Trane chiller problem

[dannycool]

Hi Guys

We have a pair of Trane RTAA chillers connect to a BMS panel with a Trend controller.
Whilst i was carrying out maintenance on the pump sets (auto changeover etc) the chillers locked out.
The chiller adaptive controller says it is turned off via an external source.
From what i can see there is Run/Fault indication and an enable signal between the chiller and the BMS, i think the enable signal is sent from the chiller and is interlocked with the pumps.
Since there is no fault indication on the panel and the pumps are operating and the pressure diff switches are ok, i was wondering if the chiller itself has a flow switch that needs resetting on the controller?

Any manuals on the controller operation would be appreciated aswell.

Thanks in advance

Danny

[Grizzly]

Danny.
It is just possible that you have a flow switch issue.
Check out if the attached are relevant?
Grizzly

Also I have tried to email you some info but your email address is throwing a wobbly!
Pm or email me and I will try again with the further info.

[dannycool]

Pm sent Grizzly

Just to let you know both chillers are doing the same.

Danny

[serviceman]

I understand that the units operate automatically RTAA (tracer, novar etc) pumps can be linked with the module I / O and hang time with the connection TB3-3, TB3-4, indicating unemployment is the external

[moideen]

Hi Guys

We have a pair of Trane RTAA chillers connect to a BMS panel with a Trend controller.
Whilst i was carrying out maintenance on the pump sets (auto changeover etc) the chillers locked out.
The chiller adaptive controller says it is turned off via an external source.
From what i can see there is Run/Fault indication and an enable signal between the chiller and the BMS, i think the enable signal is sent from the chiller and is interlocked with the pumps.
Since there is no fault indication on the panel and the pumps are operating and the pressure diff switches are ok, i was wondering if the chiller itself has a flow switch that needs resetting on the controller?

Any manuals on the controller operation would be appreciated aswell.

Thanks in advance

Danny

hi danny,as your chiller is in remote mode,so enable signal coming from remote(heare trend ccontroller) controller(not from adaptive controller).i think this fault due to the mis wiring of trend controller.
moideen

[The Saint75]

Danny, the chiller flow switches should be on dedicated terminals and not linked through the enable, which is from the BMS. Have you tried a reset on the BMS as that is your external source?

[dannycool]

Sorted the problem today after a good hour or so tracing wires through a panel which contains the controls for 4 boilers, 2 AHUs, 6 pump sets, 2 chilers, trend system and various other bits of kit and all relays and contactors were unmarked

Anyway it turned out that i was getting a 115vAC enable signal out of the chiller, through a trend relay, interlocked with the pumps, which were running,so far so good. The circuit was also interlocked with supply AHU which was held off by a belimo damper actuator that had come off its spindle and knocked itself into the closed position.
Remounted the offending actuator the system burst back into life!
I was wondering why they would employ the strategy of shutting down the chillers when the AHU is off, because there is also a fan coil circuit aswell?
Guessing its to do with running the chillers unloaded?

Regards
Danny