Electric Motor's Wiring & Information

[crash325]

First off is a 2 HP, 1725 RPM, 220V motor on a 2 cylinder compressor. Picture 1 is what I think powers up the capacitor's for starting, then cuts out. ?? The wiring it has been messed with. All the other wiring looks like it has been left alone. #1 Just want to see if the motor will start & run. It and the compressor turn easy by hand.

Now on motors themselves. Does a 1725 RPM motor make more torque than a 3450? The big 220 V is about 3 times as large a 110V 3350 motor on a table saw. Why so big for 2 HP? Is a 110V, 2 HP, 1725 RPM just a strong torque wise?:confused2:

Thanks Guys

 

[Gordon Gould]

For a rotating power source:
Torque = ( 5252 X HP ) / Speed in RPM

Voltage doesn't matter. If you know the HP and speed you can calculate
the torque.

For an AC electric motor starting torque is a totally different thing from
running torque and generally depends on the winding configuration and
starting method.
A compressor usually needs a motor with high starting torque,

 

[Ken]

Looks like from picture #1 this box is the contactor for remote starting.
From the breaker box you would have a 220 line L1 attached to a terminal on contactor.
L2 would be attached to other terminal use a Ohm meter to make sure .
There also is a control voltage usually 110 volts to coil of the contactor which when applied will close contactor and give voltage to L1 and L2 to 3rd. picture. This motor looks like is wired for CCW runing and so would run at 11.3 amps.
The starting caps are used to start rotation then a clutch will switch to running windings when speed of rotation is 1730 RPM . There would be no extra wiring to start then run type operation.
Looks like also it has been sitting for some time exposed to the weather may be full of sand and would need to be cleaned up before used.
The large size is for air cooling when running.
Hope this helps.
ken

 

[crash325]

Looks like from picture #1 this box is the contactor for remote starting.
From the breaker box you would have a 220 line L1 attached to a terminal on contactor.
L2 would be attached to other terminal use a Ohm meter to make sure .
There also is a control voltage usually 110 volts to coil of the contactor which when applied will close contactor and give voltage to L1 and L2 to 3rd. picture. This motor looks like is wired for CCW runing and so would run at 11.3 amps.
The starting caps are used to start rotation then a clutch will switch to running windings when speed of rotation is 1730 RPM . There would be no extra wiring to start then run type operation.
Looks like also it has been sitting for some time exposed to the weather may be full of sand and would need to be cleaned up before used.
The large size is for air cooling when running.
Hope this helps.
ken

Thanks Ken,
Took a good look this AM. More questions. The 3rd leg for the 230V is a ground to the machine metal. Is that normal or common? What I have wired up in the past, (if memory is correct) center and 2 legs, ground optional? Wiring there looks original, but under size.

The motor is sealed, no air flow through it, so dust or dirt should not be a problem.

The reset switch only has one wire going to it. Doubt that it works. Pressure cutoff is 110v or 1 leg of the 230V

Does a 1730 RPM motor produce more torque than a 3350? Is like running a lower gear? Have another compressor that needs a motor, just as a test stuck a 3350 on it. Soon as pressure came up the motor bogged down.

 

[EE_Bota]

Thanks Ken,
Took a good look this AM. More questions. The 3rd leg for the 230V is a ground to the machine metal. Is that normal or common? What I have wired up in the past, (if memory is correct) center and 2 legs, ground optional? Wiring there looks original, but under size.

The motor is sealed, no air flow through it, so dust or dirt should not be a problem.

The reset switch only has one wire going to it. Doubt that it works. Pressure cutoff is 110v or 1 leg of the 230V

Does a 1730 RPM motor produce more torque than a 3350? Is like running a lower gear? Have another compressor that needs a motor, just as a test stuck a 3350 on it. Soon as pressure came up the motor bogged down.

At the same horsepower rating, say 2 HP, a motor at 1750 would have twice the torque as a motor at 3500.

For that Westinghouse nameplate, the rpm is stated, and your only choices is wheter to run it at 110, or 220. Also, you get to decide whether to run it clockwise, or counterclockwise.

 

[crash325]

At the same horsepower rating, say 2 HP, a motor at 1750 would have twice the torque as a motor at 3500.

For that Westinghouse nameplate, the rpm is stated, and your only choices is wheter to run it at 110, or 220. Also, you get to decide whether to run it clockwise, or counterclockwise.

Thank you EE. That is what I thought but wanted to be sure.

 

[Ken]

Thanks Ken,
Took a good look this AM. More questions. The 3rd leg for the 230V is a ground to the machine metal. Is that normal or common? What I have wired up in the past, (if memory is correct) center and 2 legs, ground optional? Wiring there looks original, but under size.

The motor is sealed, no air flow through it, so dust or dirt should not be a problem.

The reset switch only has one wire going to it. Doubt that it works. Pressure cutoff is 110v or 1 leg of the 230V

Does a 1730 RPM motor produce more torque than a 3350? Is like running a lower gear? Have another compressor that needs a motor, just as a test stuck a 3350 on it. Soon as pressure came up the motor bogged down.

The ground to frame of motor is a safety to keep from getting shocked. A motor wired for 1730 cannot be rewired for faster rpm use pully sizing to get faster speed .
Depending how long it has been sitting the starting cap may be bad. get # off cap for future referance . some have running cap also. Reasons for starting and running caps is simular to flywheel give additional kick as freq. pulses 60 cyc. Wiring size allows the amount of current to flow with out heating of wiring. ken

 

[Transit]

Why not take the motor to a shop and have it checked out by a pro?

 

[crash325]

The ground to frame of motor is a safety to keep from getting shocked. A motor wired for 1730 cannot be rewired for faster rpm use pully sizing to get faster speed .
Depending how long it has been sitting the starting cap may be bad. get # off cap for future referance . some have running cap also. Reasons for starting and running caps is simular to flywheel give additional kick as freq. pulses 60 cyc. Wiring size allows the amount of current to flow with out heating of wiring. ken

Hi,
I'm not doing to well with my questions.
Don't want it to run any higher RPM.
Right now just want to see if it runs at all and if compressor makes air.
I though that it should use 4 wires. 2 live - 1 common & 1 ground.
Guess it only needs 3??
Plan #1 Take wires off reset switch. Turn off power, wire motor direct and plug in. Turn power on. Worst that can happen is blow 2 45 amp fuses.

If that works, run larger wire to reset and wire through it. Replace it if it is dead.

Once all is working, run a power line just for the compressor with a cut off switch.

Good or Bad Plan??:confused2:

Taking to an electric shop not practicle. 40 Miles 1 way, 2 trips 160 miles, about $50 just for gas. Plus what ever they charge. The motor weighs over 75 pounds, hard to remove and carry.

 

[Ken]

Picture 3 shows L1 and L2 one wire of 220 from breaker. To L1 #10 wire The other side of breaker to L2.
Name plate states running load to be 11.3 amps. so 30 amp breaker would hold for the starting current. if trips breaker check the starting cap. if not running shut off the power and look at the starting winding if chared past owner had problems.
Hope for the best.
ken

 

[Ken]

Picture 3 shows L1 and L2 one wire of 220 from breaker. To L1 #10 wire The other side of breaker to L2.
Name plate states running load to be 11.3 amps. so 30 amp breaker would hold for the starting current. if trips breaker check the starting cap. if not running shut off the power and look at the starting winding if chared past owner had problems.
Hope for the best.
ken

Any new updates on motor . Did it spin or just grunt. or nothing at all.
Usually a reason to remove from service.
ken

 

[crash325]

Any new updates on motor . Did it spin or just grunt. or nothing at all.
Usually a reason to remove from service.
ken

Hi Ken,
Thanks for asking. Lots of other things going on, so letting that project rest for a while. Even if it runs and makes air, it will need a lot more work and parts. Maybe after the middle of the month.
Jim