200 amp Service in Condo. building

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Lineman1123

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Boston, MA
So i got a job,

the building is 6 condo units (not very big at all 2bedroom apartments bassically)
each apartment has a 60 amp panel located in the apartment.
My customer wants to put in a 100amp panel.
I looked everywhere in the code and online and i can't find the answer.
I swallowed my ego and asked the inspector of the town and his smart-alec remark was.... look it up in the code book and hung up.

So question is....
in a 200 amp service can you put a 100 amp panel where there is already 5 60 amp panels and a common.

and just for my knowledge, how many 100 amp panels can you put on 200amp service ?

thanks for the help if you guys can it would help me out greatly.
 
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Lineman1123 said:
So i got a job,

the building is 6 condo units (not very big at all 2bedroom apartments bassically)
each apartment has a 60 amp panel located in the apartment.
My customer wants to put in a 100amp panel.
I looked everywhere in the code and online and i can't find the answer.
I swallowed my ego and asked the inspector of the town and his smart ass remark was.... look it up in the code book and hung up.

So question is....
in a 200 amp service can you put a 100 amp panel where there is already 5 60 amp panels and a common.

and just for my knowledge, how many 100 amp panels can you put on 200amp service ?

thanks for the help if you guys can it would help me out greatly.
Click to expand...

What is the 100A for?
You would need to do a load calculation to determine total load and see if you can add more.
 
You could put 200amp panels in each apartment if you really wanted to, as long as the main service calc comes out under 200amps. Usually there is no benefit to going to 100amps in an apartment unless they are adding a bunch of load. Are they adding ACs or an electric range or something? Why do they want to upgrade them?
 
MNSparky said:
You could put 200amp panels in each apartment if you really wanted to, as long as the main service calc comes out under 200amps. Usually there is no benefit to going to 100amps in an apartment unless they are adding a bunch of load. Are they adding ACs or an electric range or something? Why do they want to upgrade them?
Click to expand...

Yes.

Could even have 200 amp panels in apartments and a 100 amp main service disconnect if load calculation is 100 amp or less.
 
hbiss said:
WHY? And what's there now?

-Hal
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Presumably 60 amp feed. Why they want 100? They may not have any real reason other than they think that is better.

I've had customers supply their own 200 amp main breaker panel for a garage that could easily be supplied by a 60 amp feeder, or even a 20 amp MWBC. I also had customers supply their own 100 amp main breaker panel for an attic space being made into a bedroom, and I end up just running two or three circuits (depending on loads, no heat or a/c, might only be one circuit) to their existing panel.
 
kwired said:
Presumably 60 amp feed. Why they want 100? They may not have any real reason other than they think that is better.

I've had customers supply their own 200 amp main breaker panel for a garage that could easily be supplied by a 60 amp feeder, or even a 20 amp MWBC. I also had customers supply their own 100 amp main breaker panel for an attic space being made into a bedroom, and I end up just running two or three circuits (depending on loads, no heat or a/c, might only be one circuit) to their existing panel.
Click to expand...

Yes, I've encountered this as well. People think bigger is better or it will "give them more power", as in they will be able to run more off their existing circuits. Unless they are adding load, "bigger" is just more expensive.

After explaining this to them and clearing my conscious, I will still gladly run 200amps out to their garage if they want to pay the bill! :thumbsup:
 
OP, basically it's no different than a panel where the sum of the branch breakers adds up to a lot more than the panel or feeder rating. It all comes down to the load calc. If you have multiple service disconnects tapped from a single set of service conductors, see 230.90(A) ex 3 which allows the sum of the service disconnects to exceed the rating of the common conductors. Not sure if you have a single main or not
 
electrofelon said:
OP, basically it's no different than a panel where the sum of the branch breakers adds up to a lot more than the panel or feeder rating.
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Agreed. If you think about it, this points out why installing a feeder and sub-panel can be so much more efficient than running individual circuits. Each circuit must be sized for its maximum load, but the feeder need only carry an actual aggregate current.
 
LarryFine said:
Agreed. If you think about it, this points out why installing a feeder and sub-panel can be so much more efficient than running individual circuits. Each circuit must be sized for its maximum load, but the feeder need only carry an actual aggregate current.
Click to expand...


But a feeder to supply just a small number of light duty circuits isn't necessarily worth the effort either, unless maybe the run is fairly long.
 
kwired said:
But a feeder to supply just a small number of light duty circuits isn't necessarily worth the effort either, unless maybe the run is fairly long.
Click to expand...
Agreed. That's why I said "can be" more efficient.

Example: a 100a feeder can supply a lot more than ten 20a circuits.
 
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