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BamaCool
05-12-2007, 10:50 AM
I replaced a compressor in a 14 year old Bryant package straight air unit. Not my recommendation, but owner's choice. Never saw the unit run. Install new compressor, vacuum, recharge with 7.0 lbs, per data plate, fire up unit. Everything looks good except head pressure a little high, suction pressure is right on the money. Shut down, clean cond coil, and while I was at it went ahead and cleaned evap coil. Started back up, and now head is way high. Has clean coil, plenty of air flow. Return air is 80F, ambient 86F. Suction 79psi, head 475psi. Shut down unit. Came back next day with some piercing valves to find out where the obvious blockage was. Started up unit, waited for head to build up, kept waiting, kept waiting. Never happened! I cycled the unit 5 times, works perfect everytime. Suction 79psi, head 255psi. Anybody seen this before?
ga-hvac-tech
05-12-2007, 11:12 AM
Defective gauge set... :D

Get a YJ digital... :cool:

http://www.yellowjacket.com/HVACRProducts.asp?t=HVACR&l=5&c=33&p=310
t527ed
05-12-2007, 11:18 AM
must of been some really thick water.....:D
BamaCool
05-12-2007, 03:03 PM
Gauges are fine.
ga-hvac-tech
05-12-2007, 04:27 PM
I am suer your gauges are fine, I was harrassing you. I would be interested to know what it did also. All I can figure out is perhaps there was a restriction that 'blew through'???

Please let us know if you figure it out.
OregonYeti
05-12-2007, 04:30 PM
might be water in the system forming ice in the txv? then melts after a while? But then a good evac would rule that out.
BamaCool
05-12-2007, 07:33 PM
Thought about all that, but there is no TXV or piston. It has a flow distributor. At first I thought the factory drier might have come apart, but if that was the case, the particles never would have made it through where the flow dist. enters the evap coil. Also, on the first day of working on it, the pressure would not equilize even after 30 min., which is the reason I decided to tap the liquid line in a few places. When I arrived the second day, the pressure would equilize within 1 min. every time. I think the AC ferry came by that night.
bell3156
05-12-2007, 09:13 PM
you have plugged screens , that unit may have 2 of them if it is a heat pump, the scrren may be before the piston or located on the outlet of the condensor it should look like a small bullet drier, cut it in half remove the screen and drier and install a new drier.... you have debris in the line floating around.