Early 1950's GE LH-121 Combination Refrigerator Wiring Diagram

scottcl55

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Hi, I'm new to the forum and am in the process of restoring an early 50's GE LH-121 Combination refrigerator. I already restored one, and it it very nice, its like brand new and works great. So picked up another one at an estate sale and it needs some electrical work. I'm looking for the wiring diagram or schematic.
I know these were attached to the rear of the unit but they basically crumble and fall off after several years. Any help would be appreciated!
 

rickgburton

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Most of the older machines were wired the same way depending on what exactly does it have in the way of electrical components. Inside the box there's a cold control, light bulb receptacle, door switch. Anything else? By the compressor, is there a fan? What does the power cord connect to?
 

scottcl55

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Thank you for the response!
The compressor is an enclosed unit, no external fan. The compressor is not starting, it basically just keeps resetting the relay.
The power wire splits, one wire goes to the thermostat/control and the other wire goes down to the starter relay. Of course other spliced in wires go to lights etc. I have two of these refrigerators, The other one works perfectly On the unit that works I’m getting 160V at the relay, the other one I’m only getting 120V at the relay.
I’ve swapped the relays but it doesn’t make a difference. I’m wondering if there’s some kind of transformer, or step up voltage module of some type that steps up to 160V somewhere else on the unit.
I do need to mention that I never checked the voltage when I put the relay from the good fridge into the broken one. I’ll try that next just to verify since maybe this relay might be some type of a step up transformer and one relay is bad but the compressor is just frozen up.
 

rickgburton

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OK, what you're calling a relay is most likely something else. There is no transformer. I don't know where you're talking the voltage measurements. It's kinda hard to get 160 VAC out of a 120 VAC outlet. Is there a capacitor in the wiring? Maybe take a few pictures and post them here .
 

scottcl55

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There's a relay mounted to the back of the unit, see picture 1. The plug is supplying 120V and it appears that when the compressor starts up (on the refrigerator that works) the voltage goes up to 159V at that relay. There would have to be some type of voltage transformer somewhere in the system. This is why I'm looking for the wiring diagram, the whole 159V thing is throwing me, does it use 159V to start the compressor or does the compressor have the transformer embedded?
Ultimately though, it appears that the compressor is locked up. I wonder if there's a way to jump start the compressor, much like a home AC compressor where AC techs can use a capacitor to start a hard to startn AC compressor.
IMG_1128.jpgIMG_1127.jpgIMG_1125.jpgIMG_1126.jpg
 

rickgburton

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when the compressor starts up (on the refrigerator that works) the voltage goes up to 159V at that relay.
Because you're reading off the start capacitor when it starts. Here's how you wire in a 3-IN-1 hard start. Take note I don't show the wires connect to the compressor because the compressor terminal location varies across makes. There are three pins or terminals on the compressor, Common, Start, and Run. To determine which is which, use your meter to measure the resistance between the three pins. Measure between A-B, A-C, and B-C. The two pins with the highest resistance is the combination of the run and start windings so the pin without a meter lead on it is the common pin. Connect the black wire from the hard start to this pin. Now measure the resistance between the Common pin and the other two pins. The one with the lowest resistance measurement is the run windings. Connect the red wire from the hard start to this pin. Connect the white wire to the other pin or start windings.
Hotwire to Solid State no fan-5.jpg
 

scottcl55

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Thank you very much, I've ordered the 3-in-1 and will let you know later this week.
 

rickgburton

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OK sounds good. Keep us posted. Just to clarify, the Start windings should be between 3Ω-11Ω. The Run windings between 1Ω-5Ω. Any higher resistance measurements,the windings are bad.
 

scottcl55

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I'm getting 2.1ohms between the run and common leads which seems in tolerance and open between the start and common leads and run and start leads. Sounds like the windings in the compressor are bad. If that's the case, any recommendations?
 

rickgburton

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You're correct, bad compressor. Recommendations for a 50's era fridge with a bad compressor? Scrap metal.
 
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