Trane chiller RTAC250

[cool king2007]

Hello everyone,

i have problem with my Trane chiller RTAC250 that is low evaporator Rfgt Temp - ct1
and sometimes the same compressor tripped by low suction Rfgt pressure - ct1.so what shall i do?
Thanks

[chillerman2006]

Hi Cool King

Ask an engineer to sort out the problem

R's chillerman

[goshen]

Hi
you should takeCM 's advice!
this problem is something a tech that is qualified will be able yo deal with .
good luck

[cool king2007]

good evening,

these massages appaer as alarm so i think the unit needs more gas, is that right?

thanks

[chillerman2006]

good evening,

these massages appaer as alarm so i think the unit needs more gas, is that right?

thanks

Evening Cool King

this does not have to be a refrigerant charge issue

it could quite as easily be a problem with part of the system

unless you can provide a full list of operating conditions

temperatures/pressures at various points

water temperature in/out confirm flow, correct vessel resistance

Its hard to give you an answer and really needs an engineer to attend to diagnose

R's chillerman

[Sumit]

Hello ,

As per my experience , i have seen that mostly " low evaporator pressure " is due to low level of refrigerant in the chiller.In addition , there may be some problem in expansion valve.

Cool king , please provide us various parameters as chillerman said.

Have a good weekend.

[Grizzly]

I can think of at least 6 or 7 other things that will or could give the same fault.
In fact I have had to remove refrigerant charge from chillers maintained by very experianced engineers,who made the same assumption.
The advise being given is cautious for a reason, without the correct facts damage could occur.


Grizzly

[chillerman2006]

I can think of at least 6 or 7 other things that will or could give the same fault.
In fact I have had to remove refrigerant charge from chillers maintained by very experianced engineers,who made the same assumption.
The advise being given is cautious for a reason, without the correct facts damage could occur.


Grizzly

Hi Grizzly
You had them too mate,
last one stuck flow switch, pumps not running(turned off der!)
and had to drag out over 22kg that had been dumped in
its quite amazing sometimes how dangerous a little bit of knowledge can be
& why do companies allow some to work on our kit...beats me
well with f-gas quals being so hard..things should improve
R's chillerman

[Grizzly]

Thanks for the input chillerman.
Yep assuming can be humbling!
I prefer to say nowadays, "With what I know so far it would be a good starting point."
We all do it!
Chillers as you know have lots of reasons for displaying Low Suction or Temps.
Many times only because it's the first Fault parameter listed.

I hope coolking has not taken offence and keeps us all informed.
It would be interesting as what the actual cause of the alarms is.
Grizzly

[chillerman2006]

Thanks for the input chillerman.
Yep assuming can be humbling!
I prefer to say nowadays, "With what I know so far it would be a good starting point."
We all do it!
Chillers as you know have lots of reasons for displaying Low Suction or Temps.
Many times only because it's the first Fault parameter listed.

I hope coolking has not taken offence and keeps us all informed.
It would be interesting as what the actual cause of the alarms is.
Grizzly

Yeah me too mate
I was referring to ones who worked on kit prior to me

If he can start to list the conditions it wont take long to confirm whats going on
Just did not want him chucking in refrigerant if not needed

CoolKing we still here for you if we can help mate

R's chillerman

[cool king2007]

Hello everyone,

Operation conditions for TRANE chiller RTAC250 at different times:
at 8:00 am (SEP 27,2011)
Modes
chiller mode: Running
circuit 1 mode: Auto
cprsr1A mode: Auto
cprsr1B mode: stopped
circuit2 mode: Running
cprsr2A mode: Running
Chiller
Evap leaving water Temp: -7.2c
Evap Entering water Temp: -5.7c
Active chilled water setpoint:-7
outdoor air temp: 26.9c
compressor
1A
Amps L1 L2 L3 : 0.0 0.0 0.0
%RLA L1 L2 L3 : 0.0 0.0 0.0
unit volts : 418
oil Temp: 28.1c
Intermediate oil pressure: 127kpag
suction pressure: 124kpag
1B
Stopped Because comm. Loss: Starter 1B
2A
Amps L1 L2 L3: 120.0 115.0 113.0
% RLA L1 L2 L3: 62.6 58.5 55.5
Oil Temp: 58.9c
Intermediate oil pressure: 803kpag
Suction pressure: 104kpag
Rfgt ckt1 ckt2
Cond Rfgt pressure: 614 939 kpag
Sat cond Rfgt Temp: 27.3 41.0 C
Evap Rfgt pressure: 125 104 kpag
Sat Evap Rfgt Temp: -6.9 -9.4 C
Evap Approach Temp: …… 2.7 C
Rfgt liquid level: -8 -4 mm
---------------------------------------------------------------------------------------
at 10:50 am (SEP 27,2011)
Modes
chiller mode: Running
circuit 1 mode: stopped by Low Evaporator Rfgt Temp-Ckt1 at 10:30AM
cprsr1A mode: Auto
cprsr1B mode: stopped (comm. Loss: Starter 1B)
circuit2 mode: Running
cprsr2A mode: Running
Chiller
Evap leaving water Temp: -6.9c
Evap Entering water Temp: -5.3c
outdoor air temp: 29.2c
compressor
1A
Amps L1 L2 L3 : 0.0 0.0 0.0
%RLA L1 L2 L3 : 0.0 0.0 0.0
unit volts : 415
oil Temp: 30.9c
Intermediate oil pressure: 116kpag
suction pressure: 113kpag
2A
Amps L1 L2 L3: 140.0 135.0 130.0
% RLA L1 L2 L3: 71.6 69.0 67.0
Oil Temp: 62.4c
Intermediate oil pressure: 933kpag
Suction pressure: 101kpag
Rfgt ckt1 ckt2
Cond Rfgt pressure: 669 1021 kpag
Sat cond Rfgt Temp: 29.9 43.3 C
Evap Rfgt pressure: 113 102 kpag
Sat Evap Rfgt Temp: -8.4 -9.7 C
Evap Approach Temp: …… 2.7 C
Rfgt liquid level: -15 0 mm
---------------------------------------------------------------------------------------
at 12:04PM (SEP 27,2011)
Chiller
Evap leaving water Temp: -6.8c
Evap Entering water Temp: -4.9c
outdoor air temp: 28.7c
compressor
1A
Amps L1 L2 L3 : 68.0 64.0 61.0
%RLA L1 L2 L3 : 50.4 47.6 44.6
unit volts : 408
oil Temp: 32.7c
Intermediate oil pressure: 653kpag
suction pressure: 70kpag
2A
Amps L1 L2 L3: 141.0 135.0 129.0
% RLA L1 L2 L3: 71.6 68.5 66.2
Oil Temp: 62.1c
Intermediate oil pressure: 924kpag
Suction pressure: 105kpag
Rfgt ckt1 ckt2
Cond Rfgt pressure: 708 1009 kpag
Sat cond Rfgt Temp: 31.7 43.3 C
Evap Rfgt pressure: 110 105 kpag
Sat Evap Rfgt Temp: -8.7 -9.3 C
Evap Approach Temp: 1.8 2.5 C
Rfgt liquid level: 3 1 mm
---------------------------------------------------------------------------------------
at 12:13PM (SEP 27,2011) circuit 1
Low Evaporator Rfgt Temp-Ckt1
1A
Amps L1 L2 L3 : 0.0 0.0 0.0
%RLA L1 L2 L3 : 0.0 0.0 0.0
unit volts : 410
oil Temp: 51.3c
Intermediate oil pressure: 50kpag
suction pressure: 48kpag
1A at 12:18 PM
Amps L1 L2 L3 : 68.0 64.0 61.0
%RLA L1 L2 L3 : 50.5 48.0 44.5
unit volts : 411
oil Temp: 58.1c
Intermediate oil pressure: 676kpag
suction pressure: 69kpag

1A at 12:21 PM
Amps L1 L2 L3 : 67.0 64.0 61.0
%RLA L1 L2 L3 : 50.3 47.5 44.5
unit volts : 411
oil Temp: 60.6c
Intermediate oil pressure: 651kpag
suction pressure: 48kpag

1A at 12:22 PM
Amps L1 L2 L3 : 68.0 64.0 61.0
%RLA L1 L2 L3 : 50.8 47.5 44.0
unit volts : 404
oil Temp: 61.3c
Intermediate oil pressure: 680kpag
suction pressure: 131kpag
---------------------------------------------------------------------
at 2:57 PM (SEP 27,2011)
Modes
chiller mode: Running
circuit 1 mode: stopped by Low Evaporator Rfgt Temp-Ckt1 at 12:41 PM
cprsr1A mode: Auto
cprsr1B mode: stopped (comm. Loss: Starter 1B)
circuit2 mode: Running
cprsr2A mode: Running
Chiller
Evap leaving water Temp: -6.7c
Evap Entering water Temp: -5.2c
outdoor air temp: 28.9c
compressor
1A
Amps L1 L2 L3 : 0.0 0.0 0.0
%RLA L1 L2 L3 : 0.0 0.0 0.0
unit volts : 407
oil Temp: 32.3c
Intermediate oil pressure: 132kpag
suction pressure: 129kpag
2A
Amps L1 L2 L3: 138.0 134.0 129.0
% RLA L1 L2 L3: 70.2 68.2 65.5
Oil Temp: 61.2c
Intermediate oil pressure: 916kpag
Suction pressure: 105kpag
Rfgt ckt1 ckt2
Cond Rfgt pressure: 666 1017 kpag
Sat cond Rfgt Temp: 29.9 43.6 C
Evap Rfgt pressure: 127 104 kpag
Sat Evap Rfgt Temp: -6.7 -9.5 C
Evap Approach Temp: …… 2.8 C
Rfgt liquid level: -8 -1 mm
---------------------------------------------------------------------------------------

[chillerman2006]

Hi CoolKing

lets see if we can diagnose this for you

All the readings need to be taken manualy and not off the controller

Need to know what refrigerant first ?

Then allow chilled water temperature to rise enough to call for compressor to run at full load 100%

Now at full load (no saturated temperatures - actual real temperatures)

List the answers to these conditions below

Water or Air cooled condensor

If air cooled - air on & air off
If water cooled - water in & water out

Ambient temperature

Discharge pressure
Discharge temperature
Condensor outlet temperature
Liquid line temperature (after the drier)

Suction pressure
Suction temperature

Evaporator temps/pressure taken through binda point

Water in
Water out
Water return pressure
Water flow pressure

R's chillerman

[serviceman]

could you give me the complete model of the machine? if it's 250TR has two circuits each circuit with a compressor.

[sweimaker]

you need an engineer there simple

long list of possible problems. refrigerant is the last thing you want to look at and one of the most expensive.

no one can actually help without you having the right tools, besides fgas rules

[cool king2007]

could you give me the complete model of the machine? if it's 250TR has two circuits each circuit with a compressor.

Hi serviceman,
The machine is Air Cooled Series R^TM Helical-Rotary Liquid Chiller, Model RTAC250, Fluid R134a, with two circuits first one has two compressors 1A,1B. Second one has one compressor 2A.
our problem with the first circuit that is compressor 1B stop by Comm loss: starter 1B and this is ok because we are waiting for STARTER MODULE for this compressor. But compressor 1A trips by Low Evaporator Rfgt Temp-Ckt1 and sometimes by Low suction Rfgt pressure-Ckt1.

please let me know For further information

Thanks

[cool king2007]

you need an engineer there simple

long list of possible problems. refrigerant is the last thing you want to look at and one of the most expensive.

no one can actually help without you having the right tools, besides fgas rules

Thanks for your advice, and i am here trying to solve the problem

[chillerman2006]

Hi CoolKing

lets see if we can diagnose this for you

All the readings need to be taken manualy and not off the controller

Need to know what refrigerant first ? R134a

Then allow chilled water temperature to rise enough to call for compressor to run at full load 100%

Now at full load (no saturated temperatures - actual real temperatures)

List the answers to these conditions below

Water or Air cooled condensor

If air cooled - air on & air off
If water cooled - water in & water out

Ambient temperature

Discharge pressure
Discharge temperature
Condensor outlet temperature
Liquid line temperature (after the drier)

Suction pressure
Suction temperature

Evaporator temps/pressure taken through binda point

Water in
Water out
Water return pressure
Water flow pressure

R's chillerman

Thanks for your advice, and i am here trying to solve the problem

Cool king

answer all the above questions and first to see it will be able to help you

am on here most nights myself

R's chillerman

[serviceman]

COOL KING:

The Starter Module did not receive a transition complete signal in the designated time from its command to transition. The must hold time from the Starter Module transition command is 1 second. The Must trip time from the transition command is 6 seconds. Actual design is 2.5 seconds. This diagnostic is active only for Y-Delta, Auto-Transformer, Primary Reactor, and X-Line Starters.

[serviceman]

This is a specific starter test where 1M(1K1) is closed first and a check is made to ensure that there are no currents detected by the CT's. If currents are detected when only 1M is closed first at start, then one of the other contactors is shorted.

LOW TEMP EVAP.


(calculated from suction pressure transducer dropped below the Low Refrigerant Temperature Cutout Setpoint for 1125°F-sec with a 8°F-sec/sec max integral rate applied during circuit startup transient (or 4ºF-s/s if manifolded and only one cprsr running) while the circuit was running early in the circuit’s cycle. The minimum LRTC setpoint is -5°F (18.7 Psia) the point at which oil separates from the refrigerant. During the time that the trip integral is non zero, the unload solenoid(s) of the running compressors on the circuit, shall be energized continuously and the load solenoid shall be off. Normal load/unload operation will be resumed if the trip integral decays to zero by temps above the cutout setpoint. The integral is held nonvolatily though power down, is continuously calculated, and can decay during the circuit’s off cycle as conditions warrant.

LOW PRESS EVAP:


a. The Suction Refrigerant Pressure (or either of the compressor suction pressures) dropped below 10 Psia just prior to compressor start (after EXV preposition). b. The pressure fell below 16 Psia while running after the ignore time had expired, or fell below 10 Psia (or 5 Psia in sftw prior to Oct’02) before the ignore time had expired. The ignore time is function of outdoor air temperature. Note: Part b. is identical to Low Evaporator Refrigerant Temperature diagnostic except for the trip integral and trip point settings.

QUESTION:

have changed the initial charge of oil?