The Electrical Code

220.18 Maximum Loads. Here we have motors and how they want us to calculate how big the wire needs to be when we add it all together. “A” says 125% of the largest motor. So 1.25 times the amp on the description plate of the motor. “B” suggest that we don’t calculate the watts of the bulbs but the total watts the LED drivers can handle just in case we continue adding lights to the driver. I think that makes sense. I hope that makes. “C” refers to ranges and in the table it says the number of appliances, give us a demand factor.

“The total load shall not exceed the rating of the branch circuit, and it shall not exceed the maximum loads specified in 220.18(A) through (C) under the conditions specified therein.

(A) Motor-Operated and Combination Loads. Where a circuit supplies only motor-operated loads, Article 430 shall apply. Where a circuit supplies only air-conditioning equipment, refrigerating equipment, or both, Article 440 shall apply. For circuits supplying loads consisting of motor-operated utilization equipment that is fastened in place and has a motor larger than 1∕8 hp in combination with other loads, the total calculated load shall be based on 125 percent of the largest motor load plus the sum of the other loads.

(B) Inductive and LED Lighting Loads. For circuits supplying lighting units that have ballasts, transformers, autotransformers, or LED drivers, the calculated load shall be based on the total ampere ratings of such units and not on the total watts of the lamps.

(C) Range Loads. It shall be permissible to apply demand factors for range loads in accordance with Table 220.55, including Note 4.”