Trane CVHG problem

[bunglebear]

I have got a problem with a CVHG three stage centrifugal machine. On arrival this morning the machine was in fault, showing a phase loss fault, so checked it out. The start contactor pulls in for a second or so, drops out, pulls in again and drops out. The run or shorting contactors don't even pull in at all. I checked the mechanical interlock and that was OK, the CT's I decided to check, but thought I'd better look at the binding view first. I had 27 red faces. Nothing is bound. I tried to bind the components but nothing will bind. I can turn the LED's all on with a magnet, but when I try to bind the LED just goes out. I have the option on Techview to turn on and off all LED's, but it won't turn them on, so I had to use a magnet. For the individual components, the LED on and off options down the side is grayed out and not selectable, At first I thought it might have been the COM4 board, but now I think the controller may be faulty. I even unplugged the controller, plugged it back in and there's Comms Loss Motor Temperature 1, 2 and 3 faults which won't clear. IN addition there's a VCI Emmitter inside the control cabinet door, which has split (Although I don't actually think that's a factory fitted item)

Has anyone else had a problem like this one???

Thanks

[ChillerWisperer]

I have got a problem with a CVHG three stage centrifugal machine. On arrival this morning the machine was in fault, showing a phase loss fault, so checked it out. The start contactor pulls in for a second or so, drops out, pulls in again and drops out. The run or shorting contactors don't even pull in at all. I checked the mechanical interlock and that was OK, the CT's I decided to check, but thought I'd better look at the binding view first. I had 27 red faces. Nothing is bound. I tried to bind the components but nothing will bind. I can turn the LED's all on with a magnet, but when I try to bind the LED just goes out. I have the option on Techview to turn on and off all LED's, but it won't turn them on, so I had to use a magnet. For the individual components, the LED on and off options down the side is grayed out and not selectable, At first I thought it might have been the COM4 board, but now I think the controller may be faulty. I even unplugged the controller, plugged it back in and there's Comms Loss Motor Temperature 1, 2 and 3 faults which won't clear. IN addition there's a VCI Emmitter inside the control cabinet door, which has split (Although I don't actually think that's a factory fitted item)

Has anyone else had a problem like this one???

Thanks

What vintage is it? Does it have ribbon cable and butterfly connectors or the newer Delphi connectors? Have you tried to bind any of your panel LLIDs? I've run into similar issues with ribbon cable machines and tracked it down to shorting in the comm bus somewhere in the cable and replaced the bad section. I also had a Delphi connector RTAC I was starting that had a shorted EXV motor that would'nt let anything bind until I disconnected the EXV. Start disconnecting LLIDs one by one and try to rebind something after each one. When you have a successful bind, the last component you eliminated probably has a defective LLID.

[bunglebear]

It has to be around 3-4 years old and has the ribbon cable with the white push on connectors. Maybe I'll try doing that tomorrow and see where it goes. I think I used to have a manual with some sort of check out procedure for this, so I'l have to start going through all my old files as well.

[Healey Nut]

Like CW said you need to start dissconnecting components in sequence or break the daisy chain into several small chains and eliminate components . It sounds like you have either a shorted or grounded component or a section of the ribbon cable is grounded or shorted . Look for areas of the cable where it is tie wrapped or tight against something else . Or where the cable is doubled back on itself check its not cracked particularly at the oil transducers .
Take your time and be methodical and you will find it ,its just a process of elimination .
Good luck.
The VCI emmiter, is it a round yellow sponge thing about 3or 4"s in diameter ?? Is this chiller in a corrosive environment ,paper mill etc ???? Thats where they are usually used in the panels (VCI emmiter)
If it is this maybe your problem ???? (Corrosion)

[goshen]

I have got a problem with a CVHG three stage centrifugal machine. On arrival this morning the machine was in fault, showing a phase loss fault, so checked it out. The start contactor pulls in for a second or so, drops out, pulls in again and drops out. The run or shorting contactors don't even pull in at all. I checked the mechanical interlock and that was OK, the CT's I decided to check, but thought I'd better look at the binding view first. I had 27 red faces. Nothing is bound. I tried to bind the components but nothing will bind. I can turn the LED's all on with a magnet, but when I try to bind the LED just goes out. I have the option on Techview to turn on and off all LED's, but it won't turn them on, so I had to use a magnet. For the individual components, the LED on and off options down the side is grayed out and not selectable, At first I thought it might have been the COM4 board, but now I think the controller may be faulty. I even unplugged the controller, plugged it back in and there's Comms Loss Motor Temperature 1, 2 and 3 faults which won't clear. IN addition there's a VCI Emmitter inside the control cabinet door, which has split (Although I don't actually think that's a factory fitted item)

Has anyone else had a problem like this one???

Thanks

Hi had the same problem turned out to be a shorted ribbon on condenser sensor a royal pita!!!:eek2:

[bunglebear]

In the end it turned out to be the ribbon cable so that's at leasst fixed. On starting the machine it was throwing a phase loss fault up as well. Anyway, checked the CT's and they all checked out at 128 ohms. I did a diode check as well on the inputs to the starter module and got 0.02volts. I had a check out guide to a wye delta starter for a RTHD which gives a guide of 1 to 1.5volts. This leads me to think that maybe the starter module has a defective current input. The start relay/contactor pulls in for about a second and drops out (no star contactor oulling in) It does this twice then brings up the fault. I think I am going to order a new starter card and go from there.

Thanks for all the replies..

[goshen]

In the end it turned out to be the ribbon cable so that's at leasst fixed. On starting the machine it was throwing a phase loss fault up as well. Anyway, checked the CT's and they all checked out at 128 ohms. I did a diode check as well on the inputs to the starter module and got 0.02volts. I had a check out guide to a wye delta starter for a RTHD which gives a guide of 1 to 1.5volts. This leads me to think that maybe the starter module has a defective current input. The start relay/contactor pulls in for about a second and drops out (no star contactor oulling in) It does this twice then brings up the fault. I think I am going to order a new starter card and go from there.

Thanks for all the replies..

hi u could also try to disable via techview phase protection this will tell u if u have a problem with the ct.

[jayguy]

hi u could also try to disable via techview phase protection this will tell u if u have a problem with the ct.


this is also a fantastic way to make sure your chiller gets replaced

(don't do this)

[goshen]

this is also a fantastic way to make sure your chiller gets replaced

(don't do this)

Hi when trying to solve a problem and all else checks out,using external tools, nothing will happen when disableing this protection once!!!
if u ever need to replace the star delta starter with a soft starter u will have to disable this protection,
Were dealing with professionals here that should know what they are dealing with!!!

[jayguy]

...Were dealing with professionals here that should know what they are dealing with!!!

really?

i think that you need to read more posts around here.

[goshen]

really?

i think that you need to read more posts around here.

Point taken !!!!!!