Question on Load Calculation

[TwittyJ53]

Whole Home Service Load is 195A. But when calculating the load panel by panel individually we have a total load of 209A. (1) 200A Main Panel, (1) 50A Sub Panel, (1) 100A Sub Panel.

200A Main Has total load of 154A
50A Sub Panel Has total load of 17A
100A Sub Panel Has total load of 38A

Confused as to why the AHJ is calculating them individually even though they are all under their individual max load. Can anyone give me a direction to go here? It is much appreciated!

 

[suemarkp]

Calculations get more diversity factors or other factors as they have more load and more items. It should not be unexpected that a service calc come to 195A but yet adding up loads only by panel is higher. Just as adding up all the breakers in a panel comecto a higher value than the panel calc.

The main panel is serving all loads, so the proper calculation is to do it by calculating everything connected to all panels. The calculations for the subpanels is only to determine their minimum feeder size.

Calculating just what is directly connected to the main panel and adding feeder values for the sub panels is not correct. Take it to the extreme and make every loan in the main panel a separate feeder. The main would be grossly oversized in that case because you would most likely never exceed the 10 kva threshold where a 40% load factor gets applied.