View Full Version : R407c change to R22

28-08-2014, 08:44 PM
Dear friends and engineers,
My company cnc machine was using a chiller system using MTZ64HM9AVE compressor using R407c *****. Now that compressor breakdown due to short winding. I already contact all suppliers at Saudi Arabia, but they can't supply it in few days. We going to lost heavy production.
In saudi arabia, I still can find same size compressor MT64 but using r22 *****. Is it possible for me to buy and replace to the system? Sice is different compressor oil, I will clean evaporator and condensor as best I can and change filter dryer. My question is how the performance? I need to change the expansion valve also? Please guide me.

Glenn Moore
28-08-2014, 11:58 PM
Simply drain the mineral oil from the new MT64 compressor and then refil it with New Polyoester oil . You need 2 Litres of POE oil for an MT64 machine. This will make the MT64 into the required MTZ64 . The Z denotes it has POE oil in it.
Then simply refit to the system and evacuate , and charge the system with R407C
I have done this many times without problems.
You can drain the oil from the new MT64 compressor by carefully laying the compressor on its side and draining the oil from the suction connection , or otherwise remove the oil level sightglass and drain the oil . If you remove the sightglass you must use a socket tool not a monkey wrench or you will crack the glass.

29-08-2014, 08:18 AM
Installed both MTZ and MT 64's on R22 and R134a. ( R22 systems were belt drive so original gas was saved.) My MT's didn't have an oil glass. 32 grade synthetic oil and an oil separator if pipe run is over 10 metres...Just to be sure.
EDIT: Oh, a burn out. Solid core suction line burnout drier needed. Oil acidity/ contamination test will determine if a flush is necessary.