Reply to Thread

[quote=always looking;7631732]Just curious why you would have to cange the oil, all RTAAs come from the factory with OIL31 even though the nameplate says OIL 15. [quote]

I agree that all RTAA compressors are factory charged with OIL0031 and the service replacement oil is Oil 0015 unless evaporator leaving water temperature is < 38F. For water temperatures < 38 F Oil 0031 is the recommended service replacement oil, it is a Naphtehenic refined mineral oil with anti-foaming additives.

With the chillers in question ranging in age from 9 to 17 years old there would be a question if the oil is still the original factory charge of OIL0031 or if the charge has been topped up or replaced with OIL0015. I guess a sample could be taken and refractive index checked to verify.

rnr07 - For low temp operation would also suggest the EXV Gain Compensation is enabled (Menu # 52) but more importantly and following on from ChillerWhisper’s question on how low do you want to go? Would recommend if you are looking a <40F LWT set-point requiring operation on glycol you get someone involved that is experienced on these chillers as not only will you have a capacity reduction but your flow/pressure drop will also change. The chiller has to operate above it’s the minimum flow rate or you will be replacing the barrels before too long.

Just curious why you would have to cange the oil, all RTAAs come from the factory with OIL31 even though the nameplate says OIL 15. They did that to avoid confusion at the factory. They didn't want any OIL15 getting into a RTHB that was a low temp machine.

If you are going to run it below 38LWT you need to change the oil . Read the IOM .

I love RTAA's.

Originally Posted by rnr07

Oh I see that you were pointing me in the direction of this thread on page 4 of the chillers forum:

http://hvac-talk.com/vbb/showthread.php?t=547222

That thread was geared towards RTAC chillers. Given that these are RTAAs, is it true that I have to get Trane to do the software change? Is this because it takes a special interface to make changes to the module? Since I want to do this to so many chillers, I would be fine with buying the software/hardware to do this, I just need some input on what all it would take to make the change.

Thanks for all the help so far.

Just how low are you planning on running them? Are you going to use them for ice building or just running a lower chilled water supply temp? You can go down to 40 deg chwtr supply with no changes other than lowering the setpoint. Any lower than that, you'll have to run a glycol mix (this is where the biggest factor in derating of unit tonnage comes in due to the lower heat transfer coefficient of glycol--the higher the percentage, the lower the tonnage) and lower the lvg chwtr temp cut out and low ref evap temp cut out. If you want to build an ice bank, you need the options module (1U2) and have a relay to close the ice build contacts on the module and controlled by your BAS. Termination of ice build is controlled by setting the return fluid temp (usually around 26 deg) cutout which is activated when the options mod puts the unit in ice build mode. The RTAA still uses the existing oil cooler when used for low temp and no auxilliary cooler is needed. It ain't rocket science and RTAA's are almost ready to run low temp out of the box, but there are a few changes that need to be made depending on type of service (ice build or just lower than normal chwtr supply)

Oh I see that you were pointing me in the direction of this thread on page 4 of the chillers forum:

http://hvac-talk.com/vbb/showthread.php?t=547222

That thread was geared towards RTAC chillers. Given that these are RTAAs, is it true that I have to get Trane to do the software change? Is this because it takes a special interface to make changes to the module? Since I want to do this to so many chillers, I would be fine with buying the software/hardware to do this, I just need some input on what all it would take to make the change.

Thanks for all the help so far.

Originally Posted by cri3541

Page 4 I believe

What do you mean page 4?

Originally Posted by rnr07

I have six RTAA chillers I would like to convert to lo-temp. I've been told by a few people that the conversion is only a software change-up and a relative reduction in tonnage. Does anyone have any input on what the most economical way to do this across multiple chillers is?

Page 4 I believe

My email is rnreuter@gmail.com

All of the RTAAs I am interested in converting to low-temp have the standard Trane Adaptive Control display. They are RTAAs ranging in year from 1993 to 2001.

what's your email

so it is needed is needed adicional.ya oil cooler temperatures than by evaporation and condensation to ice maker or brine is necesario.enviame the type of display that has the machine

How do I go about modifying the programming? Is this something that could be done using the controls on the machine or will I have to plug a laptop in and do some sort of ladder logic change? If so, what cable and interface program do you use for something like this?

Also I was under the impression that the oil cooler for RTAAs is in the top portion of the coils. Will this now require additional oil coolers?

would have to modify the programming of the machine, use glycol intoaccount takes a loss of capacity of the machine would have to install an oil cooler for compressors

Converting a Trane RTAA from standard leaving temp to low temp

I have six RTAA chillers I would like to convert to lo-temp. I've been told by a few people that the conversion is only a software change-up and a relative reduction in tonnage. Does anyone have any input on what the most economical way to do this across multiple chillers is?