overcharged unit freezing evap no air flow issues

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overcharged unit freezing evap no air flow issues

Postby Madmax99 » Fri Aug 28, 2015 1:53 am

Anyone please explain what is the cause and remedy for this situation.......

R-22 2.5 ton split. 30 foot line set. No air flow issues. Don't have models as of now but don't think it's relevant. About 12 years

First visit unit no cool unit mechanically running. Cleaned condenser coil thoroughly. My pressures 180/50. Did light leak detection found no leaks. Added easy seal leak stop and charged unit. Pressures 300/75, out cond 90 line temp 49°f. Little overcharged but thought it would be fine.

1 week later, Second visit breaker for condenser tripped, unit started up ran fine pressures looked fine, 5.3 amps on compressor.

3 days later, Third visit lines frozen dormant equalized pressure 75 psi, running 200/60. Checked filter, evap coil, pulled return line and back side of evap coil, checked supply lines for airflow, all with no issues. Did a quick charge on unit beer can cold and left. Thought someone (maintenance/ meth cook due to it being a rathole apartment complex) tampered with unit due to it holding pressures for a full week previously.

Did a checkup on unit next day it was running lines where mid-40's no issues.

Three days later on walkby inspection of 7 units before billing unit was frozen again. Dormant equalized pressure 70 psi did heavier leak search and on highest setting with refrigerant detector found one on evap coil.

Here's where it gets interesting. Next day in process of replacing evap coil. Lines frozen again shut down unit to pump down to condenser, refrigerant circuit tripped continuously in compressor (seals) and it would not pull refrigerant to condenser. In the process when I shut unit offf at disconnect all the refrigerant reappeared in the unit my gauges read 155 psi with the unit off and pressures equalized. Turned unit on pressures jumped up to 410/100. I evacuated the system filtering the refrigerant it weighed in at 5 lbs 6 oz factory charge is 4 lbs I'm figuring 4 lbs 8 oz with line set so it was overcharged. I refiltered refrigerant to my charge and then balanced the charge perfectly using wet bulb, dry bulb, suc pressure, line temp method of superheat which left the line at 56° and I left it like that and haven't had an issue now for two weeks. Any answers for this?
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