York YR WB WC T2-46 A Screw Chiller Motor Rotation Alarm
Today I went on a service call on a York YR Screw Chiller. The chiller had been running all last week just fine, but early this morning it went off on a motor rotation fault. I checked all of the voltages, phasing, and pressures. The manual said something about the discharge pressure needs to climb in the first 5 seconds of starting. The pressure transducers read spot on. When the compressor is trying to start the pressures do not change at all. It seems as if the compressor isn't really trying to start at all. No amperage is pulled on start up. When it goes into the starting/run mode I hear a click near the starter, and nothing happens.
This Chiller has a SCR type Solid State Starter on it. The information on the starter is as follows:
Part No. 371-02506-409
Another thing I noticed on the main chiller board was a CR18 light was lit red. It says fail above it. Does this mean anything?
If I will get more responses in the PRO Chiller forum please move it there.
Thanks for the help
Nothing related to your problem.
Originally Posted by Apprentice3
Sounds to me like you have a starter and/or interconnecting wiring problem between the control panel and the starter. Did you put a voltmeter on the output of the starter to see if you are getting voltages at start-up? My guess is that you would not.
No I am not getting any voltage out of the starter on start up. Is there some sort of manual for troubleshooting one of these starters?
Originally Posted by KnewYork
Yes, there is, but I'm inclined to believe you may not be getting a start signal from the control panel. Ask a moderator to move this thread to the Pro's Forum. Whenever a question is going to require technical and step-by-step procedures it needs to be done in the Pro's Forum.
If it is a motor rotation fault, not SSS fault, I believe it is due to the Head Pressure not increasing during startup. The micropanel thinks the motor is running backwards. We've had this happen at startup, with cold tower water coming back. Initially the condenser water sitting idle in the chiller is warmer in the mechanical room, then as the chiller starts colder tower water comes in and actually lowers the head pressure.This can be corrected with a tower bypass valve controlled by head pressure.
Again, make sure it is a motor rotation fault, not a SSS rotation fault.
Hope this helps
Mr. King has stated that he has no output voltage on T1, T2 or T3 at start initiation. Since the control panel has given a start command and there is no increase in discharge pressure in the first five seconds because the motor ISN'T turning the result is a motor rotation error message. IMO this has nothing at all to do with the compressor or cold condenser water or anything of the sort.
Mr. King might want to check to see if the starter is getting the start command from the Optiview control center. The control panel has given a command to run, so it thinks the starter is going to accept that command and fire the SCRs. If that happens the compressor will turn and discharge pressure will build. If the starter doesn't get the signal (check wiring and jumpers) there is no way for the control panel to know that, so it relies on other lack of inputs to tell it to shut down.