minimum service capacity

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jnsh2

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is there a minimum service capacity for individual apartments in a multi-family building. There are 16 apartments and a 600 amp main service disconnect. The apartments currently have 60 amp disconnects. I think 100 amp should be minimum.
 
Re: minimum service capacity

230.79(C) and 230.79(D)

(C) is for one family dwellings and is 100 amps.

(D) is for all others and is 60 amps.
 
Re: minimum service capacity

As Sam points out, 60 amps is correct (NEC minimum) for your situation.

Roger
 
Re: minimum service capacity

just wondering dont you have to compute your load before you state that a 60a disconect is ok as your minimum per 230.79?
 
Re: minimum service capacity

Yes. 230.79(C) & (D) are the minimum allowable.

Edit: You still have to use Article 220 for load calculation. Read 230.79.

If your calculation is 40 amps 230.79(D) says that you still have to use a 60 amp.

If it's 100 amps you'll have to use a 100 amp, not less.

[ March 24, 2005, 10:41 PM: Message edited by: physis ]
 
Re: minimum service capacity

Maybe I'm seeing this wrong, but the OP says the building has a 600 amp main service disconnect outside. The apartment panels are sub-panels. 230.79 is for service disconnecting means. I don't see how it applies to these. I think the NEC minimum size would be whatever the calculated load is.
 
Re: minimum service capacity

You're right eprice. They may not be service panels and if they're not then 230.79 doesn't apply.
 
Re: minimum service capacity

They may not be service panels and if they're not then 230.79 doesn't apply.
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Yes but 230.79 does say that the disconnect feeding these "sub panels" will but no less than 60 amps and since the disconnect is also your service OCPD (230.90/91) it will also be at 60 amps 408.16 will require the panel board to be rated at least 60 amps. :D
 
Re: minimum service capacity

Both Ohio and Pennsylvania require a minimum of 100 amps for an apartment. Most other states have the same requirement.

NEC does not address this as there are still rooming houses where an apartment can be on a 20, 40, or 50 amp line treating the apartment as a glorified recreational vehicle.

However, if a dwelling has say 3 bedrooms, central air, an electric range, and an electric dryer a 100 amp service is going to spot weld the wires to the lugs if the electrician did not use the silicon carbide paper - elbow grease - electrical grease method on the wire strands. Dr Jesse Aronstein www.inspect-ny.com ran some tests for the Consumer Product Safety Commission which showed that a wire brush is 100% INEFFECTIVE at removing aluminum oxide. My experience is that thanks to catalytic converters copper oxidizes just as fast as aluminum.
 
Re: minimum service capacity

If a metering center has a service switch and overcurrent protection ahead of the meters then the meter and line for each apartment is a feeder which does not need to meet a 60 amp or 100 amp minimum like with a service as far as NEC is concerned.
 
Re: minimum service capacity

By Mc5w If a metering center has a service switch and overcurrent protection ahead of the meters then the meter and line for each apartment is a feeder which does not need to meet a 60 amp or 100 amp minimum like with a service as far as NEC is concerned.
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Then you would have to follow 240.21(B)(1)
Which it think you would find imposable unless all the apartment are very very close to one another? :D

And that 408.16 does not go away as you will still need an OCPD rated for the panel. :D

[ March 27, 2005, 01:11 AM: Message edited by: hurk27 ]
 
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