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You are watching: High suction pressure low discharge pressure


Hi all,I"m hoping to gain more insight concerning an worry I"m having with among my central AC units.I have what I think are two similar Rheem, 3 ton, 12 Seer, role compressor, R22 setups.The model details on the unit which recently stopped cooling:- Condenser Model#: RAMB-036JAZ- Evaporator Model# RCBA-3765GG21 (Piston size 65)The Condenser pan runs fine. Suction line shows up to it is in ambient temperature.I put gauges ~ above the unit and also came up v 120 Suction and 130 Discharge. External temp was 90 degrees and also approx 40% humidity. Suction heat temp was 89 degrees.I additionally checked the unit that seems to be working fine and saw 68 Suction and also 250 Discharge. 48 levels
the suction line.I execute not listen the characteristic compressor hum/buzz top top the non-cooling unit.I cleaned the condenser coils 2 years earlier and they still show up to be cost-free of dirt/debris. It"s hard to be 100% certain as I have to remove the entire housing in bespeak to examine thoroughly.My research study is suggesting a negative compressor or faulty development valve.Can anyone provide any understanding on what I must test or look because that to troubleshoot further? I"m guessing I need to verify strength to the compressor and also determine amperage draw.........?
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it sounds favor u"re top top the best track.with a piston there"s no expansion valve.would pump down the unit to check the compressor if it"s running however not pumping.
Is the a warm pump? when reversing valve can cause the refrigerant no to move through the system. Being almost out the charge, and also off as result of an open up low push switch is probably what you have. Ns say this since your push on the high next is much less then R22 must be there is no the unit running, as soon as it is totally charged.
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Thank you because that the replies.U-1234: ns did not execute a pump under as I"ve never ever done one.I the review the procedure a couple of times ~ above YouTube and also it seems fairly simple. What have to I look for specifically? would it be that the compressor wont be able to adequately suck every the refrigerant to the compressor and also condenser?Beenthere: This isn"t a warm pump. It"s an AC unit through the A coil end a gas-fired furnace. A Coil looks really clean, yet damn, not straightforward to access for cleaning. Would certainly a really low charge show these sort of numbers?
The compressor does not appear to be running.I also just noticed the the contactor appears to be stuck in the on/engaged position.
If your thermostat is on your contactor will stay shut also if you turn off strength yo external unit. A couple of things to look at for. When you very first turn on unit go compressor even try to start? allow us recognize so we have the right to go from there. If the tries to start but goes the end on overload, ns would examine capacitor or wiring for starters
My bad. I need to have linked the dots with the thermostat. I"m to be so focused on the pressure that i didn"t take the entire system into account.IMO, the compressor is no trying to start as soon as I interact the power (via the cutoff "switch"). However, as soon as I host my hand on the optimal of the compressor I execute feel what might be slim pulses every 20 seconds or so.Should ns swap out the capacitor anyway? i may have one i took out of company that"s quiet good.
Is that a warm pump? when reversing valve can cause the refrigerant no to move through the system. Being almost out the charge, and off as result of an open up low press switch is most likely what you have. I say this due to the fact that your pressure on the high next is much less then R22 have to be there is no the unit running, once it is totally charged.
90 degrees. How can the OP also have numbers together low as was reported? I would certainly think the unit would have to be virtually empty of fee to have actually numbers this low.... As I understand it (studying because that my 608 T2 exam, BTW ), if ns have even a couple of ounces of R22 in a container at 90F, the pressure should be 168..... To be below that ns would have to virtually no fluid in there. Something doesn"t quite include up......
Couldn"t hurt to swap out capacitor. You require to check wiring come compressor together if it to be trying to start and couldn"t start it would certainly be hot. Your fan motor is to run right? Sorry actual busy appropriate now, will have some slack time later
No trouble at all. I appreciate any assist I deserve to get.Fan motor is running. Compressor not warm as i tested after leaving the mechanism off for several hours.I"ll view if i can uncover that capacitor.
90 degrees. How deserve to the OP also have numbers together low as was reported? I would certainly think the unit would have to be practically empty of fee to have numbers this low.... As I know it (studying because that my 608 T2 exam, BTW ), if ns have even a couple of ounces the R22 in a container at 90F, the pressure have to be 168..... To be below that i would need to virtually no liquid in there. Other doesn"t quite add up......
You deserve to have a lb of R22 in a 30 pound party at 90°F, and have no fluid in it. And it will of food be at a pressure reduced then the saturation temp.
When posting in certain forums, discovering your location will aid others give much better feedback/advice/solutions to her questions.
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ohm out the compressor windings.C to S, C to R, R come S need to equal resistance of (C come S) + (C come R)resistance from all of these terminals come the compressor casing need to be infinity.make certain power is being used to the compressor before you change out parts. Capacitance have the right to be measure if u have the tool.if not and everything rather checks the end u have the right to pick up a capacitor and also a cheap hard-start kit. If the bearings are siezed/stuck the hard-start can carry out the kick essential to acquire the compressor to revolve over.
Really require a meter in ~ this point. Yet it won"t ache to shot capacitor since you have actually one. I wouldn"t buy something yet. Check your wiring ( with power off) view if over there are any kind of breaks. Look at the Orange wire going native the capacitor come the contactor, castle burn increase sometimes. If you might talk part readings we probably might guide you through it
Thank you all!Whipped the meter out and also the resistance all confirm out. No longer have a capacitor checker or the attribute on any kind of my meters so I"d need to find one more component come swap out.I somehow managed to find the box of extra AC maintenance parts and also happened to have a new twin run capacitor for this unit.Plugged she in and also the unit is working again. I"ve replaced capacitors before but because of a failed condenser fan. Guess one half of the capacitor was working and also the various other wasn"t.I"ll put gauges top top it morning to check out what I"m at and report earlier as i may have actually a pair questions.Right now I"m walking to have a beer or two and deliver a instead of fuel pump to one of my buddies for his boat. Great I might buy ya"ll a couple of rounds as well.

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excellent.when u put gauges on check the suction line temperature too, post. Out temp, wetbulb return temp, supply temp would certainly give great snapshot of how it"s cooling.
OK, results are:Outside temp: 87Outside humidity: 33 (approx)High next pressure: 225Low next pressure: 64Suction line temp: 48FLook good?BTW, with the unit turn off the pressures read similar to what was initially posted. Is that normal?
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