Residential Appliances

Status
Not open for further replies.
N

necnotevenclose

Senior Member
While working on a 14-story residential unit, I recieved from the architect a list of appliances for the residential units. The list included the basic kitchen needs a refrigerator, microwave, oven and a dishwasher all from one manufacture. After looking over the electrical connection requirements I found that the information provided by the manufacture is not so clear cut. For instance the refrigerator states it's running amps is only 1.1 amps, but then you also have sperate line items for the the condenser, heater, ice maker and some even have a TV connection that I think should all add up for a single total load. I encountered another manufacturer load problem with the microwave oven the watts read that it is 950W but the amps are rated at 14A if I do my math correctly 950W/120V=7.92 thats a difference of 6A. I called the manufacture to find out total loads and load discrepencies and they could not explain why there was conflicting information.

So my question has anyone encountered this problem and how was it solved?
 
necnotevenclose said:
I encountered another manufacturer load problem with the microwave oven the watts read that it is 950W but the amps are rated at 14A if I do my math correctly 950W/120V=7.92 thats a difference of 6A. I called the manufacture to find out total loads and load discrepencies and they could not explain why there was conflicting information.
Click to expand...

I'm surprised the manufacturer couldn't explain the difference. In the case of AC, Volts * AMPS is VA, not Watts, unless the load is a pure resistance load. For other loads Watts = V*A*Pf, where Pf is the power factor of the load, which varies significantly. (It's really always V*A*Pf, but a resistive load has a Pf of 1.) In this case the Pf for your 950W microwave would be 57% if the 14A is correct. In this case you need to ignore the watts and use the manufacturer's nameplate amps for calculating the load on the microwave circuit. If you are filling a 14 story building exclusively with their products, I would expect them to bend over backwards to provide the necessary data.

You need to follow-up with the manufacturer and get the nameplate loads for the other appliances as well
 
Typically microwaves have a rating in wattage, this is the output of the microwave, and a rating in amps this is the input or the load. The two numbers aren't the same.
 
A residential refrigerator may be powered either by a dedicated 15a circuit or share a 20a small-appliance circuit; your choice.

Microwaves are usually rated for cooking watts, not power consumption; use the ampere rating. Both are non-continuous loads.

(Okay, so I post slowly)
 
Status
Not open for further replies.
Top