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RE: computing electrical loads

To: <shop-talk@Autox.Team.Net>
Subject: RE: computing electrical loads
From: "Randall" <tr3driver@comcast.net>
Date: Mon, 15 Nov 2004 14:31:17 -0800
> Anyone know of a chart or whatnot that lists common amperage loads for
> things like:

I don't know of a chart anywhere, but these are easy.

> 100W lightbulb

Allow an amp.

> 3/4 hp garage door opener

7-8 amps if it's really putting out 3/4 hp.  Electric motors draw a big
start-up surge though, so I'd allow more like 10 amps to be safe, even
assuming you're using thermal breakers or slo-blo fuses.

> small 110V hot tub heater/pump

15 amps.

> Etc. etc. etc.?

As a (rough) rule of thumb (at 110v), it takes 10 amps  to make one
horsepower and 1 amp to make 100 watts.  That should get you pretty close.

The other rule is that a device is not allowed to draw more than 15 amps
continuous from an ordinary 110v outlet.  That's not much heat, so almost
anything that involves a heater will draw 15 amps (or close to it).  That
includes a lot of small appliances, like toasters, coffee pots, hair dryers,
etc.

Randall






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