24000Btu Rotary Compressor overheating

[tudorice]

Hi, i recently was ordered to attend to a midwall split unit that wasnt working. Compressor was not pumping. Changed the compressor, pulled a vacuum, charged unit and unit ran for about 5 mins then compressor stopped and was very hot. The unit is a Samsung. I thought there might be a blockage by the capilliary tubes, i flushed the whole unit, but there wasnt any blockages. Discharge pressure was around 150 psi and suction was going into a vacuum. Thought that i had undercharged unit but that wasnt the case. Please help. The unit is all single phase 220v. And its a R22 system.

[monkey spanners]

I have seen some strainers block up on basic R22 splits, i could blow through with nitrogen ok but once i put some R22 back in it blocked up again.
In the end i replaced the strainer with a small 032 drier as the system was a cooling only unit and it worked ok.
I think it is because of the oil going waxy.

Jon

[Brian_UK]

Service valves fully open ?

[goshen]

Hi, i recently was ordered to attend to a midwall split unit that wasnt working. Compressor was not pumping. Changed the compressor, pulled a vacuum, charged unit and unit ran for about 5 mins then compressor stopped and was very hot. The unit is a Samsung. I thought there might be a blockage by the capilliary tubes, i flushed the whole unit, but there wasnt any blockages. Discharge pressure was around 150 psi and suction was going into a vacuum. Thought that i had undercharged unit but that wasnt the case. Please help. The unit is all single phase 220v. And its a R22 system.

Hi
is the 4 way valve ok???
check the strainer!
good luck

[Frostyguy]

Ya, I was going to say, check the reversing valve as well.. You have a restriction, use process of elimination even if you have to install service ports at key spot in suction line.
If the compressor gos into an immidiate vacuume its probably the four way valve.
OH... lol, when you replaced the compressor did you use a new piece of hard drawn copper and forget to remove the rubber plug????

[tudorice]

hey guys thanks for the help, I checked the wiring again on the compressor terminals (thinking that maybe i had got them the wrong way). Checked again for blockages, found none, its a cooling only machine, doesnt have any strainers. And i found the problem. Which i am very embarrased about. On some samsung remotes there is a built in thermometer and u have to adjust the temp to see the set point temp. whilst i was away someone adjusted it to above the room temp, so the compressor wasnt running for long enough, and hence why i couldnt charge the unit properly, leaving me to think that there was enough gas in the system and that there might be a blockage or that the wiring on the compressor was wrong. Big my bad.

[monkey spanners]

Pleased you found them problem!

Jon

[Brian_UK]

Glad problem is resolved but - you should really weigh in the gas charge if possible; it's much safer.