Is this panel overloaded?

[david luchini]

The OP did say "200 amp main breaker with a calculated load of 179 amps". Why assume that there's a problem with the calculation?

I don't assume that there is a problem with the calculation. I am simply saying that the information doesn't tell us everything we need to know to answer the question.

Don't the words calculated load imply that both continuos and non-continuos loads have been considered or are we working from a new definition in this thread?

Yes, the words calculated load imply that both continuous and non-continuous loads are being considered: calculated load = continuous loads + non-continuous loads. The calculated load (per 220.40) is the sum of the loads on the branch circuits (as determined by Part II of Art. 220) after any applicable demand factors have been applied.

If you had a 3000 sf office building with 50 receptacles outlets, 220.40 would tell you your calculated load would be:
Lighting 3.5va/sf*3000sf = 10500va (continuous)
Receptacle 180va @ 50 = 9000va (non-continuous)
Total 19500va

 

[infinity]

I'm not trying to harp on the obvious but the question is rather simple, is a calculated load of 179 amps permitted to on a panel with a 200 amp main breaker? The answer is yes, unless we're rewriting the definition of calculated load.

 

[qcroanoke]

I'm not trying to harp on the obvious but the question is rather simple, is a calculated load of 179 amps permitted to on a panel with a 200 amp main breaker? The answer is yes, unless we're rewriting the definition of calculated load.

That really is all I was asking.
Thanks for all the replies!

 

[david luchini]

I'm not trying to harp on the obvious but the question is rather simple, is a calculated load of 179 amps permitted to on a panel with a 200 amp main breaker? The answer is yes, unless we're rewriting the definition of calculated load.

This simply isn't true, unless you are rewriting the definition of calculated load.

Read 220.40 again. If the loads from my branch circuits are 10500va lighting and 9000va receptacles, then my calculated load is 19500va, per 220.40.

If this load was on a 208V, 3ph feeder, the load current would be 54.1Amps. If I had this load on a panel with a 60A main breaker, would it be overloaded? (Or undersized as kingpb puts it?)

 

[Smart $]

I'm not trying to harp on the obvious but the question is rather simple, is a calculated load of 179 amps permitted to on a panel with a 200 amp main breaker? The answer is yes, unless we're rewriting the definition of calculated load.

The answer is maybe, maybe not. When someone says the "calculated load", it does not necessarily mean it is the minimum required feeder ampacity for the loads, which is what determines minimum panel rating. That is, calculated load by itself, does not mean the 125% factoring of continuous loads has been considered in the value given. The statement effectively must say "the minimum calculated feeder ampacity" before we can be certain.

Below is Example D3 in its entirety:

Note the Calculated Load is not the same as the Minimum Size Feeders Required, which has the same value as the minimum panel rating per 408.30.

 

[david luchini]

That is, calculated load by itself, does not mean the 125% factoring of continuous loads has been considered in the value given.

That is precisely the point I've been trying to make. The method for calculating the load on a feeder is given in 220.40.

The only place 125% shows up in 220.40 (or by extension, Parts III, IV & V of 220) is in 220.87 for determining existing loads and in 220.102. There is nothing about continuous and non-continuous load.

The calculated load is the sum of the loads on the branch circuits, after any permissible demand factors have been applied. Continuous/Non-continuous is not factored into "calculated load."

 

[Sierrasparky]

as long as properly calculated it's ok.

 

[Smart $]

as long as properly calculated it's ok.

...and as Besoeker would say, "That's all there is to it!"

:lol: