What is the minimum calculated service load for 19-4,800 watt electric clothes dryers supplied by a 3-phase service?

To determine the minimum calculated service load for 19 electric clothes dryers rated at 4,800 watts each when supplied by a 3-phase service, it's essential to first calculate the total wattage of all dryers combined.

Start by calculating the total load by multiplying the number of dryers by the wattage of each dryer:

19 dryers × 4,800 watts = 91,200 watts.

This total represents the overall wattage that needs to be served. However, when considering a 3-phase system, the load can be adjusted based on the demand factors provided in the National Electrical Code (NEC), which often allows for derating due to the nature of the equipment.

Assuming the use of demand factors (which is common in calculations for appliances like dryers), a reduction in the calculated load may apply as not all dryers will be running at full capacity simultaneously. For instance, NEC guidelines suggest applying demand factors for household cooking and clothes drying equipment, which could allow for adjustments on the calculated load.

In this case, the total load of 91,200 watts can be simplified to kilowatts by dividing by 1,000, leading to 91.2 kW. When applying the proper demand factors, the sum can