blinker0
Registered User

Yep. When 502 started to become a issue Alot of lazy Techs would just change the refrigerant. And not drain and flush the system. And just recharge then charge the client alot of money for work not done properly . Needless to say compressors are expensive. So we would rebuild them if possibe Still depending on the damage minimum 5000 to rebuild them. Thats with a client discount. To help compensate . And hope in the case of Electric driven Herms . That if locked up they didnt damage or bend the electric motors Shaft.
They recommend @ least 95% POE when converting. If using a crankcase heater 80%. But if you can achieve 80% you should be good.
Also A/B oil Can have wax separation issues below - 40C So if you have to charge 507 or 404A and you cant get the oil to atleast 80% POE run a suction line filter instead or in conjunction with accumulator
If you have a system That you are concerned with or Condenser you think contamination May have occured
http://www.amazon.com/Mastercool-910.../dp/B000HAUXLE
It is expensive But Great stuff

Yep makes sense and is exactly what I was looking for. Thats why in my test system it ran fine. Its the long term wear and tear which will become an issue.
I dont use rotaries much with r507 but when I do I drain them (based on others advice) but not really knowing why. Now I know why.