8 pistons york compressor

[veleztms]

Guys,
Need help I have a 12 years old york water chiller model:ycaj98-xv6, this chiller has (2) 8 pistons compressor model: jf843-v46. The thing is that recently we replace one of the compressors and the new one comes with 3 solenoid valves, the old one has only 2 solenoid valves from factory. Apparently 6 pistons are working full load and the other 2 with no load. We assume that the 3rd solenoid valve is fully energized. Other thing is that the compressor is working %FLA 62 constant with no step change. What should I do in this case?

[bertoh]

if you still have old comp, put the handhole cover with two unloaders onto new comp. but it should not matter, it takes an energized solenoid coil to UNLOAD each of those unloaders. if you dont have that third coil wired back relay board, then you have 4 permanently loaded cylinders and 2 stages of unloading of 2 cylinders at a time. you need as much as 60 psi oil press diff to operate the unloaders. you should see with amprobe change as it loads.
or you have busted up something inside.
ps if you change handhole covers use the right gasket or you wont load up either

[Carsten]

yep, i would do like bertoh

[gotparts90]

when it starts up all the cylinders become loaded until you apply power to unloader to unload cylinders. The extra unloader is do to lazy people in my shop and in your office not getting to the the tech-YOU and asking is it 1,2,or 3 unloaders on that unit. the old model number was most likely lacking unloader number info. I bet any money if an unloader is stuck its dirt stuck in the cover plate the unloaders are mounted on or in the valves that came from the plate.

[bruiseandy]

MAybe you should get some more training and experience before working on chillers. Guess it's harsh but who will they blame when it takes a turn south? If you just told them to hire a mechanical contractor to check it you alleviate that concern.