Replacement Starter Relay for GE 3/4 H.P.

gunner66 · Post by **gunner66** » Thu Apr 28, 2011 6:49 pm

I am really going through my greenie 1957 SS and repairing/replacing as needed. The motor is the GE 3/4 h.p. with the capacitor and starting relay. The starter relay appears to be starting the motor fine, but has a slight vibration causing it to "buzz" at the metal pivot points when the motor is running. The contact pionts are clean and the coil seems fine, just some wear on the internal metal housing where it pivots. If I move the metal pivot over a 1/32", then the buzzing stops.

My question is this: Can a "universal" type relay be used if this one craps out (from Grainger or McMaster-Carr)- what would I be looking for specifications wise? One post shows a MARS 550 Potential Relay as a replacement, but is this the only one that will work? I am not picky about mounting the relay in the original location on the motor. Thanks for all the help thus far. Chris in GA.

justplaingoofy · Post by **justplaingoofy** » Thu Apr 28, 2011 7:02 pm

Can you post a good close up of that relay you are referring to please?

gunner66 · Post by **gunner66** » Thu Apr 28, 2011 8:40 pm

My digital camera is broken, but it looks exactly like this one (see link below):

https://forum.shopsmith.com/viewtopic.php?t=3227&highlight=3arr1

On the case the relay is marked: "3ARR1 AE73" and made in 1956.

JPG · Post by **JPG** » Thu Apr 28, 2011 9:23 pm

gunner66 wrote:I am really going through my greenie 1957 SS and repairing/replacing as needed. The motor is the GE 3/4 h.p. with the capacitor and starting relay. The starter relay appears to be starting the motor fine, but has a slight vibration causing it to "buzz" at the metal pivot points when the motor is running. The contact pionts are clean and the coil seems fine, just some wear on the internal metal housing where it pivots. If I move the metal pivot over a 1/32", then the buzzing stops.

My question is this: Can a "universal" type relay be used if this one craps out (from Grainger or McMaster-Carr)- what would I be looking for specifications wise? One post shows a MARS 550 Potential Relay as a replacement, but is this the only one that will work? I am not picky about mounting the relay in the original location on the motor. Thanks for all the help thus far. Chris in GA.

Start relays are voltage sensitive and calibrated to pick/drop at specific voltage ranges.

The ge relay is speced to pick at 111 to 134 v and is rated at 130v. It stays picked until the voltage drops below 40v.

A universal relay is not calibrated as such, but will probably work(sorta). You need to be sure it picks reliably at startup, stays picked under all load conditions(including temperature) and does not drop out too soon at power down.

The mars550 is yer best bet considering it is the same mount etc.

gunner66 · Post by **gunner66** » Thu Apr 28, 2011 10:55 pm

Thanks JPG,
I looked up the part and Motors & Armatures, Inc. (MARS) still/currently manufactures the MARS 550 GE Potential Relay (P/N: 19550). The specifications were exactly as you indicated. I filed this info away if I ever need to replace mine. Thanks again

for explaining and providing the relay's specs.

The company's website is: marsm-a.com

JPG · Post by **JPG** » Thu Apr 28, 2011 11:02 pm

gunner66 wrote:Thanks JPG,
I looked up the part and Motors & Armatures, Inc. (MARS) still/currently manufactures the MARS 550 GE Potential Relay (P/N: 19550). The specifications were exactly as you indicated. I filed this info away if I ever need to replace mine. Thanks again for explaining and providing the relay's specs.

The company's website is: marsm-a.com

They match the original GE spec for that 'model'.

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Replacement Starter Relay for GE 3/4 H.P.

Replacement Starter Relay for GE 3/4 H.P.

Additional relay info