York YK Oil Temp Problems

[CTI2010]

I have a York YK chiller, full model # is YKDPDSQ3-CKG. The problem I am currently experiencing is that the unit is generating a fault of High Oil Temp.

This fault is created when the oil temp reaches over 180. There is a brazed plate heat exchanger that controls the oil temp, fed liquid refrigerant directly from the condenser, through an expansion valve, and then into the evaporator through a ball valve. I watched it run for around 3 hours one day and I could see the oil temp climb slowly.

not much to the oil cooler, so I figured it had to be the expansion valve ( all of the refrigerant valves ARE open). I replaced the valve and monitored it for 2-3 hours. everything seemed okay.

Unit tripped the next day again.

Any ideas?

[KnewYork]

With machine running take accurate temperatures of the oil entering and leaving the oil cooler. Also take the temperature of the refrigerant return line to the evaporator. Post those here and maybe we can figure out what's going on. Are you maintaining a liquid level in the condenser? I think most of us would appreciate more information about yourself in your profile.

[CTI2010]

I have not monitored it since the last fault, but the oil temp leaving the cooler was around 6 degrees lower then the sump temperature from memory.... the exiting oil temp was 141-145 (going into the oil filter) and averaged 143.8 over a 50 min span (calculated from Fluke min/max setting). the sump temp at this point was around 149-150. in the 2-3 hours that I monitored the unit, the oil sump temp never went over 150. the unit was running balls out 100% FLA.

Oil pump was maintaining 37#, oil heater shows off... return solenoid shows open. Oil pump running at 45-47 Hz. Oil level in the "good" level of the sight glass, just about 50% mark. not low, not over filled.

I have been at this site since install. unit is around 3 years old. York performed factory start-up.

Annuals were due at the time of the call, so I started there to eliminate problems. New oil filter (canister evacuated), tubes brushed (no fouling).

[KnewYork]

If this machine is running at 100% FLA AND you are not maintaining a refrigerant level in the condenser I would suspect you aren't feeding enough refrigerant to the oil cooler. The refrigerant pick up is from the bottom of the liquid line if I remember correctly. If the VOV is wide open (i.e. no level in the condenser) you may have trouble feeding the oil cooler. There is no way (IMHO) you should ever see oil temperatures you are reporting in the sump.

Is your oil eductor working? The oil/refrigerant mixture returned from the evaporator also assists in oil cooling.

[nyrb]

On the oil side of the system you should have a 3 way AMOT valve that should be mixing hot and cool oil to maintain a feed temperature around 120 degrees. Take temp readings of entering oil to cooler, leaving oil from cooler and leaving oil from AMOT valve to ensure valve is functioning properly. Just something else to look at with that already mentioned.

[CTI2010]

I am not certain if it is. That was the next thing I was going to check on the unit. I noticed that this unit has a solenoid that appears to control the oil inductor and I was thinking that there could be a possible problem with the coil or control signal.

The condenser liquid level is just at the bottom of the sight glass on the condenser. This was also marked with a paint pen at start up with the charge weighed in (1,600 lbs) running at 100%.

I did not think to look at the oil return line because the unit was not having a problem with oil loss, it only occurred to me later.

there is an identical chiller next to this one that maintains 137 sump temp when running (it was a colder day and partial load). I was figuring perhaps 10 degrees higher might me normal since the unit was running 100% and warmer day since the oil heater is set to shut off at 160.

[CTI2010]

On the oil side of the system you should have a 3 way AMOT valve that should be mixing hot and cool oil to maintain a feed temperature around 120 degrees. Take temp readings of entering oil to cooler, leaving oil from cooler and leaving oil from AMOT valve to ensure valve is functioning properly. Just something else to look at with that already mentioned.

This was also something that I was told to examine after talking to a buddy of mine that was york factory.

I haven't had a lot of experience on the newer york chillers, epically the high pressure ones. (primary experience is with Carrier low & high pressure, Trane CVHE/F, and york low pressure. these are 2 of about 5 york high pressure machines I have worked on).

[york56]

If this machine is running at 100% FLA AND you are not maintaining a refrigerant level in the condenser I would suspect you aren't feeding enough refrigerant to the oil cooler. The refrigerant pick up is from the bottom of the liquid line if I remember correctly. If the VOV is wide open (i.e. no level in the condenser) you may have trouble feeding the oil cooler. There is no way (IMHO) you should ever see oil temperatures you are reporting in the sump.

Is your oil eductor working? The oil/refrigerant mixture returned from the evaporator also assists in oil cooling.

I would agree with statement I had one doing the same thing other guys had tryed to ajust txv but didn't help the problem , what I did do was calibrate the level probe after that the oil temp was more stable and lower. Before it would do exactly what you are discribing start out low and gradually climb once it hits its the trip threshold your done shutdown on high oil temp.

[KnewYork]

On the oil side of the system you should have a 3 way AMOT valve that should be mixing hot and cool oil to maintain a feed temperature around 120 degrees.

No 3-way (AMOT valve) on this design. Once the TXV was installed there was no need to bypass the oil cooler. All the oil passes through the cooler and depending upon the temperature of the oil, the TXV feeds refrigerant to the other side of the plate and frame heat exchanger.

The condenser liquid level is just at the bottom of the sight glass on the condenser. This was also marked with a paint pen at start up with the charge weighed in (1,600 lbs) running at 100%.

The level in the condenser when the chiller is running should be at about 1/2 the sight glass in the condenser. It is extremely important to keep the sub-cooler flooded. Run a trending screen on the liquid level at 5 second intervals and see what percentage is maintained. Let it trend for 20 minutes and see how steady the level is maintained. Before starting the trend see what the Optiview is reporting as the level. Depending on the skill level of the start up man there is a possibility the chiller was undercharged from the get go. (It wouldn't be the first time.) If you haven't worked on the level control or are unfamiliar with how it operates, I would suggest you read the service manual.

[CTI2010]

This makes sense, that is what I originally thought. I had traced out the piping and didn't see a bypass valve, but figured maybe I missed something.

I will check the level and set point when I return to the site.

Does anyone know the service log in codes off the top of their heads?

I know standard login is user id 0 and 9675

I have not used the service login in quite some time... I believe the last time i logged in under this setting I may have used the same used id of 0, and the code was something like 3785?

[KnewYork]

You really need to get a service manual for the Optiview panel. If you don't know the service password, how could you possibly be able to troubleshoot and properly adjust the level controller? You don't need a service password to set up a trending screen. Setting up a trending screen is covered in the IOM manual.

[nyrb]

Once the TXV was installed there was no need to bypass the oil cooler. All the oil passes through the cooler and depending upon the temperature of the oil, the TXV feeds refrigerant to the other side of the plate and frame heat exchanger.

Thanks for the update, haven't seen any with that configuration yet.

[CTI2010]

Turns out the problem was that the metering valve actuator was actually going out. New actuator is on order.