I think my compressor is screwed

[Toenges]

Working on a glasco gbv50.  Just recharged the compressor with r12.  I replaced the overload relay and starter relay with a supco ro41.  The supco ro41 gets really hot.  The compressor cools the machine down but then quits cooling.  Compressor keeps running and get hot.  I don't know if the compressor is bad or there is a leak of refrigerant.  I am thinking about getting a new compressor for the glasco.  I want to just replace the compressor and keep theoriginal fan and condensor radiator instead of buying a complete compressor package.  Can you suggest what I should do to check if the original compressor is still good or suggest a new compressor?

Thanks,
Buck

[johnieG]

Have you put a test gauge set on the system yet? what are your high &  low-side pressures?    It might be a restriction causing the compressor to load up & pull too much current, that would cause the Supco unit to Overload/get hot & trip open...

The Supco RO41 you're using is rated for a 1/4 to 1/3 HP compressor, so if it's overheating, then you've definitely have a loaded compressor probably from either a high-side restriction or the compressor's piston is physically getting tight in its bore as it gets under load. (

You said you recharged the system with R12, fine, HOW did you add the refrigerant? did you weigh it in.. or did you just add one or two cans? (not trying to dis -you, just trying to get to the root-cause of your troubles.. something to double check is to make sure you've returned the service valves fully back to the normal/operating position & didn't leave it in partially closed (causing a restriction) Also did you replace the filter/drier? new refrigerant can stir up sludge That choke off the flow of freon or it can plug the capillary tube
.
Remember, if you don't have gauges on it, you only have a guesses as to what's going on.  

[Toenges]

You said you recharged the system with R12, fine, HOW did you add the refrigerant? did you weigh it in.. or did you just add one or two cans? (not trying to dis -you, just trying to get to the root-cause of your troubles. I weighed 8 oz of r12 .

something to double check is to make sure you've returned the service valves fully back to the normal/operating position & didn't leave it in partially closed (causing a restriction) Also did you replace the filter/drier? new refrigerant can stir up sludge That choke off the flow of freon or it can plug the capillary tube   I did not replace the drier.  I don't know how to return the service valves to normal operating position.  
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Remember, if you don't have gauges on it, you only have a guesses as to what's going on I know how to check the low side with the gauges but I don't know how to gauge the high side  

[johnieG]

No Problem, here's a link to show you how to operate the valves, keep in mind that yours are mounted vertical (standing upright) while the ones in the video are horizontal (laying on their side) but they operate in the same way .... https://www.youtube.com/watch?v=NaFFdfTTEfQ        The low-side valve is connected to the larger size copper tubing & goes into the side of the compressor....the high-side valve is located on the smaller steel tube coming off of the bottom of the condensing coil (some people call it the radiator) both valves operate the same in regards to opening & closing them,  what you're looking for is first hook up your gauges to the service nipple on the valves, then make sure both of the service gauge knobs are closed (blue is low, red is high) "crack" open the valves about 1/2 to 1 turn, at this point they'll both should show pressure typically between 40-80 psi depending on the room temperature...now turn on the machine & watch the gauges, their needles will start to move...the  low/blue gauge should start to go down & the high/red gauge should start to rise, a typical pressure on the low/blue will be around 25 down to 10psi ( for R12) & the high/red should settle in around 120-135-ish ( depending on how warm the bottle compartment & the room is) now if your high/red starts to climb beyond say 145-200+ this means the high side is blocked, you would typically ALSO see at he same time the low/blue gauge start to fall below 10-psi & even go very low into the negative this will cause the compressor to draw too much current, and  the ro41 to overheat & probably "click" off.    this restriction could be from a few things such as a plugged filter/dryer, a partially plugged/restricted capillary tube.   the associated links shown with the "how service valves work" video are also usefull in understanding what the gauges are telling you, while A.C. / HVAC gauges show somewhat higher operating ranges in use, the trouble-shooting principles are  the same what you DONT want to do is runn the system with a restriction because A: it won't get cold" & B:it will overheat & damage the compressor to the point wher you'll have to replace it.  well I know this may seem a bit much to take in all at once, but it will get you started into finding what's going on with your machine.  remeber, it's a heat-pump, it can't get cold I fit can't move the heat out of the bottle compartment, that's the job of the Freon & the compressor is the heart of the machine...hope it helps.

[johnieG]

So, any progress?   

[johnieG]

Zzzzzzzz .......

[Toenges]

Thanks for the reply.  Been busy on other projects.  I will try and see what happens but I think the compressor is cooked.  I'll let you know.

Buck

[Toenges]

           " The low-side valve is connected to the larger size copper tubing & goes into the side of the compressor....the high-side valve is located on the smaller steel tube coming off of the bottom of the condensing coil (some people call it the radiator) both valves operate the same in regards to opening & closing them." 
               I don't think my glasco gbv50 has a high side service valve. so what do I do? 
        The low side is the same as the suction side correct?  This is the service valve that I added R12.

Thanks,
Buck

[johnieG]

If your machine only has a low side service valve, then that’s all you can check, if the compressor is actually running & it has a freon charge, you should see about 15psi on a  normally charged system but if it’s low o freon, it may be very low pressure showing ~5 to -10 psi, when you first turn it on it will start off at around 40-60 psi & then start dropping down towards 20-15 psi as the box gets colder (assuming that the compressor is actually working)

[Toenges]

Here is what I get.  The low side does start at 40psi when cooler is started.  It then drops down to 20 after 8 minutes, But the compressor gets really hot and the supco ro41 gets stinking hot.  The temp statrs to cool down and then stops.  I have to turn off the compressor.  No frosting occurs on the low side anymore.  It did at one time but it was frosting all the way to the compressor.  I'm pretty sure the tecumseh 1/4hp compressor is toast.  The machine itself is in really nice condition.  I would like to replace the compressor but don't know which compressor to use.  I'm going to start new thread on repairing the compressor deck.

Thanks,
Buck