Service size calculation

[mshields]

Doing a service size calc and I've got a substantial amount of electric heat (in the form of Terminal Boxes). Because Article 424.3 which is referenced by Table 220.3, states that this is a continuous load, I'm taking this load at 100%.

Is that correct?

Thanks,

Mike

 

[charlie b]

I should think it would have to be counted at 125%, being a continuous load.

 

[Volta]

I think you are both right, for different parts of the calculation.

Section 424.3 is for branch circuits. Sub-section 'B' states that the equipment shall be considered a continuous load- for calculating branch circuits.

Thus, 125% of the nameplate while figuring each and every branch circuit.

Then when calculating feeder and service loads, Section 220.51 allows the load to be calculated at 100%, as long as not smaller than the largest branch circuit.