York YD Problems

[aceairman]

I service and maintain a high profile contract and I need some advise, guidance and assistance.
I have (4) 2500 and (2) 1250 ton York YD's on site. I have been maintaining these guys for three years. I have encountered a fair amount of problems that I have been able to review the manuals and work out ok but last year I had a VGD shaft bind up. It was an easy enough fix with a new shaft and related "o" rings. Towards the end of last season I had a PRV shaft bind in another unit. It will be an easy fix as well after I remove 6,000 lbs of 134a as the same basic engineering went into both devices as related to there shaft to housing design.
My question is are we seeing this happen as a result of poor internal lubrication? Oil is always at approx 120 degrees and 35psi by variable oil drive speed and seals lubed at 24 hr intervals per processor when standing by. Not sure tonight of exact hrs but units are 5 yrs old and maybe 30,000 hrs. Anybody else noticing similar problems? Any York upgrades know for fix? All feedback welcome, thanks

[york56]

When you say they were bound up with all linkage disconnected the arms don't move free on either prv or vgd they should be smooth.

[york56]

Could you provide a full M/N for the Chillers so I know what compressor we are discussing there is a SB on the J3 & J4 compressors for the PRV but I believe yours are newer style.

[aceairman]

Sure, Thanks. Model of compressor is YDHG - 73DD. The one of two units I mentioned had siezed the VGD shaft to the point of the actuator arm being bent before I found it. Upon removal and inspection it was bone dry and slightly filmed with a pattern of oxidation. The other 2500, has failed the MPB on OL when attention was directed to it. I found the PRV practicly siezed and very hard to move. I have noticed a black spot below the device forming on the evap barrel insulation from obviously some condesate drip and deteriorated seal material I am supposing. On this unit I see the residew below both compressors devices and conclude that they are all running dry as well. The units are not running below 42 degree setpoint and don't appear to have any noticable collected condesation on casing. I have proposed that all four shafts be pulled, reringed, lubricated and reinstalled and the one binding PRV shaft replaced but I see a pattern forming. Anybody seeing this?

[klove]

Provide the model # for the chillers. YDHG-73DD is for the compressor on the machine that you're on. Different size chillers will have different model compressors. May also help to provide a complete listing of serial #'s to see if they're sequential. I would assume that they are.

Could be that the same guy put all your vane/VGD shafts together and nobody told him to lube the collars. Oil temp, pressure, and frequency of lubrication don't have anything to do with the YK vane controls. Rust and acid in a machine will affect the operation. Any possibility that those problems exist? I know that's a long shot and not likely. I lean more toward incorrect assembly.

[aceairman]

klove, I'll check the sequential on serials Monday. The units with the problems I described are in two different plants and starts performed several years apart. We send oil samples off every year and no problems with oil have been reported. Do you know if York specifies a life span for the K-Oil (in the machine) that York recommends? I read its recommended to be disposed of if on the shelf even in its factory seal after two years. The oil is extremely admissible to moisture and I read moisture will migrate to a dry environment even if oposing positive pressure. Something to think about although my units are relatively brand new in respect to industrial equipment life.

[york56]

Do you know if York specifies a life span for the K-Oil (in the machine)

I have never seen anything to that nature. That is what oil samples are taken for , the report explains everything you need to know about the machine.

[aceairman]

Anybody getting involved in "o" ring leak problems on the yd's, I've had a couple units leak at mutiple connections at the oil resivoir. I had one 2500 a few weeks back blow a ring at the oil filter angle stop and we lost probably 30gallons of oil in an hour or so before it was noticed and secured. How about the oil heater? Anybody seeing failures in those? York has a new improved heater fix, anybody seeing discharge valve signal bounce? anybody having problems with those flow sensors............????

[york56]

Here are some of the SB that I have located for this Chilller.

[aceairman]

York56,
Thanks for the info. The facility and I are much appreciative! :patriot:Altimately you really know that you have paid a great service to all of us! If you ever get into town contact me and I will personally give you the tour. I'm sure with your degree of proffesionalism you will find it interesting.