Disconnect for apartment meter center

[frostback]

If i have an optional code calc of say 350 amps
on a 120/208v 3p-4w meter center is a 400 amp
switch or cb adequate for protection or do i
have to further demand that load by 1.2 for article 220-4(a)

 

[bphgravity]

Re: Disconnect for apartment meter center

I am confused by your question as I am not aware of a demand factor of 1.2 anywhere in Article 220 let alone 220.4?

When performing an optional calculation, you need only to follow the requirements of that section and are not required to include any loads specified by the standard method.

 

[frostback]

Re: Disconnect for apartment meter center

Sorry for the confusion.
Are you saying that because of the optional calculation for dwelling units, a load of any ampacity up to 399amps in a modular meter center
can be ,by code, protected by a 400amp switch or cb?

 

[haskindm]

Re: Disconnect for apartment meter center

Absolutely. In fact a 400-amp calculated load could use a 400-amp switch. We only need to provide ampacity for the load as calculated using article 220. There seems to be a myth that no switch or circuit breaker should ever be loaded to more than 80% of it's capacity. The code does not say that, it only says that a continuous load cannot be more than 80% of the rated capacity.