HVAC Site - Professional HVAC Contractors Forum banner
1 - 11 of 11 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
This unit was only 1.5 years old. Customer cannot locate Installer. Unit has variable speed blower.
Had only 11* temp drop.., 77* D.B. return (67.4W.B.)..,66*D.B.supply at plenum.
58* low side 165psi..., 275psi hi side condenser temp 93* D.B.
Tryed using subcool chart on units sticker., i believe it wanted around 342-370 hi side P.S.I. at 95* ambient.,, started adding freon nothing happen,added more,nothing!
Got caught in the old trap.,,I'll lower that a-coil temp, must of let out 3lbs + freon! STILL 58* coil temp! hi side came down about 25lbs. Still had 11* temp drop inside home. I did have temp gauge on liquid line at cond.,believe it also stayed at 89*. Had a mind freeze and left!:censored:
 

·
Registered
Joined
·
33 Posts
High suction and low head = bypass somewhere...either the reversing valve or compressor. If it's a heat pump, try switching the reversing valve a few times. If a scroll, try reversing the start and run leads at the contactor/capacitor to reverse rotation for a few seconds. If the compressor is hot, cool it down and see if that helps.
 

·
Registered
Joined
·
42 Posts
Suction and discharge seem real low for a 95 degree day.
Is the system exp valve? may not be feeding NG
Is their a strainer before the feed orifice? may be partially plugged.

I would think with 410A the suction should be double what you are getting around 118# S and the discharge should be around 418#D.
 

·
Registered
Joined
·
33 Posts
Whoa you can change the direction of a single phase compressor.?????
At least sometimes. The first time I did it was by mistake. But I had one scroll that seemed to be locked up. Did all the capacitor / hard start stuff with no success. Reversed the leads and it started running. Switched them back, and it ran normal. Go figure.:blink:
 

·
Registered
Joined
·
84 Posts
As beenthere said
Restriction in the llfd. or the liquid line valve is partly closed Note your liquid line is cooler than outdoor temp. The dryor or valve is acting like a metering device.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #11 ·
Thanks Guys,have not been back to job site yet. Couple things on posts I may clarify.., at 15.5 seer it almost has to have x-valve..,it is not a heat pump..,I did not check to see If service valves were open.., I did not see nor do a LLFD temp in temp out test. Do not know if Coleman puts a strainer in there systems. Any more Ideas appreciated.., will keep every one posted!
 
1 - 11 of 11 Posts
Top