RTAA080

[PACKLEADER]

Hey Guys,
Gottta Trane screw tripping on high oil temp,when you reset the diagnostic code the oil temp runs about 135 degrees and will run all day and seems to trip at night, circuit 2 starts up and runs great till it reaches setpoint then it unloads and as water temp rises the comp. then loads and suction pressure drops and saturation temp also drops and locks compressor out,checked all sensors calibration,removed pill filters,all silenoids are operating properly,installed male unloader piston kit,changed oil filter and liquid line core driers and cant seem to shake this diagnostic....ANY SUGGESTIONS?

[Chiller Guy]

What is the diagnostic code you are getting?

[PACKLEADER]

The controller is a clear language display and it says high oil temp comp "A" and low evap refrigerant temp ckt 2

[bowhunter21]

For the high oil temp diagnostic, are all your condenser fans operating. I assume the consensers are clean? And for circuit 2 check the sensors to ground any reading at all replace the sensors!

[Healey Nut]

First off do all the fans work and are the coils clean especially at the top 4" thats where the oil cooler passes are . Compare the resistance of the oil temp sensors , obviously they would have to be at the same temp to check them . Try switching the sensors around and see if the problem follows the sensor or stays with the compressor . Make sure the connections on the sensor terminals are clean and tight ..

[PACKLEADER]

All sensors have been changed already and all fans are operating and condensor coil has been pressure washed.

[Randy S.]

Pin connections onto the boards?

These have been problematic for me, but not on the sensors.
See if they feel like they could just fall off the pins.

[PACKLEADER]

OK, Thanks for all the input............Ya'll have a great weekend

[jayguy]

did you clean BOTH sides of the "W" coil or just the outside? did you clean it opposite of air flow? that is a thick coil bank and it loves to get jammed up with debris if you clean it the wrong way. perform an oil level test on the oil separator...you may not have enough oil.

good luck.

[jogas]

did you clean BOTH sides of the "W" coil or just the outside? did you clean it opposite of air flow? that is a thick coil bank and it loves to get jammed up with debris if you clean it the wrong way. perform an oil level test on the oil separator...you may not have enough oil.

good luck.

FWIW,
When checking the oil level on an RTAA, use 3/8" hoses (adapt to 1/4" at system connections) and site glass. It's a lot quicker to find the level with the larger ID hoses when moving the site glass up and down to find the oil level.
I've worked on a couple RTAA's I wish I'd never met.
Good luck.
jogas

[bowhunter21]

If the circuit runs with no laod for a extended period of time that will also cause the oil to get hot.

[mtntom]

Every highoil temp alrm on RTAA I have seen is due to dirty coils or bad cond. fans. these machines trip on oil temp before high head. Have had sevral calls where everybody swears the coils are clean, I show up, clean the coils properly(using good foaming coil cleaner and reverse flush) They are amazed at the dirt that comes out and what do you know, the high oil temp goes away!
Low evap temp-Check your charge, water flow would probally show up on both circuits

[CaptJackSparrow]

All sensors have been changed already and all fans are operating and condensor coil has been pressure washed.

This may be your problem. The pressure wash. There is a guy in Dallas who made a pressure washer that is low pressure, high volume and cleans coils for a living. It work great! The high pressure low volume rigs are worthless in my opinion and just pack the crap a little tighter into the coil. I want to make a high volume rig but in the mean time I will be using the old fashion pink and hose. Also:
Check your subcooling. 18 to 22 at full load.
Compare UCP Cond saturation temp to actual gauge temp. ( Verifying sensor Cal)
I assume you would know to check all of the cond. fan bearings and feel the motors for overheating.

Good luck!