Optional Multi Family Service Calculations

Ampacity Correction
Temperature Correction
Continuous Load Correction
Conduit Fill Correction
Minimum Number of Circuits
Bus Bar Ampacity
Conductor Resistance
Resistance Change
Motor Disconnect Sizing
Full Load Current Interpolation
Motor Conductor Sizing
Motor Overcurrent Protection
Motor Overload Sizing
Lighting Loads
Fixed Appliance Loads
Range Loads
Range Loads Note 1
Range Loads Note 2
Dryer Water Heater Loads
Heat AC
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This calculation is the workhorse for all multi-family dwelling units. NEC 220.84 gives the technique repeated here:

Determine the total connected load then multiply by the demand factor as given in table 220.84

Total connected load is computed as follows:

1. 3va per square foot.
2. 1500va for each small appliance circuit and each laundry circuit.
3.nameplate of everything else except heat and ac.
4. larger of heat or ac.

Multiply this total by the demand factor from the table mentioned above.

Divide by voltage of the service and divide by 1.732 if the service is to be three phase.

That's it. You're done.

It's so simple I don't have practice problems for this calculation.



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