trane rtac wont respond to start command

[gojira]

I have a tRANE RTAC2504 air cooled chiller that will not start when given a start command. The flow switch is closed the return water is 56f and the setpoint is 44. I have 22 volts dc @ the circuit but the chiller just stays in start inhibit with no response. I used to have a friend @ trane but he moved on and trane will not give me any help ot tech assistance

[deltap10]

Maybe Tracer is holding it off. Try local mode. If you are using Techview you should be able to see the problem.

[R123]

Your start/stop relay probably isn't made.

[Trane_Dude]

First, make sure the chiller is in LOCAL control and then jump out the SS on the card, then see what happens.

[cperk]

First, make sure the chiller is in LOCAL control and then jump out the SS on the card, then see what happens.

If the chiller is in local and you hit auto, it does'nt care if the remote ss contacts are made,or not, does it? Hit local in setpoints, and if it still does not run, and says start inhibited it should tell you why when you touch the start inhibited line. I.E. start inhibited by low saturated cond. temp. Just a guess. What is the ambient temp.? Does it have low ambient capability?

[Trane_Dude]

If the chiller is in BAS control and is not occupied by BAS it will not start even if the SS is closed. That's why I say put the machine in LOCAL control and close the SS. If it still says inhibited by and external source then there is something wrong with the SS input.

If it just says inhibited then there is something else going on. It should say inhibited by an external source.

[R123]

If the chiller is in local and you hit auto, it does'nt care if the remote ss contacts are made,or not, does it? Hit local in setpoints, and if it still does not run, and says start inhibited it should tell you why when you touch the start inhibited line. I.E. start inhibited by low saturated cond. temp. Just a guess. What is the ambient temp.? Does it have low ambient capability?

The SS contacts still have to be made when the chiller is in local. The local/remote setting is only for BAS control.

[kmay2691]

Check the 115 Volt control circuit. There is a fuse in with the condenser fan fuses, it is a 10 amp fuse. If it is bad look for bad solenoids on the compressors or any thing in the 115 volt circuit.

[R123]

Check the 115 Volt control circuit. There is a fuse in with the condenser fan fuses, it is a 10 amp fuse. If it is bad look for bad solenoids on the compressors or any thing in the 115 volt circuit.

If that fuse was bad, you wouldn't have any control power and the display would be blank.

[kmay2691]

If that fuse was bad, you wouldn't have any control power and the display would be blank.

Nope, dyna view is powered thru 24 volts and will be on, trust me I have fixed this numerous times.

[R123]

Nope, dyna view is powered thru 24 volts and will be on, trust me I have fixed this numerous times.

Your right, DynaView is powered by 24 volt circuit. I had my fuses confused....but how would the 115 volt volt fuse being blown cause a start inhibit since the SS LLID is a dry contact and all the LLID's are 24vdc.

[kmay2691]

Your right, DynaView is powered by 24 volt circuit. I had my fuses confused....but how would the 115 volt volt fuse being blown cause a start inhibit since the SS LLID is a dry contact and all the LLID's are 24vdc.

Flow Switch is an optical input powered thru the 115 volt circuit, No flow switch no chiller start.

[gojira]

sorry guys i have been in south carolina and ga on service calls and do not have acomputer in my truck. Turns out that the unitonly had 20 psi of 134 and the transducer read this as 21 degrees of ambient temp. Unplugged 1st stage transducer and second stage came right up.Thanks for all the help