I have been working on a cvhf490 today and am a little baffled.
It was shutting down and restarting every 1/2 hour or so with no diagnostics.
I logged it out at various times and observed the following abnormalities.
set point is 42
fluid is water
#1 LCW sensor appeared to be off 7 degrees .
It appeared to have high approach and the sat suc was falling below 34 with a leaving water of 48 .
After measuring the actual LCW a foot down stream of the sensor I actually had a leaving water of 37.
I changed the sensor and restarted the chiller and had the same problem , sensor appeared off and approach was high .
measured the voltage at the power supply and sensor , 24 VDC , all other sensors OK.
#2 I have always complained to the BLDG owner about the current ,
at one point I read 213A , 257A , and 314A from the CH530 as well as the display on the starter .
I also caught it in phase imbalance limiting mode a couple of times .
#3 the condenser side looks good, 79 water in , 89 out, 0.5 approach
# 4 after the sun went down it all started acting better and stayed online but still surged at times ( mildly)
the LCW sensor started reading properly
the current is still off but not as bad .
The evap approach is still a little high compared to previous logs , now 4.5 but was 0.9 this morning
ECW 53 , LC2 42,
I am starting to feel it was shutting down on phase imbalance as I raised the setpoint to keep the sat suc above 37.
Why don't I get any kind of message as to why it shut down every 1/2 hour for 5 + hours,
#1 I never made setpoint or diff to stop
#2 I never witnessed a sat suc lower than 36 ( after raising SP early on )
#3 approach always appeared to be in excess of 10 at shutdown
#4 witnessed it in current limit a few times and phase imbalance but never caught it in these modes at shut down.
#5 IGV was always above 60% when it shutdown , it would rapidly unload then stop.
I am baffled