jweins1
13-03-2011, 12:24 AM
Hello All,
We are working on a residential split system AC in south florida. 10 year old carrier split 3.5 ton on R-22.
Here's the history.
We had a dirty coil, causing high head and low suction pressure and freeze ups. Pumped down system, removed coil and did a coil cleaning. Reinstalled coil, pressure tested, vacuumed to 500 microns, released refrigerant charge and all was ok. Pressures were normal and system operated fine in cooling for 3 days.
We then received a call from the client for no cooling. Found liquid line cold and suction line luke warm. Put on gauges and found 120 psi oin high side and 20 on low side. Onsite tech figured he had a leak, so charged a couple of pounds of refrigerant but saw NO CHANGE on high or low side. Recuperated the charged refrigerant. Found discharge line between the compressor and the condenser coil hot, the condenser was cold. the only way that he was able to get the pressures normal were by turning off the condenser fan. The outdoor temperature was mid 70's. Indoor temperature was about 80
So, here's what I think the possible culprits may be, but am looking for some help, suggestions, expertise...
1. non condensibles somewhere in the capillaries of my condenser or in the compressor?
2. Restriction in the condenser?
3. Bad discharge valve on the compressor (reciprocating-hermetic)?
Please give help advice.
JBW
We are working on a residential split system AC in south florida. 10 year old carrier split 3.5 ton on R-22.
Here's the history.
We had a dirty coil, causing high head and low suction pressure and freeze ups. Pumped down system, removed coil and did a coil cleaning. Reinstalled coil, pressure tested, vacuumed to 500 microns, released refrigerant charge and all was ok. Pressures were normal and system operated fine in cooling for 3 days.
We then received a call from the client for no cooling. Found liquid line cold and suction line luke warm. Put on gauges and found 120 psi oin high side and 20 on low side. Onsite tech figured he had a leak, so charged a couple of pounds of refrigerant but saw NO CHANGE on high or low side. Recuperated the charged refrigerant. Found discharge line between the compressor and the condenser coil hot, the condenser was cold. the only way that he was able to get the pressures normal were by turning off the condenser fan. The outdoor temperature was mid 70's. Indoor temperature was about 80
So, here's what I think the possible culprits may be, but am looking for some help, suggestions, expertise...
1. non condensibles somewhere in the capillaries of my condenser or in the compressor?
2. Restriction in the condenser?
3. Bad discharge valve on the compressor (reciprocating-hermetic)?
Please give help advice.
JBW