Trane RTAC High oil temp

[Bash1803]

Hi,

I have a Trane RTAC 140 which inermittently trips on high oil temp.
I have reset and run on full load in the past and could see no obvious issue. Could this be linked to a pary load condition?

Not really sure where to begin...... any advice would be most appreciated.

Many thanks

Bash

[goshen]

Hi
first of all check the sensor !!then check your load,what control do you have? if it is ch530 then this is the diagnostic:The respective oil temperature as supplied to the compressor, exceeded 200°F for 2 consecutive samples or for over 10 seconds. Note: As part of the Compressor High Temperature Limit Mode (aka Minimum Limit), the running compressor’s female load step will be forced loaded when its oil temperature exceeds 190F and returned to normal control when the oil temperature falls below 170°F.

good luck

[Bash1803]

Thanks for that Goshen, but am ruling out the sensor, and potentially a blocked filter as it happens very intermittently, it ran today with no problem.

I reckon it may have something to do with the setpoint as the unit was set to 7'C. I have read that these machines control on return water, so if this is the case, the cold water may caise the unit to run on a very low load, not producing enough liquid to effectivley cool the comps.

Can anyone;

1. Tell me if I am talking pants and
2. Confrm whether these units (Trane RTAC 140) control on flow or return

This unit uses the old adaptive touchscreen controller.


Many thanks

Bash

[Grizzly]

Hi. Bash.
1 you are not talking pants and a low load condition could wel be the issue.
As the control system (CH530) will try to load the comp inan high oil temp situation.
2. They control on a leaving water (Flow) stratergy!
Have you concidered a reduced flow option?
Grizzly

[goshen]

Hi
as grizzly stated:
5.Press the AUTO key. If the chiller control calls for cooling and all safety interlocks are closed, the unit will start. The compressor(s) will load and unload in response to the leaving chilled water temperature.

if you need the manual mail me
good luck

[install monkey]

if you want to talk through ur undies,go for it!!!
the unit has the option to control on flow or return depending on settings on the adaptive control- check the bottom 1/4 of the condenser as this is ur oil cooler section, check all fans operate, had 1 with 1 inverter goosed and 2 fans siezed- not bad as it had 6 on it,

Thanks for that Goshen, but am ruling out the sensor, and potentially a blocked filter as it happens very intermittently, it ran today with no problem.

I reckon it may have something to do with the setpoint as the unit was set to 7'C. I have read that these machines control on return water, so if this is the case, the cold water may caise the unit to run on a very low load, not producing enough liquid to effectivley cool the comps.

Can anyone;

1. Tell me if I am talking pants and
2. Confrm whether these units (Trane RTAC 140) control on flow or return

This unit uses the old adaptive touchscreen controller.


Many thanks

Bash

[install monkey]

http://www.mediafire.com/download/de...N_02172011.pdf
rtac
http://www.mediafire.com/download/ca...m_controls.pdf
ucm controls

[CV_Geardrive]

Hi Bash,
Check if your fans are working properly and check if the condenser needs chemical cleaning.
Check the water flow in the evaporator if it is within limits.
If the evaporator approach is very high then the vapor is not as dense as it should and this vapor must also absorb all heat related to motor, compressor and oil.
If you have big approach and the expansion valve is quite close then you probably have lot of oil in the evaporator and the oil distillation (return) line filter must be checked.
If you have big approach and the expansion valve is wide open (>80%) then you may have shortage of refrigerant.
Usually in full load you should have 5 to 6C difference in water but I have seen units with 7 to 9C running without problem.
If the liquid level sensor is not operating so well it may starve the evaporator and you may have the problem you indicating.
If in the past someone open the refrigerant circuit and lost some oil and never filled it up then you may also have the same problem.
All these in respect that the oil temperature sensor is OK.
As a rule of thumb, if the difference between discharge pressure and oil pressure is much more than 1 bar then you may have a blocked oil filter.
Hope it was not too complicated.
Regard,
CV

[serviceman]

I have changed the oil this machine?