and... electric clocks aside, for larger items, like your central air,
the circuit and the load are usually matched closely enough to keep the
load itself from burning up if there should be a problem.
Unfortunately, it's you with the reading comprehension problem. If you
didn't suffer this you would have noted my original point. I'm done with
this now - you're a waste of time and not at all entertaining.
I got a new shotgun. I'm only going to shoot at targets that are
close until it's broken in so I won't strain it.
"We should be careful to get out of an experience only the wisdom
that is in it - and stop there; lest we be like the cat that sits down
on a hot stove-lid. She will never sit down on a hot stove-lid
again---and that is well; but also she will never sit down on a cold
one anymore." - Mark Twain
Just got back from sears and HD. Sears had a 5hp which the motor was rated
at 22.5FLA. What does FLA mean. HD had a advertised 7hp rated at 17.3amps.
When I looked at the HD 2 weeks ago it was $100 less than tonight? So
Saturday I'm going to Lowes an see what they have, but online I'm leaning to
this one.#20849 for $637 in my area and if I open a new charge I think I can
get 10%. Will check the specs and get back to you all.
Looks like some _dreadful_ efficiency numbers, or a humongous phase-angle.
3hp == 2237 watts.
17A @ 230v is 3910 VA (or watts at 0 phase-angle.)
17A @ 240V is 4080 VA (or watts at 0 phase-angle.)
2237::3910 equates to a 57.212% efficiency
2237::4080 equates to a 54.828% efficiency.
Postulating 85% mechanical efficiency for the motor, that gets an
input power of 2632 watts.
Takes a _substantial_ phase-angle to make 2600 watts equivalent to 3900 VA.
You're missing a point. He said that that as "per 430.148 in the NEC".
That is an electrical code table used for sizing circuits, not the actual
rating or current draw of any particular installed motor.
Reply to jclarke at ae tee tee global dot net
Well, if you're going to be doing some shopping around then take the time to
go out to Campbell Hausfeld's site and look under Hot Buys. They have some
great deals on reconditioned compressors. Much less than retail and fully
warranted. I don't know who builds Sear's compressors for them, but both
Home Depot and Lowes use CH compressors. CH does not build a spec
compressor, so what you get from HD is the same compressor that you would
get from Lowes, or directly from CH with the possible exception that the
private label stuff might have some extras thrown in.
I got 10% off the same model from CH's hot buy($580) for opening up a new
account at lowes so the price was 570. It's rated at 4hp and 17.3 amps and
so far runs great on a 15amp breaker, but I will upgrade to a 20amp later
this weekend. See new post for air line setup.
Make sure the wiring is sized for the twenty amp breaker. It needs to be at
least 12 ga. or larger for a long run.
If it is on a 15 amp breaker now, I would suspect 14 ga. wire, much too
light for a twenty amp breaker.
FLA = Full Load Amps
LRA = Locked Rotor Amps
1 HP = 746 watts so FLA x running voltage / 746 gives a pretty good idea
of the real HP. Take advertised HP with a grain of salt. Especially
My 5HP motor is 21 amps at 240 volts. That said, the motor is a replacement
for a three phase unit and I didn't know about "compressor horsepower". My
motor is 5HP continuous duty, not intermittent. It's on a 30 amp breaker.
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