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Miked1
03-03-2015, 06:27 AM
I have been called in to service a York DXS 24 compressor installed on a YCAS chiller. The compressor starts up okay but does not load. While running the discharge temperature keeps increasing until I shut down the system at about 90 Deg C discharge temp. The standing pressure at present is about 7.5 Bar. After starting, the suction drops to about 5 Bar and the discharge goes up to 12 Bar. The oil pressure is about 11.5 Bar. I have replaced the loading solenoid valve and coil and the oil filter. On the side of the compressor there is a large plug which houses an oil non-return valve. This valve has an arrow showing oil flow direction. I spoke to a York Tech who said that maybe the valve was installed in the wrong direction. I turned the valve around but still no difference. Has anyone else had a similar problem and what do I need to check and do to get this system running correctly. This chiller is installed in a Data Centre so I need to resolve this problem soon.
hookster
03-03-2015, 07:29 AM
High Mike1
You could have a slide problem i.e. broken slide valve return spring. Do a FLA test it looks like you are not unloading.
HVACRsaurus
03-03-2015, 07:59 AM
Do a Google search using the following text;

york form 230.10 m1 804

The top few results relate to similar issues..
Miked1
03-03-2015, 11:38 AM
Thank you Hookster and HVACRsaurus
The compressor is definitely unloaded as I am drawing minimum current on start up. I have printed the manual from the web and will trouble shoot accordingly tomorrow.
piewie
08-03-2015, 07:32 AM
Hello Mate
Tell us more! What was the temperature of the chilled water? You say you you have changed the loading solenoid coil, valve and oil filter, why? Had the coil failed? Have you checked the coils to see if you have power on them when you running? Have you checked if you have power on terminal 17&18 on relay output board 2? Have you tried manually loading with a magnet? Have you checked if there is a change of state on the unloading solenoid? Lift the coil and check if the shaft of the solenoid lifter is ok.

Let us know how you go.:)