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Discussion starter · #21 ·
Buck,

I called you a while back to see how it was going on your end, left you a message. Hopefully it gets worked out. Mine took over a year!! Call or email me when you can.

Yorktek37,

I recovered 28 lbs of liquid out of the compressor! Total system charge is 76 lbs.My recovery machine was not happy with all that liquid, but I am glad I did that.

I started the compressor and was only able to run it for less that a minute, due to a defective suction line temperature sensor causing a Low Superheat reading. Actually reading - 9.1 F. The same is you unplug it. I found that the way the factory ran the harness on the suction line had a very stressful bend as it entered the sensor element. If I remove the sensor and let it hang straight, it reads, but if you move it it goes to -9.1F.

I believe the other circuit #1 will have the same problem soon, as it has in history the same erratic fault at time. I have ordered two sensors.

Once I get #2 online and the charge back into it, I'll have a chance to check the slide valve as Entropie suggested.
 
#22 ·
just did annuals on 2 machines day before yesterday and one machine had 2 out of 3 suction temp sensors bad. One was open and the other was shorted. HMMMMM You may be on to something there. Glad you pulled the liquid out. That could have been a bad deal. Recovery machine is much cheaper than a compressor. Does your unit have real txv's Or the half breed with the "heat motor"? I hate those damn heat motors. I see too many amatures out there that get the coil and the heat motor backwards when they jack with everything and before you know it the heater is burned out. I had 2 once that the factory hooked up wrong and lucily I caught it at startup. keep us posted.
 
Discussion starter · #23 ·
Boss

Boss,

Please move to Chiller Forum!

I have more to add! and ask!!

Please move to Chiller Forum!
Please move to Chiller Forum!
Please move to Chiller Forum!

Clicked my Steel Toed Boots many times!!!
 
Discussion starter · #24 ·
Stuck Slide Valve

I finally got back to this job.

Replaced the suction sensor on Compressor # 2 so I could run it.

Sure enough, runs "balls to the wall" fully loaded and will not unload, Entropie called that one!

Now, I have a few questions and observations.

1) Using the Amperage Method as stated in the service bulletin for the YCAS/YCWS Chillers, what is the lowest stage of unloading? The #1 Compressor will unload only to 64%. I can load up to 84%. Checking voltage at the I/O Expansion Board on J12 and J2 plugs, which controls the slide valve solenoid (which by the way I find it easier to unplug the signal and monitor the amperage rather than unplug the harness at the compressor as the service bulletin suggests) 0 volts will only unload the #1 compressor about 20% .I would expect up to 35% unloading.

2) When I allow the microprocessor run the #2 compressor as it sees fit, I lose the number #1 compressor on Low Superheat? within a few minutes.
#2 starts up and goes immediately into Suction Limiting.

Since the slide valve is not unloading this #2 compressor, this circuit will shut down and go through the AR time out cycle. Of course now the water temperature gets out of control due to both compressor are down.

I suspect low water flow through the barrel? Any thoughts?

Also, I do not know why the Microprocessor wants to run both compressors when the set point is within 2F and the #1 can easily hold setpoint as it has for over a month. Checking the signal to the capacity solenoids from the I/O Expansion Board, the microprocessor is telling both compressor to fully unload.

3) I will be changing the oil filters soon and taking oil samples along with installing new liquid driers.
Does oil pressure help control the slide valve on the DXS Compressor?

I will check and record torque when I remove the capacity control valve, but first I plan to check the Closed Thread Drain Port pressure to see what turns up.
Any other thoughts?
 
#25 · (Edited)
The solenoid valve on the compressor is a 3-way pressure regulating valve. It does control the oil pressure applied to the slide valve in accordance to the current running (voltage applied to the coil) through the coil. The voltage signal applied to the coil is related to the sv steps displayed in the micro panel. There are basically three roots which can cause slide valve stuck / move uncontrolled in high load position. 1. defective/overtightened three way valve. 2. lip seal leakage. The lip seals seal the compressor bearing chamber (under CDTP) from the discharge port. The three way valve does control as mentioned the outlet oil pressure and therefore reliefs some oil into the bearing chamber. Defective lip seals will increase the pressure in the bearing chamber and hence affect the pressure applied to the slilde valve. This can be determined by checking the pressure inside the bearing chamber (CDTP). If this pressure does not exceed the rated value, the lip seals are ok and the problem is probably the valve itself. Leaking lip seals can be bypassed with the available bypass kit. 3. Broken slide valve spring. The broken slide valve spring usually reveals itself by a high starting motor current. As soon as the compressor developes differential pressure (within the first rotor revolutions the slide valve is pushed in fully loaded position because the counter (unload) force of the spring doesn´t exist anymore. This can only be fixed by replacing the slide valve spring. Low water flow can be easily determined with the water temperature spread across the cooler. Typically the chiller should have something about 10 to 12°F with both compressors fully loaded under design conditions but should not exceed 18°F. Hope this helps.........
 
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Discussion starter · #26 ·
Very helpful

Entropie,

Thank you that information is very helpful. The lip seal explanation is a great help to me!

One the water flow issue, I was only getting a 6F spread because of the light load and the bypass loop was open, controlling 25 PSIG on the water loop.
45F Supply Water
51F Return Water

All 2 way valves at the Air Handlers.
All vav zones satisfied and Air handler frequency drives ramped way down due to static pressure control.
Metasys is not controlling the chiller. The chiller is operating on its local setpoint.

I still am puzzled by the Microboard calling for both compressors to operate during this low load condition. Outside ambient was 81F during that snapshot.

The lead lag is in auto and the #1 compressor was the lead according to the micro when it decided to start the #2 with Suction Limiting and causing the #1 to shut down on Low Superheat.

Is there a Eprom update I am unaware of?
 
#27 ·
It sounds to me that your YCAS has electronic expansion valves? Does the chiller has suction line HTX installed? What refrigerant R22 or R407C? Do you know the software version of the EPROM?
 
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Discussion starter · #28 ·
R22

R22 with electronic TXV's.

When I get back there I will check the Eprom Version, almost wrote it down when I was there yesterday, but got rushed off the roof and forgot.

I will go back later today on my way home.
 
#29 ·
Do you have the manual for the chiller? It is form 201.19-nm1. It is quite good, a lot of information about almost everything of the chiller.
 
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Discussion starter · #30 ·
Manual

The jobsite manual is Form 201.18-NM1 (102)

This is not the manual you suggested.

Just found on the manual, I have it on my truck, YCAS 2 System Eprom 031-01798-001.

FYI
The model and serial number and compressor is contained in my very first post on this machine, on page 1
 
#31 ·
The type of chiller you mentioned (YCAS0140EC17YGADBC) does indicate to me that it is a style G chiller. Form 201.18-nm1 does refer to style F chillers. They are basically quite the same but your manual probably miss the information / trouble shooting guide about the electronic expansion valves. But the section about the starting and stopping algorithm of the compressors should be equal. Take the time and read the manual, it is very good!
 
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Discussion starter · #32 ·
Eprom Version

Just arrived at the jobsite to obtain info.
Eprom Version C.ACS.09.09 21B8

You are correct on the jobsite manual, it is for the F version and this Job is the G version. No mention in the F version of the electronic TXV so I will need to get my hands on the correct manual.

Just noticed all history data is gone. Reads History Buffer is Empty?

Nice to have a air card in my laptop so I can scan the net and emails.
 
#33 ·
The software version is ok. There are no issues with the electronic expansion valve control. I suspect that the issue is when the compressor unloads to start the lag system. The degree of opening of the EEV might be to high. You should therefore check the position/proper reading of the suction line temperature sensor, superheat setpoint in the control (program key) and refrigerant charge / liquid subcooling. What is the suction superheat when the system is under part and full load? Is the refrigerant properly programmed (R22 not R407C)? Check your private message.
 
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Discussion starter · #34 ·
Info

It is programmed R22.
Superheat programmed 12F.
Replaced both suction sensors they where factory mounted at 8 oclock, so that is where I have kept them for now.
The subcooling I have not checked yet. Total system charge is 76 lbs. Sight glass is clear, but I know better to check subcooling. Will have to return Monday to check.
I read and replyed to the private message, Thanks!
 
Discussion starter · #36 ·
Compressor Replacement

Finally got the go ahead to pull and replace the #2 Compressor.

Found metal in the oil filter back on 9/2009. Oil analysis did not show excess, but suspected the compressor was started several times by in house full of liquid.

Anyhow, customer is not happy that York will not sell compressor parts.

Bitzer has a comparable compact screw compressor CSH-7561-80.

Parts are readily available for the Bitzer should future on site tear down is needed and any future rebuild is local and does not have to go back to York/JCI.

Plus price is half.

Customer wants us to install this and modify system piping to adapt.

Has anyone tried this on a YCAS140 machine? If so, are you satisfied with the performance?
 
#37 ·
dgruber said:
Finally got the go ahead to pull and replace the #2 Compressor.

Found metal in the oil filter back on 9/2009. Oil analysis did not show excess, but suspected the compressor was started several times by in house full of liquid.

Anyhow, customer is not happy that York will not sell compressor parts.

Bitzer has a comparable compact screw compressor CSH-7561-80.

Parts are readily available for the Bitzer should future on site tear down is needed and any future rebuild is local and does not have to go back to York/JCI.

Plus price is half.

Customer wants us to install this and modify system piping to adapt.

Has anyone tried this on a YCAS140 machine? If so, are you satisfied with the performance?
Click to expand...
Haven't had to yet, but it's been considered a time or two. Hanbell also has replacement comps that will go back in place. I'm sure there are some others, also. I didn't get far enough into it to decide how we would make the capacity control signal work from the York panel to the aftermarket compressor. What's your plan?
 
Discussion starter · #38 · (Edited)
Plan

klove,

The plan is still evolving.

I'll download some Bitzer information to see what signal options I have for the slide valve.

Thanks for the input on that issue.

If you want I'll be happy to upload the Bitzer info for your review on that issue, also.
 
Discussion starter · #40 ·
Oil

The York Type L oil would also need to be cleaned out.

The new Bitzer oil would then need to be added.

Need to find out if cross contamination of oils would be a issue.

If so, what would be the best way to clean and flush the oil system?
 
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