continuous loads for residence

[dhsvcs]

I have a job where there will be at least 3 sub-panels being fed from a 400-320 amp 240 v 1 phase meter center. It has a G.E. meter assembly with a 200 A breaker feeding a 8 circuit load center with bottom lugs for feed through and an empty space for a 2nd breaker not yet installed with a conduit chase to feed future loads.

So far, the loads calculate out to 180 amps to 2 load centers using using optional load calculations, 220 A standard calculations. There will be future loads such as swimming pool and car chargers coming p on next revision, which is why we chose 400 / 320 A meter center.

I understand that the entire service can utilize the optional load calc for a total load, but I am wondering if there is a list of items that is considered a continuous load that must be calculated at 125% continuous load, and since eventually there will be at least 3-4 load centers fed by the 2 200 A breakers,
must all panel feeds need to be calculated at 100% and 125% depending on whether they are continuous loads ?
thanx, dhsvcs

 

[augie47]

For feeders the 1st thing I thing of is 625.41

 

[Little Bill]

Only continuous loads require the 125%, not the feeds. Fixed electric heating is the most common item in a dwelling that might be a continuous load.


ETA: That was until the EV charging came about!

 

[kwired]

Only continuous loads require the 125%, not the feeds. Fixed electric heating is the most common item in a dwelling that might be a continuous load.


ETA: That was until the EV charging came about!

There are other items that may require 125% for continuous loads but for branch circuit calculations. For feeder and service calculations some those items may be permitted to have demand factors applied to them.

 

[dhsvcs]

If there are multiple panels fed from the service, what are the demand factors that are allowed for individual panels ?
There is 1 meter can feeding 3 sub-panels. I know I can derate the entire service, but what is allowed for individual panels ?
This is for a 400 A continuous / 320 A residential service...

 

[dhsvcs]

Are there demand factors that i can use individually for each panel ?

 

[kwired]

If there are multiple panels fed from the service, what are the demand factors that are allowed for individual panels ?
There is 1 meter can feeding 3 sub-panels. I know I can derate the entire service, but what is allowed for individual panels ?
This is for a 400 A continuous / 320 A residential service...

You would have to calculate each feeder individually.

A demand factor that can apply to the service may not necessarily be able to be applied to a feeder that doesn't carry same load as the service.
One example: Say you had three kitchen areas and three ranges/cooking appliances (not over 12kW) each on different feeder. The allowed demand factor for those would be 14kW for the service or a feeder that supplies all three, but the demand factor for each individual feeder calculation with only one appliance you have to use 8 kW.

Similar can apply for other allowed demand factors