY way that you will be able to comply will be to mount multiple panels as the Code requires. You can still have your power panel for the larger C/B's, but will need to have additional panels.
Did the architectural firm give you enough room to do so?