# Condenser not equalizing after cycling off



## a.man1302 (May 12, 2014)

It is a 5 ton Carrier straight cool condenser... Unit tripped breaker... Dual cap is good, RLA are good, P/T on gauges are normal... Only thing I noticed is that the pressures are not equalizing when condenser shuts down. I'm thinking bad TXV... Any thoughts?


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## CWO4GUNNER (Aug 18, 2014)

If the system is other wise working when running it should be passing vapor. The TXV should be making enough noise so that you can hear it especially when the compressor shuts down it is still equalizing for a few seconds. If not try rapping on it gently, its a long shot but it might get unstuck, Otherwise if its adjustable you'll have to mark the position exactly and try minutely adjusting it to see if you can get it working. Otherwise if it is the TXV sticking you'll have to replace it.


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## beenthere (Oct 11, 2008)

It may be a balanced port TXV. They don't equalize when the condenser shuts off.


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## zappa (Nov 25, 2011)

beenthere said:


> It may be a balanced port TXV. They don't equalize when the condenser shuts off.


Are there any advantages to this type? Does it cause harder compressor starting? Just curious....


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## Done That (Apr 28, 2011)

Balanced port is less likely to hunt at low load conditions, and are often used with special charges to create "wide range" TEV's.


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## beenthere (Oct 11, 2008)

zappa said:


> Are there any advantages to this type? Does it cause harder compressor starting? Just curious....


They help the A/C reach its SEER rating. Single phase Recip compressors require a hard start kit when a balanced port TXV is used.


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## a.man1302 (May 12, 2014)

it is an internally equalized TXV


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## beenthere (Oct 11, 2008)

a.man1302 said:


> it is an internally equalized TXV


Whether a TXV is Internally or externally equalized, has nothing to do with the system/TXV allowing the system to equalize in pressures after the system shuts off. It only helps the TXV by equalizing the pressure drop through the evap for regulating the amount of refrigerant fed to the evap. An internally equalized TXV should only be used on single row evap coils.


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## zappa (Nov 25, 2011)

a.man1302 said:


> it is an internally equalized TXV


Have you heard about the recent problems of a brownish goo clogging up TXV valves? A lot of people in the industry are still trying to figure out the cause but it's usually on units that have been installed this year and up to 3 ton.


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## biggles (Jan 1, 2008)

if there is no anti-cycle time delay within the stat or out on the 24v going in.... the breaker is tripping against that pressure.so before the unit can equalize your getting another call for cooling....does the suction rise at all? run the unit with gaiges on it shut the condenser off and sit there and time out how long it takes for that suction to climb ....what Freon are you running?


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## a.man1302 (May 12, 2014)

its an R-22 system... Suction pressure stays at around 70 and head pressure stays around 250 after shutdown... The pressures stay this way for a long while after cycling off


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## biggles (Jan 1, 2008)

you need to shut the condenser OFF and see how long it takes to somewhat balance out to around 150psi and the unit cools the house to setpoint


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## a.man1302 (May 12, 2014)

Beenthere would a time delay be the best solution to the problem?


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## beenthere (Oct 11, 2008)

a.man1302 said:


> Beenthere would a time delay be the best solution to the problem?


If it doesn't have one now, or have a thermostat with a delay. Then adding one would help a little. You will probably need to install a hard start kit on it.


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## a.man1302 (May 12, 2014)

If a system is not equalizing, is the TXV a good culprit? What else would cause this issue?


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## Doc Holliday (Mar 12, 2011)

txv or any other metering device, filter drier and or valves.


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## beenthere (Oct 11, 2008)

a.man1302 said:


> If a system is not equalizing, is the TXV a good culprit? What else would cause this issue?


Balance port TXVs are not suppose to equalize. So swapping out a balance port TXV with another balance port TXV won't make it equalize.


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## a.man1302 (May 12, 2014)

The TXV in question is not a balanced port type... Doc, when you said valves, did you mean the compressor valves?


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## beenthere (Oct 11, 2008)

If a TXV is not a balanced port, or hard shut off TXV. Then if it is preventing the system from equalizing. The system should run in or near a vacuum on the low side when it runs.


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## HVACDave (Oct 16, 2007)

It would seem odd that the valve works properly when the unit is running, but not when the unit is shut down, typically a bad valve stays bad all the time. Even the balanced port valves will typically equalize to within about 75 PSI. It would be nice to know exactly how much equalization does occur within 3-5 minutes.


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## a.man1302 (May 12, 2014)

do you mean 75 psi between high and low side?


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## HVACDave (Oct 16, 2007)

Yes, 75 PSI press difference between high and low is pretty standard for older valves, newer design valves are running around 35 PSI.


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## HVACDave (Oct 16, 2007)

A similar situation occurred when changing from an old orfice style coil to a new txv coil, we would sometimes have to add a hard start to get the unit to run correctly due to lack of equalization in off cycle making the unit start loaded instead of unloaded.


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## NitrNate (May 27, 2010)

HVACDave said:


> A similar situation occurred when changing from an old orfice style coil to a new txv coil, we would sometimes have to add a hard start to get the unit to run correctly due to lack of equalization in off cycle making the unit start loaded instead of unloaded.


yep happened to me. went to a more efficient txv coil and the compressor would only start if it had about 45 minutes to sit and equalize. anything less than that and it wouldn't kick on. added a hard start kit and has been running fine for several years.


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