The NEC requires that branch circuits be sized to serve 125% of the continuous load and 100% of the noncontinuous load (NEC 210.20(A)). Design Master Electrical includes an option to calculate the branch circuit load at 125% of both the continuous and noncontinuous. This is a more conservative approach than what the NEC requires. You can change this setting using the Size breakers to 100% of noncontinuous load setting in the Circuits, Load Types, and Wire Sizes section of the Options command.

The load types are broken down between continuous and noncontinuous as follows:

Continuous

• Lighting
• Motors (NEC 430.24)
  • Largest Motor
  • Other Motors
  • Cooling, Largest Motor
  • Cooling, Other Motors
  • Heating and Cooling Motor
  • Appliance Motor
• Continuous
• Heating (NEC 424.4(B))
• Appliance, Continuous

Noncontinuous

• Receptacles (NEC Handbook Exhibit 220.4)
• Noncontinuous
• Kitchen
• Diverse
• Small Appliance
• Laundry
• Appliance, Noncontinuous
• Electric Dryer
• Electric Cooking
• Marina / Mobile Home / RV

When you create a custom load type, you specify whether it should be treated as a continuous or noncontinuous load for branch circuit sizing. Do this using the Custom Load Type: Load Type setting in the Circuits, Load Types, and Wire Sizes section of the Options command.

All motors are considered continuous at the branch circuit level.