One old electric motor runs on 110 or 220 Has 4 wires and mo capacitor Im told to run 2 phase 220 hook a hot to 1 and hot to the other. NO neutral needed. I can not get my head around how it will work with no neutral. Can it be explained where an old bonehead DIY can understand? Is it safe? Do I or can I run Neutral to chassis ground?
Electric motor From the OLD Dept
- Thread starter stsguy
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wyliesdiesels
Well-known member
There is no 2 phase 220v. Its single phase 240v
Pics are blurry but looks like 2HP
If you run it on 240v, you do not need a neutral.
If you run it on 120v, you WILL need a neutral.
notice the wiring diagram in pic 2?
high voltage diagram is for 240v.
Low voltage diagram is for 120v.
Pics are blurry but looks like 2HP
If you run it on 240v, you do not need a neutral.
If you run it on 120v, you WILL need a neutral.
notice the wiring diagram in pic 2?
high voltage diagram is for 240v.
Low voltage diagram is for 120v.
alfredeneuman
Well-known member
There is such a thing called 2 phase, but you don't have it. It's called single phase or split phase.
The windings represent the area on the diagram between the connection points.
The 4 windings can be series connected for 220, or parallel for 110.
You're looking at only the motor and not the supply
It needs a neutral for 110, and none for 220.
For 110 it just needs a 1 pole breaker, 220 a 2 pole.
(EDIT) The 110 supply's voltage will actually be 120, and 220 will be 240
Never run a neutral to the chassis (equipment) ground
Last edited:
MBfreak
MEMBER EMERITUS
This may be a repulsion motor?
Does it have carbon brushes under the louvred sheet metal cover?
Interesting design, has been extinct for several decades. Now brought back to life in cooperation with power electronics by ABB.
Ola
Does it have carbon brushes under the louvred sheet metal cover?
Interesting design, has been extinct for several decades. Now brought back to life in cooperation with power electronics by ABB.
Ola
Definitely a repulsion start motor. They are good motors, better starting torque than capacitor start motors. They are expensive to make with their wound rotor.
The motor needs 220-240 when wired for high voltage. All it needs is two wires with 240V between them, non of the other details matter.
The motor needs 220-240 when wired for high voltage. All it needs is two wires with 240V between them, non of the other details matter.
pistolpete1313
Well-known member
Everyone else is correct on the wiring portion but your question about why you don't need a neutral.
On 120, the neutral is the return path.
On 240 each leg is 120 but 180 degrees out of phase so the second leg is the return path
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alfredeneuman
Well-known member
I explained in post #3 "It needs a neutral for 110, and none for 220"
Thank all of you for the feedback Seeing the same answer puts my mind at ease. 
So I misspoke I guess (2phase.) I'm talking about the 2 hot leads that come in from the pole. Like my welder, I hooked up 110 from rt rail and 110 from the left as it will be problematic if hooked up on a single (Pole?)
But you guys know what I mean and I think I understand you, as well...
I can order a beer in many countries but only speak English lol I'm going to run a chassis ground
(NOT from the neutral rail just a ground.) even though it seems to work about the same It is starting to make enuff sense to confuse me even more...
more I'm intrigued enuff to look into beginners electronics and electrical classes... I've never been afraid to work on electronic boards, motors, etc. But there is so much to learn. It makes me respect the pioneers that did all this stuff the 1st time It's just an amazing subject ... 
Ill post a video of a running compressor
or a video on me running down the road doing my best Richard Pryor impersonation ...Thanks, again folks
Joe
GOTTA KNOW JOE HOBBIES
SPRING TX
