electric motor

RH913RH

Hi all
just bought new 3hp 230v.single phase electric compressor duty motor.
connected it as per wiring diagram to get cw rotation.
motor tries to start but won't.
reversed the wiring to get it to run ccw, same problem.
checked voltage at receptical, 120 both legs
checked voltage at wire ends at motor, 120 both legs.
this is the second motor same problem. HELP?????

the circuit is controlled by a 20 amp breaker, the wire is 12 gauge to the outlet.

k_buz

What voltage do you get between the two legs?

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RH913RH

didn't check that will do that right now
250 volts across the legs

joed

I would have to guess that you did not wire it according to the wiring diagram or one of your connections is loose.

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RH913RH

Hi Joed
I checked and double checked the connections
also this is the second motor, same exact problem.
It's a dual capacitor motor. The first time I figured "bad capacitor"
But the same issue with the second, now I'm scratching my head???

It's on a compressor, so I thought it might be the pressure switch so I bypassed the switch and wired directly to the plug, no go.

RH913RH

wiring diagram is very clear.
THERE ARE 5 WIRES CLEARLY MARKED P1,T1,T4,T5,T8

CCW---------------------CW

P1----------LINE1--------P1

T1+T5...........................TI+T8

T4+T8----- LINE2--------T4+T5

micromind

This is not a standard connection, but here's how I believe it should be connected.

One of the incoming lines goes to P1.

T4 and T8 are connected together.

The other incoming line goes to both T1 and T5.

If the motor is wound standard, this will give CW rotation when looking at the back of the motor; normal for an air compressor.

Rob

P.S. If it turns the wrong way, swap T5 and T8.

RH913RH

Thanks for the help

It's a harbor freight motor
It's a dual capacitor 3450 rpm
I haven't looked at the capacitor connections
T1 AND P1 the circuit breaker

I did get it to start a couple of times by bumping the circuit breaker quickly on and off

JACK HOTTEL

Is it still 250 volts while the motor is trying to start?
Jack Hottel

k_buz

This is where you are going wrong.

Line 1 goes to P1....that is true.

But Line 2 goes to T4 and either T8 or T5 depending on rotation.

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RH913RH

k-buz
that's how I have it wired.

RH913RH

JACK HOTTEL
I didn't check it running

RH913RH

micromind
That creates a dead short since P1 and T1 are opposite ends of the overload breaker

RH913RH

The motors were gotten from 2 different stores miles apart, I doubt if they were made on the same line at the same time.

Defective capacitor twice????

k_buz

This is the part that is confusing me about your wiring.

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