I have been asked to look at some York MTS 24S AA D46/200 semi hermetic screw compressors by a colleague of mine the screw compressors are fitted to a York YCAV 0569 fluid chiller.

I usually work on Industrial refrigeration plants mainly Ammonia and chemical plants and I overhaul large Reciprocating and Screw compressors frequently so my colleague has asked me to check out the compressor for him as it was tripping on high current when it went to full load.

On first appearence the compressor looks similar to an XJS 120 frick with some modifications to it.
When I spoke to Frick and gave them the model, serial and part number of the machine I was told by them that the model did not show up in thier system at all.

I removed the bearing cover and performed a thrust check on the machine and found the thrust clearence to be .040" different between the two rotors!!!!!! Dead machine in my books the compressor has only done 28,000 hours

Does anyone know the recommended inspection/service interval for these screw compressors?

My colleague looks after 6 of these chillers so he wants me to do a thrust check on all the machines for him to check the wear in the compressor bearings.

I am looking for any information possible for these compressors and the chiller itself.
A parts diagram of the compressor would be very useful so I could order new o'rings for the back bearing cover of the machine and new bearings if I find wear in them.

Any help would be greatly appreciated