Trane RTAD125 Problems

[Latte]

Hi Guys,

I have spent the last two days in London looking at a Trane RTAD125 Water cooling system.
For those who dont know this unit, It has two independant systems going into one evaperator tank.
The customer believes that since it was installed in 2000 system/compressor two has never worked !!!!!!!

Now, The compressor has six points on it fed by two lots of three phase.
Contactor one pulls in and power the three points one side, the contactor has an aux on it which goes up to a 30ms timer and then should bring in another contactor to supply power to the 3 points the other side of the pot. Now the problem is that before the second contactor comes in the first one goes back out again.

I have changed over the aux's and the timers from system 1 to 2 but still the same.

No wiring diagram on site but i am assuming if there was a problem with the compressor it would blow the trips as opposed to releasing the contactor.

Has anyone had any experience of these units or any ideas.

Regards

Fatboy

[Temprite]

G'day Raymond.

try this.

www.usmotors.com/products/ProFacts/1-120-7.htm

[NoNickName]

Is it PWS start or Star/delta?

[NoNickName]

If it is pws, then the second contactor should kick-in after 500-1000ms from the first contactor and both shall stay engaged.
If it is star delta, there should be 3 contactors: star, center star, delta. The first is center star, and after few hundredths of a second, the star contactor should engage. Both shall disengage after 1-3 seconds, just few 1/100s before the delta contactor engages.

[al]

raymond

If like the yorks there is a current sensing module, then if this detects too high current or more likely no current then the first contactor will drop out, even before the second one pulls in.

there should be alarm history to support this, otherwise it could just be a bad output from the control board??

Alec

[arkay]

Hi Fatboy,

We are very happy with Trane chillers here. Most, if not all, Trane chillers I have come across have PWS start.
But I think your problem will be hard to solve without the wiring diagram. The customer has to seek it from Trane.

[Lowrider]

Have you solved the problem yet?

A RTAD uses a star/ delta. At 73% RLA it will switch over! If there is a problem you'll see it in the display. What kind of display do you have?

[Electrocoolman]

Sanderh.....Look at the date of the previous postings

[Latte]

Hi All,
Dont know what happened as i left the company that was doing the job. I think they were going to get trane in to do it.

Regards

Fatboy

[Lowrider]

I've seen the date, but never saw the solution! So I was just wandering!!!!!!!

[FreezerGeezer]

Solution: Get one of the Basingstoke lads to sort it.