Saving a stuck CA-2-B16 - NCG bleed, start cap, overload...
Jan 14, 2023 16:43:57 GMT
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Post by turbokinetic on Jan 14, 2023 16:43:57 GMT
As we've seen here quite a few times, the CA machines have a tendency to become stuck or seized up over time. This is due to the design of the compressor and GE's choice of methyl formate refrigerant. Over time, the methyl formate breaks down and releases non-condensable gases into the system. This over-pressurizes the compressor and causes cumulative damage over time. Often this will manifest its self as random starting problems and overload breaker tripping. If the excess pressure is removed at this point, it may continue to work for years.
In this video, I perform a non-condensable gas purge, assisted by heating of the compressor oil before-hand. Once this process is underway, the compressor was then started using a slightly boosted voltage from a variac. While it was running, the factory recommended NCG bleeding process was continued until the entire condenser and float chamber were warm.
Knowing how the CA machines are; once the machine is worn, it may occasionally have starting difficulties. One of two things will happen. Either, it will get worse and eventually fail altogether; or it will establish a new wear pattern and get easier to start as time passes. To help mitigate this, I made two concealed modifications. One is the addition of an auto-reset overload breaker to the wiring. This is hidden behind the relay and will break the power to the motor if a start fails. It will break the power much more quickly than the factory overload does. Also, this will prevent wear and tear on the factory overload. If the machine has a hard start, the auto reset overload will re-try to start after a moment. Typically this will work, and it will start on the second try.
The other hidden modification is a start capacitor. This will give additional starting torque to the motor so that each start will be more likely to be successful. This is also hidden inside the condenser area behind the relay.
The video has more details. Hope you enjoy it!
Sincerely,
David
In this video, I perform a non-condensable gas purge, assisted by heating of the compressor oil before-hand. Once this process is underway, the compressor was then started using a slightly boosted voltage from a variac. While it was running, the factory recommended NCG bleeding process was continued until the entire condenser and float chamber were warm.
Knowing how the CA machines are; once the machine is worn, it may occasionally have starting difficulties. One of two things will happen. Either, it will get worse and eventually fail altogether; or it will establish a new wear pattern and get easier to start as time passes. To help mitigate this, I made two concealed modifications. One is the addition of an auto-reset overload breaker to the wiring. This is hidden behind the relay and will break the power to the motor if a start fails. It will break the power much more quickly than the factory overload does. Also, this will prevent wear and tear on the factory overload. If the machine has a hard start, the auto reset overload will re-try to start after a moment. Typically this will work, and it will start on the second try.
The other hidden modification is a start capacitor. This will give additional starting torque to the motor so that each start will be more likely to be successful. This is also hidden inside the condenser area behind the relay.
The video has more details. Hope you enjoy it!
Sincerely,
David
https://youtu.be/OpfnLNV5AjY
