RTAA140 Trane unit running crazy!!!

[fool4school]

I have a RTAA air cooled trane chiller that has 2 circuts on it. I have had problems with circut #1 going in to a alarm that is 1B7 that is a compressor overload alarm then it will have a code for low oil flow, then it will have a alarm on the condenser pressure being high and then a loss of comunication, then a alram on the evap. pressure being low. I fixed to leaks on this circut, Turned the power back on. Let oil warm for 45-60 MIN. turn the switch back to atuomatic mode, then before the compresser even started, it was locked out on compresser overload again!!! Starting to wonder if the microprosser board might be going bad. My coil is clean all condenser fans are coming on when it runs. THis makes the other circut run @ a overloaded state to up to 120% then it will shut down..
Has anybody seen these symptoms ?? Is the board flaking out ??? I checked all the conections with the little plastic tool trane gives you and reconcted all the plugs and jacks as well. THere is 5 microprosser boards on this unit and they all have to "talk" to each other.
And lets not talk about the "ice Mode" !!!

[jayguy]

...And lets not talk about the "ice Mode" !!!

are you running this unit in ice making mode?

and yes, all of the boards need to talk to each other.

[fool4school]

Yes, it dose have a ICE mode. When both circuts are working it will make about 60-70% of ice. I have it running 9 hours in ice mode. But, if one circut shuts done you can forget about making any ice to any kind of level it burns off fast in the daytime.. Im sure this was a good system 12-15 years ago but it has become very cumbersome and very erratic in its old age.

[Healey Nut]

Im sure this was a good system 12-15 years ago but it has become very cumbersome and very erratic in its old age.[/QUOTE]


This is what happens to poorly maintained/serviced equipment . Particularly when the work is performed by techs who are not knowledgeable about this particular piece of equipment .
The RTAA is the small and larger tonnage version is a great chiller . I look after several of them and some of them are 98 vintage . Still humming along quite happily . Have they had problems ....of course there mechanical pieces of equipment . I wouldnt have a job if stuff didnt need service .
Good proper service by knowledgeable techs goes a long way to equipment reliability and longevity .

[darooo]

Do you have IOM manual?

[milkyway]

I have a RTAA air cooled trane chiller that has 2 circuts on it. I have had problems with circut #1 going in to a alarm that is 1B7 that is a compressor overload alarm then it will have a code for low oil flow, then it will have a alarm on the condenser pressure being high and then a loss of comunication, then a alram on the evap. pressure being low. I fixed to leaks on this circut, Turned the power back on. Let oil warm for 45-60 MIN. turn the switch back to atuomatic mode, then before the compresser even started, it was locked out on compresser overload again!!! Starting to wonder if the microprosser board might be going bad. My coil is clean all condenser fans are coming on when it runs. THis makes the other circut run @ a overloaded state to up to 120% then it will shut down..
Has anybody seen these symptoms ?? Is the board flaking out ??? I checked all the conections with the little plastic tool trane gives you and reconcted all the plugs and jacks as well. THere is 5 microprosser boards on this unit and they all have to "talk" to each other.
And lets not talk about the "ice Mode" !!!

i am not a pro!
i would start with the ipc wiring,(connections) also , the differantial pressure , if not correct , will cause problems, then check ur oil circuit, then u say condenser pressure, why is the machine not rejecting the heat, ? did u perform test on txv?

[milkyway]

high condenser pressure will cause loss of oil flow alarm., due to the higher pressure the oil moves faster and throws this alarm,

[HJ Controls]

oil flow is caused by oil filter, worn rings on check valve, high condensing pressure also if your saturated condenser or oil thermistors are not reading correctly.
temp drop across oil cooler should be around 20 degrees and oil drop across filter, check and solenoid should be around 10 psi
but the first thing you going to have to do is clean condenser coils or replace fans to get head down.

good luck