York Chillers Surging

[DesAngler]

I have 3 York Centrifugal water-cooled chillers... 2 running and 1 stand-by.

Chiller 1 keeps surging, raising from 60% to peak load of 90% and then unload again back to 60% within 1 minute. The process keeps going this way...

Hope some kind folks can advise me the reasons....

[mustardman]

I am not being rude but if you are questioning why a chiller surges you should call a qualified contractor to come look at it. What I will say is current limit chiller number 1 at a point where it won't surge or better yet turn it off and start a different machine if possible.

[DesAngler]

I am not being rude but if you are questioning why a chiller surges you should call a qualified contractor to come look at it. What I will say is current limit chiller number 1 at a point where it won't surge or better yet turn it off and start a different machine if possible.

Thanks for your reply... but I thought this forum is a place for discussion and a place for everyone to learn about HVAC systems?

3 chillers, 2 on, 1 standby, all chillers take turn to operate every week. If don't find out the reasons of surging and keep it off while the other 2 on, it serves no purpose in having the 3rd chiller as stand-by unit then... agree?

There may be many reasons why a chiller surge under different conditions. Just an open topic for discussion on the possibilities of surging. If call contractor, everyone won't see a need for this discussion forum.

[local 832s]

Air in system. Hows the purge working? Low pressure? Refrigerant?

[referteacher]

I'd love to get into this discussion but don't have the time right now.

What your describing doesn't sound like a true "surge" situation. Surging is more "harsh" than what you're describing. It sounds to me like you have a "hunting" situation where the chiller loads and unloads over a period of opne minute.

To see a good long discussion of what surge symptoms and causes are, try going to the "search" link above and type in "harsh Trane chiller". There have been several discussions on the subject of surging but that one I was involved in so I remember it. There are others. You might try browsing through them.

Good Luck

[TAC Service]

First, you need to determine if your machine is surging or the control system is hunting. There are two (2) types of surges, a high side surge which sounds like an elephant yelling, this is when refrigerant is moving backwards thru the compressor from the high side to the low side. The compression ratio has exceeded the lift of the compressor, and for that short moment the wheel does not move anything and you have a sudden drop in motor amperage. This is caused by dirty condenser, low condenser water flow, non-condensibles, etc.

A low side surge has a low grumbling noise, this is when the compressor is starving for refrigerant. The compresor runs out of refrigerant to pump and that causes your momentary drop in motor amperage. This is caused by a low refrigerant charge, dirty evaporator, low load conditions, etc.

If the vanes are not backing off when the machine unloads it is probably a surge. If the vanes are opening and closing you need to look at the temperature control system or the load limiter.

[jsherhvac]

Is the machine within design parameters? Take a log on the machine something should stand out, it could be something in the controls but not likely. If all else fails call a professional chiller company.

[Pneuma]

I have 3 York Centrifugal water-cooled chillers... 2 running and 1 stand-by.

Chiller 1 keeps surging, raising from 60% to peak load of 90% and then unload again back to 60% within 1 minute. The process keeps going this way...

Hope some kind folks can advise me the reasons....

What is your condenser water inlet and outlet temperature? You need to see what that split is, in general terms a very wide split means you are not getting good water flow, very narrow means you have dirty tubes. You could also have air in the machine, is the purge working?

BTW chiller surges are pretty common and they sound worse than they are. Your machine will not die as long as you get this fixed soon. Like everyone said, call a proffesional unless you are very confident with such things as isolating this chiller, draining the condenser and pulling the head. You can definately rod the tubes, but you'll wish you had called a pro after about 15 minutes of it!

[pecmsg]

We need a Lot More Information Post your readings. There are just too many things that can cause surging to even guess with out #’s.

[season0174]

We need a Lot More Information Post your readings. There are just too many things that can cause surging to even guess with out #’s.

Agree.... totally, absolutely, utterly...
there are just too many reasons caused the chiller surging.

System got air in
Condenser Condition
Cooler Condition
Water Temp.
System charge
VSD's Function
Vari. Orifice.... too
.......
...
..
.

[Shophound]

A surging chiller is quite audible. If you're seeing the 60% to 90% variance in chiller load without the characteristic shriek, growl, or grumble, it would lean me toward a guide vane/prerotation vane/capacity control issue.

You definitely need to log the machine if you're not already doing it. If you're in this plant daily, daily logging might seem like a chore, but it comes in handy when things get off course.

[snipe70e]

A surging chiller is quite audible. If you're seeing the 60% to 90% variance in chiller load without the characteristic shriek, growl, or grumble, it would lean me toward a guide vane/prerotation vane/capacity control issue.

You definitely need to log the machine if you're not already doing it. If you're in this plant daily, daily logging might seem like a chore, but it comes in handy when things get off course.

Logs are the only way. the previous owners' crew of the building I am at never did any rounds or logs. With in one month of my starting to take and record readings the chiller started to surge badly. by looking at the log sheets we could see when it developed a leak. found loose tubing fitting tightened and started to work air out. with log sheets we could tell that we had gotten the leak. If my boss or the property managers doubted the time it took ,me to do rounds, they became convinced. I only get to get one complete set of readings a day wish I could do it more often.

[chiller mekanik]

First rule when asking a question about any chiller, know which one your asking about. And for the record, "water cooled York centrifugal" does not get it. In fact, if the post doesn't contain the first few letters of a model number, most of us know right away that the post is from someone that doesn't service large tonnage chillers. And here is another clue, if you post the first 2 to 6 numbers/letters we already know which brand it is.

Also, always be ready to post a log. General questions are fine if they truly are general. For example: I may want to start a discussion about low condenser water temperatures, pros & cons. But if I'm trying to figure out why my green water cooled centrifugal is not working right, I need to post a question concerning my oil loss trouble on my 19DK.

Now, when I post 19DK, all of those that can help me know that it is low pressure, made by Carrier, most likely has R-11 in it, they understand my oil system completely & they also know how cold my condenser water can get & when it can effect my oil return, if it can effect my oil return & how to tell the difference.

I realize I could have used an example with a surging water cooled York, but my intent was to demonstrate the complexity of chillers in general.

Good luck! Oh yeah, and please post a log.

[stickerhead]

I have 3 York Centrifugal water-cooled chillers... 2 running and 1 stand-by.

Chiller 1 keeps surging, raising from 60% to peak load of 90% and then unload again back to 60% within 1 minute. The process keeps going this way...

Hope some kind folks can advise me the reasons....

Might not be air at all. You failed to say what kind of York (OT,HT,YT,YK) and what control panel it has. Could be in the elctronics

[bigbilly]

I had one several years ago that had similar probs. Cooling tower water was to high.

[baddirty1686]

I hope I am doing this right. I need to know if there is a place in the Tennessee Georgia area that can go through and re-build a compressor on a 19 dk machine?

[Chiller Guy]

You cannot fix a unit unless you know what is wrong with it. You cannot tell what is wrong if you do not log the unit and analyze the data. Post a M# and some operating data and you will get lots of help. Do not think that "surge" is only a noisy condition as will wipe out a machine (bearings,seals) if not corrected. Expensive machines can have expensive problems.

[york56]

I have a question are the machines depending on age and type more like the newer style in local or remote because if they have noncondensibles in them in remote they will want to go to 100% load limit then surge and back off in remote you can't control the load limit but in local you can set the load limit and back off on the chiller to see if it stops. I also agree with logs they help with trouble shooting issues. JMHO

[MrYork]

York56, I like your cat...or is that you in that pic. Haha

[york56]

No thats not me but that how I feel when Im stressed out on the job.