Code Change Summary: Revised code section on appliance demand factors.
NEC Section 220.53 provides a 75% derating allowance for four or more fastened in place appliances supplied by the same feeder or service in a one-family, two-family, or multifamily dwelling. The previous code language was a bit cumbersome but has been cleaned up in the 2020 NEC® and formatted into a list of items that the 75% demand factor does not apply to.
In addition, the demand factor now only applies to appliances rated no less than ¼ HP or 500 watts. This new language helps to rule out small equipment like bathroom exhaust fans and most ceiling fans which are already included in the general lighting load.
Examples of appliances that the demand factor may apply to include:
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2020 NEC® edition of NFPA 70.
2017 Code Language:
220.53 Appliance Load — Dwelling Unit(s). It shall be permissible to apply a demand factor of 75 percent to the nameplate rating load of four or more appliances fastened in place, other than electric ranges, clothes dryers, space-heating equipment, or air-conditioning equipment, that are served by the same feeder or service in a one-family, two-family, or multifamily dwelling.
2020 Code Language:
220.53 Appliance Load — Dwelling Unit(s). It shall be permissible to apply a demand factor of 75 percent to the nameplate rating load of four or more appliances rated 1∕ 4 hp or greater, or 500 watts or greater, that are fastened in place, and that are served by the same feeder or service in a one-family, two-family, or multifamily dwelling. This demand factor shall not apply to:
(1) Household electric cooking equipment that is fastened in place
(2) Clothes dryers
(3) Space heating equipment
(4) Air-conditioning equipment.
Refer to the image of the kitchen waste disposer:
Based on the revised code language which of the following is true?
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