Today's Visitors - With a CA and a FEA......
Oct 20, 2019 3:00:33 GMT
ChrisJ, cablehack, and 2 more like this
Post by turbokinetic on Oct 20, 2019 3:00:33 GMT
So, yesterday and today I had some visitors! They drove down about 8 hours and brought two old Monitor Top cooling units. We were enjoying talking about and working on the units and I didn't, therefore, take a lot of pictures until the repairs were complete.
This FEA had a bad start-relay and a bad control. It also had super-rotten wiring. Its compressor is mounted differently from Paul's FEA, blocking access to the fan motor. We had to carefully bend the condenser out of the way to remove the fan motor out the front. After that, replacing the deteriorated wiring was possible. This motor is the original GE two-phase motor with an oil fill tube. Very nice design! I expected it to work and cool, which it did very nicely! It has the blue porcelain evaporator, as well.
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Notice the original mount locking tag is still in place.
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Nice full frost!
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Then there was the very, very sick CA-2-B16. I wasn't sure it was going to make it; and it's not fully "out of the woods" yet. It was seized when it arrived. We hit it with a capacitor and no action. Then hit it with 240V and it started, but ran very clattery and with over 400 watts power demand. Then it seized again. We put the heater on it and let it percolate with the heater getting 240V and warning the oil at 80 watts. Once the oil was nice and hot, another 240V start was made. After switching to 120V it continued to run, loudly and painfully, for about 5 minutes. Then it seized again - hard.
Having seen this issue before, I laid out all the tools to drill a hole in the dome and add 2 cups of (hopefully) life-saving oil into the compressor sump. First, I broke the vacuum in the system with nitrogen. Once that was done, a neodymium magnet was placed beside the point to be drilled. A greased drill bit was used to drill the hole. This captures chips and keeps them out of the housing. The hole was then tapped to 1/8" NPT pipe thread. We looked in the housing with a borescope and the winding and all paper components were clean and not burned.
Two cups of 150 viscosity AB oil was put in the compressor via the hole. Then a brass plug was installed with Loctite. You can see the plug to the left of the line on top of the dome.
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The compressor was then re-started with 240V again, and ran with rattling and high power demand. Rapid gas percolation was heard in the evaporator due to the float seat being eroded. After about 5 minutes, the oil had apparently not circulated, and the compressor started to slow down as if it was trying to seize again. It was powered off at that time.
The float seat area was then cut from the bottom of the chamber. The seat was re-cut to a round taper with a tapered grinding point, before the seat tube was re-soldered to the bottom of the float chamber.
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It took another 240V boost to start up, and the horrible rattle was still present. After the unit ran for about 10 minutes, the sound began to change. The rattle went away and the unit got quiet! After running for about an hour, and lots of NCG bleeding (due to the nitrogen put in the system) we had reasonable frost on the evaporator!
Sadly, after stopping the compressor, it would not re-start unless 240V was once again applied. To attempt to remedy this, a start-capacitor was added to the circuit, and tucked in between the fins a shown below. This provided for starting normally with 120V.
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The owner of these two fridges were out of time, as I would have preferred to let it run longer and continue purging. But the whole condenser was warm (but not the float chamber) and there was a good frost - so I believe it's going to be OK. Due to the extreme hard starting, repeated seizing up, and the fact that the unit had been out of service for so many years, I won't consider it healthy until it has a few months running on it. But it is looking more hopeful than before!
They have cabinets for both units. The CA has been in the family for years. The FEA was bought for $5 recently!
Sincerely,
David
This FEA had a bad start-relay and a bad control. It also had super-rotten wiring. Its compressor is mounted differently from Paul's FEA, blocking access to the fan motor. We had to carefully bend the condenser out of the way to remove the fan motor out the front. After that, replacing the deteriorated wiring was possible. This motor is the original GE two-phase motor with an oil fill tube. Very nice design! I expected it to work and cool, which it did very nicely! It has the blue porcelain evaporator, as well.
Notice the original mount locking tag is still in place.
Nice full frost!
Then there was the very, very sick CA-2-B16. I wasn't sure it was going to make it; and it's not fully "out of the woods" yet. It was seized when it arrived. We hit it with a capacitor and no action. Then hit it with 240V and it started, but ran very clattery and with over 400 watts power demand. Then it seized again. We put the heater on it and let it percolate with the heater getting 240V and warning the oil at 80 watts. Once the oil was nice and hot, another 240V start was made. After switching to 120V it continued to run, loudly and painfully, for about 5 minutes. Then it seized again - hard.
Having seen this issue before, I laid out all the tools to drill a hole in the dome and add 2 cups of (hopefully) life-saving oil into the compressor sump. First, I broke the vacuum in the system with nitrogen. Once that was done, a neodymium magnet was placed beside the point to be drilled. A greased drill bit was used to drill the hole. This captures chips and keeps them out of the housing. The hole was then tapped to 1/8" NPT pipe thread. We looked in the housing with a borescope and the winding and all paper components were clean and not burned.
Two cups of 150 viscosity AB oil was put in the compressor via the hole. Then a brass plug was installed with Loctite. You can see the plug to the left of the line on top of the dome.
The compressor was then re-started with 240V again, and ran with rattling and high power demand. Rapid gas percolation was heard in the evaporator due to the float seat being eroded. After about 5 minutes, the oil had apparently not circulated, and the compressor started to slow down as if it was trying to seize again. It was powered off at that time.
The float seat area was then cut from the bottom of the chamber. The seat was re-cut to a round taper with a tapered grinding point, before the seat tube was re-soldered to the bottom of the float chamber.
It took another 240V boost to start up, and the horrible rattle was still present. After the unit ran for about 10 minutes, the sound began to change. The rattle went away and the unit got quiet! After running for about an hour, and lots of NCG bleeding (due to the nitrogen put in the system) we had reasonable frost on the evaporator!
Sadly, after stopping the compressor, it would not re-start unless 240V was once again applied. To attempt to remedy this, a start-capacitor was added to the circuit, and tucked in between the fins a shown below. This provided for starting normally with 120V.
The owner of these two fridges were out of time, as I would have preferred to let it run longer and continue purging. But the whole condenser was warm (but not the float chamber) and there was a good frost - so I believe it's going to be OK. Due to the extreme hard starting, repeated seizing up, and the fact that the unit had been out of service for so many years, I won't consider it healthy until it has a few months running on it. But it is looking more hopeful than before!
They have cabinets for both units. The CA has been in the family for years. The FEA was bought for $5 recently!
Sincerely,
David
One of the main reasons for drilling a hole was to do a borescope inspection of the compressor motor for any burning damage on the winding. The discharge line is in a tough position to cut and solder back, as well. 
