Water heater

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rangerfan

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This may be elementary, but 422.13 states that a water heater is to be considered a continuous load. When sizing a feeder, the water heater should be considered as a fixed appliance. If there are 4 or more fixed appliances, then I can apply a 75% demand factor to the appliances (220.53). In all of the literature that I have explored on feeder sizing, I see the 125% factor missing from the water heater in computing the demand load on the feeder. For example, assume I have a 1200VA dishwasher, a 5000VA water heater, a 1000VA disposal, and 1000VA microwave for my fixed appliances. The demand is typically computed as:

(1200+5000+1000+1000)VA x 0.75 = 6150VA

But, what about the water heater being a continuous load???? Why not perform the following computation:

(1200+5000x1.25+1000+1000)VA x 0.75 = 7088VA

Does anyone have the correct answer? Need help.
 
422.13 deals with branch circuit sizing not feeder sizing.

Pete

p.s. Welcome to the Forum
 
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Bad test question!

Bad relationship maybe ?

If this is a hot water dispensor it could well be within the scope of 220.53, the appliance runs about 1500VA. And yes some have a two gallon storage capacity so your precentage is also still in. If this is a mini or even a standard size water heater then no! How could it be it's two pole application.

220.53 at the bottom states all for this four or more applicance circuit (praphrasing).

I've never heard of a two pole breaker used for a combined 2 phase and single phase application/load. I've seen 3 pole breakers using only 2 poles, not using the 208 leg.
 
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