return oil to carlye compressor

[bbdd1]

I have a 38aqs012 and a 40rr. Superheat is 35,subcooling
is 30.psig low side is 47,high side is 180.outdoortemp
was 72,liquid line temp was 72,suctin line temp was 63.
Wet bulb was56,dry bulb was 46,indoor temp was 69,supply
was 59,return air was 73.Proplem is tripping on oil pressure
switch,oil is not getting back to the compressor,does anyone
have any suggestions.thank you in advance.

[fat eddy]

I am not familiar with those model numbers, but I would be curious as to how the liquid line could be 72 when the outdoor air is 72 also. Unless this unit is not an air cooled condenser.

Then you said that your wet bulb was higher than your dry bulb, this can not be.

If I can decipher what you are trying to say from what you are actually saying I would be thinking that you have a restriction problem somewhere.

There are a lot of problems with your measurements and the way that you have written them, please repost with better info.

Type of unit, correct pressures and temps, what type of oil control.and when does it trip.

[Wild Leg]

How is wet bulb temp higher than dry bulb?

[bbdd1]

Sorry,dry bulb today was 70.Pressures were 58 suction
275 head.Unit is a split carrier heat pump, runs about 10
minutes.I did some more checking and i think i will
replace the oil solinode.

[airworx]

overcharged and probrabaly bad txv or restricted drier.

30 degree subcooling means your overcharged. that with a low suction and high superheat means evap is starving.

repair restriction and remove refrigerant.

[hvac3901]

no or low oil return?

do a blow by test. check for a pressurized crankcase.

[wasp]

You did not mention, but did you check to see if you had power to the solenoid coil on the oil return? Or if there was a relay that energizes or de-energizes to put power to the coil? Hope you're not adding oil every time on oil pressure failure.

[Dowadudda]

Originally posted by airworx
overcharged and probrabaly bad txv or restricted drier.

30 degree subcooling means your overcharged. that with a low suction and high superheat means evap is starving.

repair restriction and remove refrigerant.

AND THAT BEING THE CASE< WHERE DO YOU SUPPOSE ALL THAT OIL IS HIDING AT?

Dude. I just friggin love guys that understand subcooling and superheat.

[joeywpittman]

?is this a new install?
is the suction line sized properly?
when you replaced the oil solenoid valve, cut it on the accu. size and measure the amount of oil that pours out. if it is over half of the systems oil charge than you found the problem. if no oil comes out the oil is hiding somewhere else.

[Hrdworkingacguy]

Thats cut and dry that you have a liquid restriction of some sort...A liquid line the same as the ambient means the liquid is stacking up in the condenser and has no heat to remove(due to a starved evaporator) that unit I think is a 15ton carrier split heatpump? probably has a bad expansion valve or possibly a bad connection between the bulb and the suction line...

Liquid restriction would cause an oil return problem but I have a building here in arizona with the same unit and the same problem and its related to the length of the lineset 1 5/8 suction and 5/8 liquid and the air handler is 30feet below...I think my case is a bad lineset design...:eek: