When calculating the NEUTRAL in the Optional residential method- I revert to the Standard method to size the neutral.

Do I reduce the '4 or more 120V fixed appliances' load by 75% ?

My CE text book is excellent but does not reduce the Demand Factor for these when calculating the neutral.

The Annex D examples in the NEC doesn't address this, too few fixed appliances.

Article 220.53, and of course 220.61, both seem like they'd apply, to me.

Hi Finite,

Article 220 can be confusing when calculating the unbalanced appliances unless each Section is adjusted within the method being used. Standard and optional methods are not intermixed as Smart$ mentions, so [220.61] is used for both methods in calculating the neutral size separately.

In using the standard method, the [220.53] 75% load DF is applied to 4 or more FIP Appliances (other than range, cl. dryers, space heating or A/C). The 3 or less FIP will be 100% NPR applied. The total FIP % used will be added to the General, SA, and Laundry subtotals prior to including CL.Dryer [220.54], range[220.55], elec. heat , A/C (omit smaller load if both used) and finally, 25% largest motor before totaling all for the dwelling standard total demand load.

In using the optional method(s), General, SA, and Laundry are totaled with All FIP, specific circuits, motors, etc. [220.82b3], [220.82b4] at the NPR only...before calculating the [220.80b] DF. Heating or A/C are not included here, but separately calculated in the [220.82c] subtotal prior to the final dwelling optional demand load total.

[220.61a] Standard calculation is then used to determine the unbalanced calculated load for the neutral conductor size.

I find this makes the [220] calculations easier to follow when deciding which method is more appropriate in considering a service size capacity with load averaging DF calculations.