A single dwelling unit feeder supplies five fastened-in-place appliances: a 1,200 volt-ampere dishwasher, a 900 volt-ampere disposal, a 4,500 volt-ampere water heater, a 1,000 volt-ampere trash compactor, and an 800 volt-ampere attic fan. No range, dryer, space heating, or air conditioning is included in this group. Applying the demand factor permitted when four or more such appliances are on the same feeder, what is the demand load?
- A8,400 VA
This is the connected nameplate total with no demand factor. Once four or more fastened-in-place appliances share a feeder, the code permits the group to be reduced.
- B3,360 VA
This applies 40 percent, the factor used for the remainder of the general load in the optional dwelling method. That percentage belongs to a different calculation method entirely.
- C2,940 VA
This applies 35 percent, the demand factor for the portion of the dwelling general lighting load above the first block. Lighting demand factors do not apply to fastened-in-place appliances.
- 6,300 VA
Why D is correct
Five qualifying appliances totaling 8,400 VA meet the four-or-more threshold, so the 75 percent factor applies to the whole group: 8,400 x 0.75 = 6,300 VA. The reduction recognizes that a dishwasher, disposal, water heater, compactor, and attic fan are very unlikely to be drawing full nameplate current at the same instant.
What this question is testing
Tests whether you can identify which appliances belong to the fastened-in-place group, whether you recognize the four-appliance threshold that unlocks the reduction, and whether you apply the correct percentage rather than borrowing a factor from the lighting table or the optional method.
On the job
Counting appliances correctly is worth real money on a service upgrade. Water heaters dominate this group, and adding a fourth qualifying appliance can actually lower the calculated load because the 75 percent factor suddenly applies to everything in the group. The exclusions matter just as much: put the range or dryer in this bucket and you have understated the service, because those have their own demand rules.
Memory technique
Four appliances buy you a quarter off.
Exam tip
Count the qualifying appliances first; at four or more, multiply the nameplate total by 0.75, and leave ranges, dryers, heat, and air conditioning out of the count.
Where to look it up
Article 220, Part III, appliance load for dwelling units. Read the list of excluded equipment in that section before you decide how many appliances you actually have.