225.39(D) - Multi-family residential 240/120 single phase main service replacement

[fandi]

Hi All,
Currently no new loads added for each unit. But if the main service is being replaced MEANING THE EXISTING CONDITION IS BEING ALTERED, does the latest/current code (which is NEC 2014 in California) 225.39(D) kick in? And if the feeder breakers were 60A, then I guess the current 30A feeders have to be upsized to 60A rating also.
Thanks.

 

[charlie b]

The NEC will not answer your question regarding the requirement to upgrade anything, given that the service is being altered. That is up to local authorities.

I would need a clearer notion of the setup, before answering your other question. I gather that there is a service that is common to a number of units. I infer that either the service conductors, or the service equipment, or both, are being replaced. But what is downstream from the main service disconnect? Is this a distribution panel that has separate feeder breakers for each unit? If so, what is the rating of each breaker, and is each feeder only capable of handling 30 amps? If that is the case, I would wonder what is inside each unit. You can't do much with 60 amps, and 30 amps is hardly enough for a small kitchen.

I would agree with what I think you said, in that if you have to replace the feeder breakers with 60 amp breakers, then you would also need to upsize the feeders themselves.

 

[charlie b]

I would also ask for clarification regarding your phrase, "multi-family residential." Do you mean, by NEC definitions, "dwelling, multifamily"? In other words, is each of the units a "dwelling unit" on its own right? If so, would you not be dealing with 225.39(C)?

 

[fandi]

Hi Charlie,
Please see my reply below. So if the existing circuits are being touched, even at the main service and not the sub-panel inside each unit, then the current code apply?

The NEC will not answer your question regarding the requirement to upgrade anything, given that the service is being altered. That is up to local authorities.

I would need a clearer notion of the setup, before answering your other question.
I gather that there is a service that is common to a number of units. [Yes]
I infer that either the service conductors, or the service equipment, or both, are being replaced. [Yes, as a result of the main service being upgraded ]
But what is downstream from the main service disconnect? Is this a distribution panel that has separate feeder breakers for each unit? If so, what is the rating of each breaker, and is each feeder only capable of handling 30 amps? [It's multiple gang meter/breaker combo, each unit s its own 30A meter/breaker, the feeders are only rated at 30A]
If that is the case, I would wonder what is inside each unit. [100A sub-panel but limited to 30A breaker at the meter]
You can't do much with 60 amps, and 30 amps is hardly enough for a small kitchen.

I would agree with what I think you said, in that if you have to replace the feeder breakers with 60 amp breakers, then you would also need to upsize the feeders themselves.

 

[fandi]

I would also ask for clarification regarding your phrase, "multi-family residential." Do you mean, by NEC definitions, "dwelling, multifamily"? In other words, is each of the units a "dwelling unit" on its own right? If so, would you not be dealing with 225.39(C)?

Sorry I meant multi metered property, not multi-family one. The landlord divides one big house into sections and rent it out to different tenants.