Trane SCM Chiller controller

[Pingo]

Hi
I hope someone can help me out on a problem with a Trane chiller controller,
The chiller is a ECGCE 205 model year 1991
(I am trying to keep it running for one more year)

The chiller has 4 scroll compressors controlled by a SCM controller.

Module A works compressors 1and 2
Module B works compressors 3and 4

On my visit to the site on Monday,compressors 1and 2 are working fine but module B is not operating the compressors, no faults are being shown on the display, checked all the gas pressures, Hp switches , overloads etc etc.
all are Ok, just awaiting a signal to start from the B module.

Temperature set point is 7c and so i allowed the temperature of the water to rise to 18c to try and start the 3and 4 compressors from Module B.
But this is not doing the trick, only module A operates and runs compressors 1and 2

On the B module the Green LED light is on for the LP switch. which is the normal indication for the LP switch and show it made.

Does anyone have any service and commissioning information for the controller ? ( I have the Installation/operation/maintenance manual for the SCM)

Trane want over £3K for Module A and £2K for module B so i would like to try and repair it and save the customer a lot of money before the main project of replacing the chiller

regards Pingo

[CV_Geardrive]

Hi Pingo,
Most probably the module had HRD4 alarm which means that it’s eprom is deleted.
You can easily check to find the starts and hours of B! circuit compressors by pushing the reset button. (Check the data I sent you in your email)
If you can’t find these data but only starts and hours of A! circuit, then the module need to be programmed.
You can use the programming guide I sent you.
I suppose that selector switch in B! circuit module is set to A+B!!
Regards,
CV

[Pingo]

Hi Cv

Thanks for the information. I was going back to the site this coming week but I have found out from the office that the customer has not payed some of the earlier bills, so I will wait till the money thing has been resolved.

I think you are correct about the eprom, because when I looked for the information by using the reset button a lot of the information is missing.

CV. Would the faulty eprom be in the master module A or in the B module ? and would the customer have to replace the complete module.

regards Pingo

[CV_Geardrive]

Hi Pingo,
The eprom is at main (A!) module.
No need to replace module. If you like you can install a filter in the 12VAC supply.
Regards,
CV