Problem Latched fault Trane RTA 125

[koekoeh]

We got problem on start Y delta, on chiller trane RTA 125.
Problem : Latched fault n Phase reversal Prot lost.

We have changed contactor all, but the problem still there.
pls advise what I have to check to solve this problem.

thanks for your help.

[CV_Geardrive]

Hi Koekoeh,
Most probably you should change all auxiliary contacts of affective compressor contactors.
If you need detailed answer please provide more data.
1. Model number. It is RTAA or RTAD or…??
2. Is this happening in both compressors?
3. What is the sequence before the unit fails? Does it start at Y and trips on transition mode or in D mode?
4. Is it happening always or only when the other compressor is in operation.
5. Etc….
In each case provide details in order to have a valid answer.
Regards,
CV

[goshen]

HI i would check the voltage transformers that provide the unit with phase rotation warning.you should also check the ct's.
good luck