CVHE500 Trane Centrifugal

[randystoker]

I have a trane chiller model # CVHE500 that has a problem with surging after initial startup. When I switch over to this chiller, as soon as the vanes start opening the chiller starts surging very loudly. I look at the head pressure and it is at -0.1 psig. I assumed if there was air in the condenser it would be reflected in high head pressure while the machine is surging which is not the case. Also, when this machine is started, the chilled water is already down to 50F due to a redundant chiller that was already running, so not a big load on the machine. Also, the condenser water does not have a chance to pick up any heat before the machine starts surging severly, it is still around the pre-start temperature of 79F. I did notice multiple excessive purge warnings in the history alarms of the chiller. Could it have so much air in the system that the machine cannot load up to register the high condenser pressure?

[Healey Nut]

Sounds like shes full of air , leave the chiller idle put the purge on and compare the actual refrigerant pressure of the chiller to a PT chart and see how close you are .
You need to post a lot more info on the chiller if you want more help ,,,,, serial # what kind of control system etc
This really should be posted in the chiller section too

[jpsmith1cm]

Moved to Open Chiller forum

[jayguy]

I have a trane chiller model # CVHE500 that has a problem with surging after initial startup. When I switch over to this chiller, as soon as the vanes start opening the chiller starts surging very loudly. I look at the head pressure and it is at -0.1 psig. I assumed if there was air in the condenser it would be reflected in high head pressure while the machine is surging which is not the case. Also, when this machine is started, the chilled water is already down to 50F due to a redundant chiller that was already running, so not a big load on the machine. Also, the condenser water does not have a chance to pick up any heat before the machine starts surging severly, it is still around the pre-start temperature of 79F. I did notice multiple excessive purge warnings in the history alarms of the chiller. Could it have so much air in the system that the machine cannot load up to register the high condenser pressure?

with R123 and 79F condenser water, you would have about 1.8" Hg vacuum which is about what you already have. i suspect that the condenser pressure that you are reading is a condenser TEMPERATURE converted to pressure rather than a real condenser pressure...put your gages on it and read the real pressure.

never trust the display until you have verified the sensors first, then feel free to use the displayed readings for further troubleshooting.

[Healey Nut]

with R123 and 79F condenser water, you would have about 1.8" Hg vacuum which is about what you already have. i suspect that the condenser pressure that you are reading is a condenser TEMPERATURE converted to pressure rather than a real condenser pressure...put your gages on it and read the real pressure.

never trust the display until you have verified the sensors first, then feel free to use the displayed readings for further troubleshooting.

If hes got 50 degree water running through it with the chiller off he should be way lower than 1.8" with the chiller idle if theres no air in it .
Even if its on R11 he should still be lower he doesnt say its a R123 chiller ??
So were P%#$@&g in the wind really

[jayguy]

If hes got 50 degree water running through it with the chiller off he should be way lower than 1.8" with the chiller idle if theres no air in it .
Even if its on R11 he should still be lower he doesnt say its a R123 chiller ??
So were P%#$@&g in the wind really

true. although he didn't specifically state it, i took his description to mean that the chiller was started...

I have a trane chiller model # CVHE500 that has a problem with surging after initial startup. When I switch over to this chiller, as soon as the vanes start opening the chiller starts surging very loudly. I look at the head pressure and it is at -0.1 psig....

[deltap10]

I had one that acted like that once. Blown rupture disc.

[trama]

if this has the trane electronic control of any version then it is possible that the cond pressure displayed is cond temp converted to pressure, the evap pressure is a temperature conversion as well, even with the chiller off both will read a pressure close to temperature relationship if there is air or not, please post more info, machine serial number(first 4 digits is enough it will be Lxxx) and the style of control panel would be helpfull ucp II/ch530 etc

[randystoker]

Here is the additional info. requested, had a time getting back to this after other high-priority jobs. The Trane chiller serial # is L09A05923, refrigerant 123, Tracer adaptiview display/software & date of manufacture of the chiller is 22 Jan 2009. After startup, as soon as the vanes start opening, the machine starts surging. One of my co-workers had a laptop hooked up, closed the vanes back down, surging stopped. As soon as he started to open the vanes slightly, the surging started again. It got worse as the vanes opened more and he closed them back down. Purge unit has repetitive alarms for excessive pump-out time. Condenser pressure shown on the adaptiview screen is not high when it starts surging.

[jayguy]

...Purge unit has repetitive alarms for excessive pump-out time...

key sentence.

without ACTUAL numbers (pressures/temperatures/etc), it is difficult to tell what is going on for sure, but it sure sounds full of air to me.

[milkyway]

sounds like time to leak check.,

check economizer ., suction,. tang , purge location., may be able to just give it a good tighting., rupture disk as stated.

[ZeroTolerance]

Does your purge system run excessively or more than normal? Sounds to me like you have a leak as well. Time to hook your hot water heater up to it :P

We have a leak on our 175ton pony Chiller and the purge runs 24/7. We are waiting till it blows up haha

[Tech Rob]

Don't get out the water heater just yet! First thing you have to do is check out the purge. Could be a very small, very cheap part that's got you all messed up and ready to spend thousands of dollars of this customer's money.