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Draco
16-09-2009, 10:16 AM
hi all,
i repaced a compressor on a 24000btu split unit,
the problem i have at the moment is when the unit is in cooling & i am pulling R22 into the system, the low side is on 410psi, the pipes are still frozen, so i must add more gas for the pipes to sweat, but when i turn off the unit the low side gauge reaches 1500psi.
if i put the unit to heat mode the pipes get so hot, & the compressor kicks out, there is no air in the system & is pure R22, any ideas:mad:

nike123
16-09-2009, 10:46 AM
1500 psi means that you have bomb!
Check again your readings!
Is it PSIA or PSIG?
Did you replaced compressor with original one or with some kind of replacement of different make and model#?
What is expansion device?
Did you find what is killed previous compressor?
Charge that unit using scale and weight at nameplate!!!

Shibhrac
16-09-2009, 11:39 AM
It's better if you use another gauges and reread the pressure as the given readings sound unrealistic ,also get the RLA. , the LRA ,voltage , and the ph of the new and the old compressor from the name plates .

Draco
16-09-2009, 03:02 PM
gauges were not too health, changed gauges, on cooling l/s =50 psi - 3.2 bar. unit off l/s = 144 psi - 10 bar.
still to high, pipes still frozen, evap coils still freezing. going to recover the gas & start again, compressor is exactly the same as old comp, the other comp was miswired & burnt out.

nike123
16-09-2009, 03:17 PM
gauges were not too health, changed gauges, on cooling l/s =50 psi - 3.2 bar. unit off l/s = 144 psi - 10 bar.
still to high, pipes still frozen, evap coils still freezing. going to recover the gas & start again, compressor is exactly the same as old comp, the other comp was miswired & burnt out.

Is your pressures absolute or relative (psia or psig)?
Expansion device type?
Indoor air in and out DB and WB temperatures?
Suction pipe temperature?
Did you charge it by nameplate + additional charge for pipe length higher than unit is precharged for.

flarenut40
16-09-2009, 11:43 PM
Hi Draco
1st thing I would do is look at the indoor unit and see if there is any reason the evap is not getting good heat exchange between the Refrigerant and the Air - ie Blocked filter, blocked coil fan speed too low.
I would expect the gauges to read around HS 15bar, LS between 4 and 5bar depending o the ambient temp and the room temp.
Like Nike123 said if you measure/calculate and weigh the charge into the system then you eliminate any guess work and you know something else is wrong, and problably contributed to the failure of the original compressor. Good Luck

udarrell
20-09-2009, 07:51 PM
It sounds like an extremely low heatload on the evaporator.

I would not be running it that way until you locate & eliminate the cause, it could damage the new compressor. - Darrell

Magoo
21-09-2009, 12:44 AM
Did you weigh in the correct refrigerant charge as per manufacturers label on the outdoor unit.
Quite often when stopped the reversing valve will unload and equalise system for low starting torque requirements.
Double check your service gauges as being accurate.
magoo