circuit breakers

[Maxim]

Can anyone direct me to a list of circuit breaker amp ratings for various typical home appliances? I'm ready to install a large water heater (80gal) and water softener (45,000grain) and want to know what size circuit breakers to use. I know the water heater should be on its own circuit, the pre-existing 50gal ran off of a 50amp breaker. Is this enough to sustain the larger unit?
The softeners installation manual only indicates that it needs to plug into a receptical with 120v - 60Hz, this is greek to me, and that is all the info it provides. I have no pre existing outlet to plug into. Can I tie into the overhead lights which currently run off a 20 amp breaker or do I need a seperate breaker for the softener as well. Any advice is appreciated

[kactuskid]

You have to look at the literature on the side of the new heater to see how many amps it draws or what the wattage is, it could very well be different than your existing heater and require a larger breaker and larger gauge wiring, can't say though until we know the above. Here's a link showing cable and breaker sizing.

http://www.electrical-online.com/howtoarticles/wireandcable.htm

As for the softner, same thing, how may amps does the nameplate say it draws (or watts). A 20 amp circuit can have a load not exceeding 2400 watts. What else is on the circuit you want to tap besides the overhead light?

[volts]

Maxim: The softener certainly should have a nameplate with its specs. But if all avenues for the softener requirement are dead ends, you can measure its current draw with an Amprobe. But you have to rig a simple "test jig" to do so. As a general rule, I avoid mixing lighting feeds with appliance feeds; the reason should be obvious.