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Table 220.42: Lighting Load Demand Factors

17200 Views 8 Replies 5 Participants Last post by  Gary Arthurs, 
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I teach electrical construction. I have load calculation worksheets for residential service panels. These worksheets are calculated as follows:

The Lighting Load Demand Factor (Table 220.42) is calculated AFTER adding together the General Lighting Load per Table 220.12 and Small Appliance Circuit Load per 220.52(A) and (B).

Article 220.42, however, states: "The demand factors specified in Table 220.42 shall apply to that portion of the total branch circuit load calculated for GENERAL ILLUMINATION. They shall not be applied in determining the number of branch circuits for general illumination."

I interpret "General Illumination" to be the load calculated according to 220.12; not 220.12 plus 220.52. I can not find in the code book where "General Illumination" is defined. According to my load calculation worksheets, "General Illumination" includes the Small Appliance and Laundry Loads (220.52).

I think article 220.42 applies only to 220.12; not 220.12 plus 220.52.

Any suggestions or comments?
Thank you.
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Barjack
paulgarett said:
I teach electrical construction. I have load calculation worksheets for residential service panels. These worksheets are calculated as follows:

The Lighting Load Demand Factor (Table 220.42) is calculated AFTER adding together the General Lighting Load per Table 220.12 and Small Appliance Circuit Load per 220.52(A) and (B).

Article 220.42, however, states: "The demand factors specified in Table 220.42 shall apply to that portion of the total branch circuit load calculated for GENERAL ILLUMINATION. They shall not be applied in determining the number of branch circuits for general illumination."

I interpret "General Illumination" to be the load calculated according to 220.12; not 220.12 plus 220.52. I can not find in the code book where "General Illumination" is defined. According to my load calculation worksheets, "General Illumination" includes the Small Appliance and Laundry Loads (220.52).

I think article 220.42 applies only to 220.12; not 220.12 plus 220.52.

Any suggestions or comments?
Thank you.
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You are making this more complicated than it needs to be.

You get your lighting load from T.220.12 based on square footage and occupancy type.

Then, you get your SABC load from 210.11C.

Then, you apply the demand factors in T.220.42.

I think you're getting hung up on the fact that T.220.42 says "Lighting Load Demand Factors" but that you are allowed to include SABC's in it.
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