garyjh24
04-06-2012, 01:15 PM
Hello Everybody,
I have a Mitsubishi VRF system, Model No PURY-P250YHM-A, Connected to 8x Floor Standing PFFY-P32VLRM-E.
Recently had a problem with 1x Indoor Unit Not Cooling/Heating. Performed some checks & suspected Expansion valve was not working correctly. Replaced the head first, still no effect so replaced the body also.
Unfortunately when replacing the expansion valve body I was not present, but I was informed after the work that the strainer before the expansion was found heavily coated in oil. The engineer cleaned the strainer and installed the Expansion valve. Once again upon commissioning we still had no cooling/heating from the evaporator coil.
Since the above we have now done various works, including replacing the solenoid valve heads on the BS box (from a spare port) and installing the unit’s pipework onto a free port, still no better.
Obviously there is major issue here, the evaporator coil seems like it is full of oil.
The above has been going on for a little time now and the customer is now becoming very unhappy. So much so we planned to remove this Unit, attach the pipework to another free port on the BS Box and install one of the other units on the circuit in its place.
With the faulty unit removed and the ¼ & 3/8 pipework removed from the BS Box we tried to flush the pipework with nitrogen before attaching the replacement unit. We found the ¼ liquid line completely blocked, tried to put 200PSI of nitrogen pressure down the pipe, no discharge from the other end, tried 300psi, 400psi, still nothing from the other end (never come across a blockage like this before so even belled the pipework out to make sure we’re definitely testing the right pipe).
I would assume from such a blockage we have a damaged ¼ pipe or a solid oil/debris blockage.
We plan to attend site Thursday to get access to this pipework (its all located under the floor). Now hopefully we will find the pipework damaged, thus allowing us to see what caused this problem, but if not would anybody have any kind of idea what could have caused this?
The condenser is located on the roof, and this system is installed on the top floor, therefore no real drastic pipe runs. Id assume if oil traps etc needed to be installed all the units on the system would have been affected.
If we do find the cause of the problem is there anyway we can clean the oil filled evaporator coil so we can reuse?
Your thoughts and help would be most appreciated.
I have a Mitsubishi VRF system, Model No PURY-P250YHM-A, Connected to 8x Floor Standing PFFY-P32VLRM-E.
Recently had a problem with 1x Indoor Unit Not Cooling/Heating. Performed some checks & suspected Expansion valve was not working correctly. Replaced the head first, still no effect so replaced the body also.
Unfortunately when replacing the expansion valve body I was not present, but I was informed after the work that the strainer before the expansion was found heavily coated in oil. The engineer cleaned the strainer and installed the Expansion valve. Once again upon commissioning we still had no cooling/heating from the evaporator coil.
Since the above we have now done various works, including replacing the solenoid valve heads on the BS box (from a spare port) and installing the unit’s pipework onto a free port, still no better.
Obviously there is major issue here, the evaporator coil seems like it is full of oil.
The above has been going on for a little time now and the customer is now becoming very unhappy. So much so we planned to remove this Unit, attach the pipework to another free port on the BS Box and install one of the other units on the circuit in its place.
With the faulty unit removed and the ¼ & 3/8 pipework removed from the BS Box we tried to flush the pipework with nitrogen before attaching the replacement unit. We found the ¼ liquid line completely blocked, tried to put 200PSI of nitrogen pressure down the pipe, no discharge from the other end, tried 300psi, 400psi, still nothing from the other end (never come across a blockage like this before so even belled the pipework out to make sure we’re definitely testing the right pipe).
I would assume from such a blockage we have a damaged ¼ pipe or a solid oil/debris blockage.
We plan to attend site Thursday to get access to this pipework (its all located under the floor). Now hopefully we will find the pipework damaged, thus allowing us to see what caused this problem, but if not would anybody have any kind of idea what could have caused this?
The condenser is located on the roof, and this system is installed on the top floor, therefore no real drastic pipe runs. Id assume if oil traps etc needed to be installed all the units on the system would have been affected.
If we do find the cause of the problem is there anyway we can clean the oil filled evaporator coil so we can reuse?
Your thoughts and help would be most appreciated.