Sanyo Hermetic Compressor

[hos]

Hi all, just have a question on a Luke chiller(water cooled 2 comps) running on R-22 with liquid line solenoids each stage, the controls just got replaced with a ddc controller from original. The chiller has 2 sanyo compressors, didn't take down the model number but it is either a ck600 or ck 800, has 3 heads, and on the side of the crankcase there are 4 unloader solenoids. Ok on start up of the compressor with no solenoids energised the compressor would run but it did not pump any gas, it went out on oil pressure after 1 minute due to oil safety. We started it again and brang in the first unloader(I think its a oil pressure valve), then the chiller began to pump some refrigerant and then bringing on the other 3 solenoids and fully loaded up the chiller. Then backed it off again and unloaded where the first solenoid stoped the compressor pumping gas.

Ok my question is, is the first solenoid an oil pressure solenoid to allow the compressor to start unloaded, then when it comes in, it allows oil pressure up to the galley in the heads where it brings in the valves for first stage of loading?

The system run ok when loaded up 450kpa, unloaded it would rise up to 580kpa, superheat was good.

[danphillips]

I work on a similar Luke Chiller with a ck600 and ck800. This chiller starts with the first stage loaded (top right solenoid valve)...this is standard I guess because there is 0 nett oil pressure when no pistons are pumping and thus going out on oil safety??