Broken historic fridge

Dsisson

Hi folks, 
I have an antique icebox, converted into a fridge. 

It stopped cooling yesterday. I’m hoping to get it working … if I can’t I’ll call the pros on Monday.

it has a remote condenser in the basement, cooling coil and fan inside the icebox. 

It has power and the fans run, but the pump isn’t starting. 

Last time it did this, only a few months ago, the tech put a “3 in 1 kit” on it. 

Help? 

Jamie Hall

We had one of those... getting on for 80 years ago now. @ChrisJ is our local expert on ancient refrigerators -- give him a shout.

EBEBRATT-Ed

If he replaced the start capacitor/run cap and relay with a 3 in one and the compressor is not starting you either most likely have a bad compressor or the 3 in 1 is bad. Manufacturers parts are better than the generic 3 in 1. May be time for a new condensing unit and an r-12 replacement.

Dsisson

Is there any way to get the compressor to kick on, so I can see if it’s the compressor or the capacitor? It’s using R-409a by the way 

Dsisson

Ok, newsflash. 

I bumped the black 3-1 kit and the compressor kicked on. I assume that means one of the condensers is bad. 

Pic 1-this condenser is sorta built into the compressor? How do you replace it and what’s the part number?

Pic 2-the 3-1 kit itself-same question, what a factory part number? 

Mad Dog_2

Ammonia? Mad Dog 🐕 be careful 

pecmsg

That means the overload was open. As said those generic start kits are temporary. Get the factory start parts.

Start Relay K71-36

Start Cap K146-55

Overload K90-56

Dsisson

OK thank you. I'm sorry - this is probably a dumb question, but when I look at those parts, they look nothing like what's installed on the unit. I know the 3-1 kit is new, so the correct part will look different but it looks like there's a round capacitor stuck inside the compressor (my pic 1 above). It has 3 wires on it. I can buy the start relay, start cap, overload, but I don't know where to put them or how to wire them...maybe I need a professional...

Dsisson

Are the 3 wires I was pointing to the same as in this diagram? What does C, S, R mean?

Ironman

The 3 wires that you point to are the compressor terminals.

The condenser is the tubing coil with fins that cools the hot refrigerant gasses.

I think you really should call a pro on this.

Dsisson

Thank you, I probably will.

pecmsg

Call a commercial refrigeration contractor. Typical A/C contractor won’t have a clue. 

mattmia2

That is just a modern packaged commercial condenser. If the overload in that capacitor start kit wasn't sized right it will keep nuisance tripping and eventually burn out. I don't think you need a capacitor there, just get the appropriately sized start relay and overload or "solid state" start relay and overload.

It would happen if the cold control is short cycling the compressor too(that might be using a pressure control instead of a cold control in the cabinet).

It looks like that combo start control is good to 13 rla so my bet is on the controls are causing it to short cycle or possibly it has a leak somewhere in the field tubing so that pressure control is short cycling it.

csr=common, start, run

mattmia2

That improper service port o-ring cap is going to leak over time.

pecmsg

mattmia2 said:

That is just a modern packaged commercial condenser. If the overload in that capacitor start kit wasn't sized right it will keep nuisance tripping and eventually burn out. I don't think you need a capacitor there, just get the appropriately sized start relay and overload or "solid state" start relay and overload. It would happen if the cold control is short cycling the compressor too(that might be using a pressure control instead of a cold control in the cabinet). It looks like that combo start control is good to 13 rla so my bet is on the controls are causing it to short cycle or possibly it has a leak somewhere in the field tubing so that pressure control is short cycling it. csr=common, start, run

That compressor needs a start cap. 

pecmsg

mattmia2 said:

That improper service port o-ring cap is going to leak over time.

What service port. 

mattmia2

pecmsg said:

mattmia2 said:

That improper service port o-ring cap is going to leak over time.

What service port. 

ChrisJ

@Jamie Hall. Way too modern for me.

@Mad Dog_2 no residential refrigerator has ever used ammonia aside from the natural gas / lpg powered absorption ones.

Ironman

mattmia2 said:

 It would happen if the cold control is short cycling the compressor too(that might be using a pressure control instead of a cold control in the cabinet). 

This is a definite possibility. If the evaporator coil is fed by a cap tube, instead of a TXV, then a thermostat must be used to control the compressor, not a low pressure control.

pecmsg

mattmia2 said:

mattmia2 said:

That improper service port o-ring cap is going to leak over time.

What service port. 

That’s an access T. Perfectly acceptable

pecmsg

Ironman said:

mattmia2 said:

 It would happen if the cold control is short cycling the compressor too(that might be using a pressure control instead of a cold control in the cabinet). 

This is a definite possibility. If the evaporator coil is fed by a cap tube, instead of a TXV, then a thermostat must be used to control the compressor, not a low pressure control.

I see a receiver, so that better be an expansion valve system

Dsisson

The temp is controlled by the pressure controller. No thermostat 

Dsisson

OK, trying to think ahead. I'm assuming I'll need to replace the entire condensing unit soon.

It's a Tecumseh AE4440AB

It originally used Freon R12, but at some point they put R-409a in it.

What condensing unit should I be looking for? Another Tecumseh? Another brand?

I see the following models available:

AEA4440AXA (r12 model)
AEA4440YXA (r134A model)

AEA4440EXA (r22 model)
AEA4440BXA (R410A MODEL)
AEA4440ZXA (R404A / R507 MODEL)

Dsisson

Small update. I ordered a new 3 in 1 kit, to get me moving forward while I figure out what to do with this thing. Amazon brought it in 24 hours. The fridge is now cooling again. I tore apart the old 3-1 kit, and I can tell something burned, it smells like burned electrical inside of it. I assume the new 3-1 kit will do the same thing soon enough. I've been reading entirely too much internet discussions about 3-1 kits vs doing the right thing and replacing w/the factory components. On the one hand I hear "factory components work when the compressor is good, but they might burn out if the compressor is on it's last legs". On the other hand I hear "3-1 kit burns out the compressor"...

Obviously the 3-1 kit is poor quality. that's clear from opening up the old one. Sure was easy to install another one though, and cheap to buy it. Begs the question: cheaper and easier to just have a stock of 3-1 kits on hand than to buy the factory components?

And, my question above - should I just plan on replacing the entire condensing unit? If yes, then I want to plan ahead. If getting the correct capacitors and relays would solve the problem long term, then I should do that instead.

pecmsg

Order the factory parts. It was designed for those. 

Get the super Heat at the compress in to the 20 - 40* range. That is what cools the electrical windings. 

When it comes time to replace it install a suction filter to catch all the crap that the POE oil will try and bring back. 

Dsisson

OK, thank you @pecmsg

I'll order the factory parts. Maybe get a pro to put them on if the wiring isn't obvious to me. (the only reason I'm hesitant is that the folks that have helped me thus far are the same people that put the 3-1 kit on it in the first place and now I'm a bit suspicious of them)

Then, wait till it dies. Then, I'll decide what to do. Honestly I appreciate everyones time and advice. I do have a modern basement fridge too, so I'll survive even if antique beautiful fridge is on the fritz.

pecmsg

To adjust the SH at the compressor they’ll have to open that evaporator and adjust the x-valve. Could get a little labor intensive. 

Again look for a commercial refrigeration contractor, they SHOULD know better. 

As far a replacement refrigerants wait and see. 134a, 404a and most others are on the chopping block. R-290 is most common but Liquid Propane I’m still un sure of for obvious reasons. 

mattmia2

there is no reason you should need to replace that condenser in your lifetime if it was properly installed and is properly maintained.

mattmia2

both components likely burned out for reasons that have nothing to do with the start components or the compressor. is it short cycling?

Dsisson

OK, The fridge cooled off to 37 deg F, the condenser shut off. A few minutes later it turned on but the compressor failed to start. I could hear the 3-1 kit clicking as it tried to start the compressor. I let it do this for about 10 min while the fridge warmed up. I turned off the whole thing for about a half hour, and then turned it on, and the compressor restarted, but same result, once it hit the temp, the compressor wouldn't restart. HELP. New compressor??

pecmsg

No
not enough off time for the pressures to equalize as well as wrong start parts. 

Again Compressor superheat can cause it as well. 

mattmia2

mattmia2 said:

both components likely burned out for reasons that have nothing to do with the start components or the compressor. is it short cycling?

mattmia2

the short cycling is what burned out your first and second set of start components. if it is constantly tripping the overload it will burn out the overload. I don't know enough about how that pressure control works but i suspect an incorrect charge will cause it to drop too quickly on the suction side and turn off the compressor then the pressure rises quickly when the compressor is off because the evaporator isn't actually as cold as the pressure would indicate and restarts the compressor but it hasn't equalized yet so it can't start and trips out the overload. I suppose it could be the txv adjustment too, but i'll defer to others on how exactly the pressure control works.

Dsisson

How would I know if it was short cycling?

mattmia2

Dsisson said:

A few minutes later it turned on but the compressor failed to start. I could hear the 3-1 kit clicking as it tried to start the compressor. I let it do this for about 10 min while the fridge warmed up. I turned off the whole thing for about a half hour, and then turned it on, and the compressor restarted, but same result, once it hit the temp, the compressor wouldn't restart. HELP. New compressor??

that is short cycling. normally equalizing takes around a minute or less but the controls on that could take longer. if it is several minutes before it tries to restart just increasing the differential on the pressure control could do it but if you can find someone that knows commercial refrigeration well they would be a better one to figure it out.

pecmsg

Normally you look for 5 minuets off time.

Ironman

If the evaporator has a TXV, then the pressures won’t equalize. The TXV closes when the compressor stops and the compressor discharge valves are closed as well. This prevents the pressures from equalizing. In this scenario, the compressor requires a properly sized hard start kit to give it enough starting torque to overcome the unequal pressures.

If the evaporator is fed by a cap tube, the pressure will equalize in less than three minutes, but the temperature must be controlled by a thermostat, not a low pressure control since that will short cycle the compressor.

You need to remove the cover from the evaporator to see which type of metering device it has - cap tube or TXV.

EBEBRATT-Ed

With the correct starting components it will start if the pressure is equalized or not.

If you keep fooling with this and don't install the correct original starting components it may be that the compressor is already damaged, I would get the starting components start relay, run capacitor and start capacitor installed and see what happens. If that doesn't fix it you in for a new condensing unit

ChrisJ

Float valves also don't equalize.

Does that 3-1 use a solid state start relay that needs to cool before it'll work again?

mattmia2

ChrisJ said:

solid state start relay that needs to cool before it'll work again?

I'm not a fan of the PTC thermistor as a "relay".

Jamie Hall

To sort of muse, in a general sort of way, on all this. Single phase AC motors rarely get seriously damaged -- although it is possible -- if they have the correct overcurrent protection (the wrong overcurrent protection can result in fried coils). However, they do require the correct start and usually run capacitors to run well, if at all, and the correct mechanism to switch out the start capacitor at some point. On some older motors, that can be a centrifugal switch on the motor, and that can fail (if it leaves the start cap. in the circuit, you will see excessive running current which may trip your overload device -- if it doesn't engage the start cap., the motor either won't start at all or will not start under load)(the wrong running capacitor, if used, can also result in excessive running currents -- and a source of mysterious failure is just that, in combination with a resetting thermal overload device on the motor windings or in the field circuit -- the motor will run for a short time and quit, and won't restart until it cools).

The point of this ramble. There is no such thing as a universal combination of start capacitor, running capacitor, and start relay or switch. You can come "close enough" with the components off value much of the time -- but not always, particularly if the start condition is under load.

In the particular instance of this thread -- are the original components still available, or did they get junked? I hope they are still available, as if they are you can usually find enough information on their values to get a real replacement. That might help...