Question on Multifamily Optional Calculation

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Flicker50

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Washington
MIKE HOLT

In Unit 10 -Multifamily Dwelling Calculations Page 422 of your book titled: "Electrical NEC Exam Preparations" 4th edition (2005) In 10.5 Multifamily -Optional Method example you list a Waste Disposal with a 1.5 VA rating. My question is why is that not counted or included in the Appliance Calculated Load Example page 423. You have made it very clear that we don't count the washing machine multiple times threw out the book (See italic note washing machine as they are included in the Laundry Circuit). No mention is made of the disposal. Is the Waste Disposal unit included in the Kitchen Small Appliance Circuit or should have it been included in that portion of the calculation? Signed Confused.
 
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BAHTAH

Senior Member
Location
United States
Multi-Dwelling Load Calc

Multi-Dwelling Load Calc

220.84(B)(2) 2005 NEC This laundry circuit includes the load for the gas dryer and washing machine. 220.84(C)(4) covers the disposal motor load. The kitchen small appliance circuits (2) required, are not allowed to supply the disposal although the refrigerator is allowed. You must meet the requirement of 220.84, three or more units, electric cooking equipment, ect. Hope this helps sort things out. I do not have the book you are looking in but do have the 2005 NEC.
 
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gndrod

Senior Member
Location
Ca and Wa
Disposer in 220.84

Disposer in 220.84

Flicker50 said:
MIKE HOLT

In Unit 10 -Multifamily Dwelling Calculations Page 422 of your book titled: "Electrical NEC Exam Preparations" 4th edition (2005) In 10.5 Multifamily -Optional Method example you list a Waste Disposal with a 1.5 VA rating. My question is why is that not counted or included in the Appliance Calculated Load Example page 423. You have made it very clear that we don't count the washing machine multiple times threw out the book (See italic note washing machine as they are included in the Laundry Circuit). No mention is made of the disposal. Is the Waste Disposal unit included in the Kitchen Small Appliance Circuit or should have it been included in that portion of the calculation? Signed Confused.
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Flicker50,

I do not have the book you mentioned so the answer given is the load calculation parameters in the NEC Art.220 for Multi-family. (basically the same as Grant's comments)

First up, I am not sure where the 1.5kVa for a disposer comes into play from the Exam Prep book, but from the NEC [220.84(C)(3)] Appliances FIP and Specific Circuits, the Disposer NPR in [NEC220.84(C)(4)] (all Motors) is applied. The disposer sizes vary as you know anywhere from 920 va to over 1500 va, so realistically a project spec'd appliances is what I use for the service demand determination.
I might add to Grant's mention of the use of the 220.84(A) multi-family optional method that both an electric cooking appliance (range) and electric A/C-space heating (largest load used) is the Multi-family optional qualifier requirement.

The major Demand Factoring unit percentages is applied to the sum totals of:
a) sq.ft. va, b) kitchen 2 SA ckts, c) the Fastened-in-place specific and motor NPR's, d) the largest heating or A/C loads.

The laundry 210.11(C)(2) can be excluded from the above sum and applied to the house load subtotal (if a common laundry) that is additional to the Table 220.84 DF units percentage subtotal. I believe the common laundry use is the reason why the clothes washer is set aside from the total NPR as it is most likely not in each unit. Look for this piece of data in a question involving multi-family. rbj
 
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mcclary's electrical

mcclary's electrical

Senior Member
Location
VA
Flicker50 said:
MIKE HOLT

In Unit 10 -Multifamily Dwelling Calculations Page 422 of your book titled: "Electrical NEC Exam Preparations" 4th edition (2005) In 10.5 Multifamily -Optional Method example you list a Waste Disposal with a 1.5 VA rating. My question is why is that not counted or included in the Appliance Calculated Load Example page 423. You have made it very clear that we don't count the washing machine multiple times threw out the book (See italic note washing machine as they are included in the Laundry Circuit). No mention is made of the disposal. Is the Waste Disposal unit included in the Kitchen Small Appliance Circuit or should have it been included in that portion of the calculation? Signed Confused.
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It's "through" not "threw"
 
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gndrod

Senior Member
Location
Ca and Wa
jumper said:
The disposal was a typo. The errata for the exam prep can be found here:
http://www.mikeholt.com/documents/catalog/05_EP/05_EP_Correx_Directory.pdf
Look at the page in your book right before the table of contents, it tells you this. The web page is costantly updated.
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Hi Jumper,
I do not have the book so could you elaborate on the list the disposer is being removed from?

pg.422 Disposer to be removed from list.

I am not sure but the NPR is part of the 220.84(C)(4) all motors inclusive for part of the Demand Factoring. I believe the disposer is an FIP to be included. rbj
 
jumper

jumper

Senior Member
Location
3 Hr 2 Min from Winged Horses
The disposal was not supposed to be on the original list. There is no disposal. All the other calculations for the problem are correct. Your guys answers are correct, but there is no disposal. The errata corrections tell us to delete it when working the problem.
 
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gndrod

Senior Member
Location
Ca and Wa
jumper said:
The disposal was not supposed to be on the original list. There is no disposal. All the other calculations for the problem are correct. Your guys answers are correct, but there is no disposal. The errata corrections tell us to delete it when working the problem.
Click to expand...

Gotcha. This was a low bid job with garbage disposers left out of the test question. Tx, rbj
 
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