1954 Greenie Motor Just humms

[JPG]

In the case at hand(greenie motor) the start switch has only a normally closed set of contacts. When power is applied the run windings are always energized. The start coils and capacitor(switch closed) create a rotating field that the rotor will follow(start to rotate). Once the rotor is 'rotating' the normal run mode is established(currents induced in the rotor) and the start circuit is no longer necessary so the centrifuguly operated start switch opens. In this case the switch is internal.


However there are some GE motors that have an external start relay. That relay also has normally closed contacts. Once running, a small current(actually a voltage sensitive relay) is generated in the start winding that causes the start relay to 'pick' and thus open the contacts. That generated voltage is greater than the voltage across the relay coil when motor is starting.

All this is more than you need to know for the task at hand. Wherever the contacts are located,(internal centrifugal switch or external start relay) they need to be checked to make sure they are closed 'at rest'. That is step one.

All this extra info lets you understand how it works when 'normal'.

Humming/growling is not normal.

[ERLover]

Thanks JPG, enough knowledge for now, I will revisit here next week when I have that puppy here.

[billmayo]

I found that the current start relay (3ARR1) is the problem on almost all of the 3/4 HP non-operational (buzzing) motors. The Mark VII 1 1/8 HP motors used this same current start relay. The only way I found to test these relays is to have an operational motor and then swap the current relays onto the operating motor. Yes, I found more current start relays was bad than maybe one capacitor that was bad. I never found a good replacement for this relay. I had a few bad winding motors where I saved the relay as a replacement. I used a 3/4 HP motor where the current relay works and the motor operated but when the relay was switched to another motor, all I get is a buzzing. The windings ohm values looked good on these buzzing motors. Some day with help (backhertz maybe), I hope to check out few non-operating 3/4 HP motors (buzzing) that I still have.

[ERLover]

I found that the current start relay (3ARR1) is the problem on almost all of the 3/4 HP non-operational (buzzing) motors. The Mark VII 1 1/8 HP motors used this same current start relay. The only way I found to test these relays is to have an operational motor and then swap the current relays onto the operating motor. Yes, I found more current start relays was bad than maybe one capacitor that was bad. I never found a good replacement for this relay. I had a few bad winding motors where I saved the relay as a replacement. I used a 3/4 HP motor where the current relay works and the motor operated but when the relay was switched to another motor, all I get is a buzzing. The windings ohm values looked good on these buzzing motors. Some day with help (backhertz maybe), I hope to check out few non-operating 3/4 HP motors (buzzing) that I still have.

First, Bill, I am glad you are still with us!!! I hope you are doing well, or as my 96 mom sez, "Well as I can be"!!
2nd, thanks for the info, but to an ignorant like me, sorry to say I got nothing from your info, as accurate as I am sure it is. What I got you can only check that with an operating motor??
I am going to PM you, so look for it please.

[ERLover]

Skip at MKC Tools is back from vacation, as of today, I have him working on a few items, the 6" pulley for one. I will talk to him about dealing with it and cost. Shipping will suck, and checking here Monday at a authorized Ridgit/Delta/Bosh ect repair place, and they do others too.

[JPG]

The relays come apart easily. The contacts can be burnished. My sample of one had a sticking armature(the part that pushes the contact open) that was preventing the contact from closing. Judicial 'abrading' and it became a good servant again.

Be aware that internal spring tension and parts spacing is critical.

[ERLover]

I got this PM from Bill M last night, sez he still kicking but not enough for any shop time. This is FYI.
billmayo wrote:I found that the current start relay (3ARR1) is the problem on almost all of the 3/4 HP non-operational (buzzing) motors. The Mark VII 1 1/8 HP motors used this same current start relay. The only way I found to test these relays is to have an operational motor and then swap the current relays onto the operating motor. Yes, I found more current start relays was bad than maybe one capacitor that was bad. I never found a good replacement for this relay. I had a few bad winding motors where I saved the relay as a replacement. I used a 3/4 HP motor where the current relay works and the motor operated but when the relay was switched to another motor, all I get is a buzzing. The windings ohm values looked good on these buzzing motors. Some day with help (backhertz maybe), I hope to check out few non-operating 3/4 HP motors (buzzing) that I still have.

[reible]

I got this PM from Bill M last night, sez he still kicking but not enough for any shop time. This is FYI.
billmayo wrote:I found that the current start relay (3ARR1) is the problem on almost all of the 3/4 HP non-operational (buzzing) motors. The Mark VII 1 1/8 HP motors used this same current start relay. The only way I found to test these relays is to have an operational motor and then swap the current relays onto the operating motor. Yes, I found more current start relays was bad than maybe one capacitor that was bad. I never found a good replacement for this relay. I had a few bad winding motors where I saved the relay as a replacement. I used a 3/4 HP motor where the current relay works and the motor operated but when the relay was switched to another motor, all I get is a buzzing. The windings ohm values looked good on these buzzing motors. Some day with help (backhertz maybe), I hope to check out few non-operating 3/4 HP motors (buzzing) that I still have.

Boy that sure sounds like what he said in post 221159, are you trying to run your post count up or what?

Ed

[JPG]

You expecting him to remember what he said/did almost a day before?

[ERLover]

You expecting him to remember what he said/did almost a day before?

I did not know Bill had that posted here somewhere. As I said it was in a PM I got from him.
I do remember if you are referring to me, and not Bill.
No I am not looking for any post count contest/winnings. That is why I did not respond to it.