RTHA R22 Retrofit

[DANI25486]

Hi. As some of you know, in European Union after 2015, units woking with R22 will be forbidden. In the case of TRANE RTHA does anyone change de fluid?

[valdelocc]

Chillers with flooded evaporator are very difficult to retrofit.

[DANI25486]

This chiller have is a semi-flooded evaporator, its typical from the centravacs from Trane. This ones have a expansion orifice before the evaporator. And the difficult of retrofit on this machines is exactly that one.
Let´s see if anyone already changed the R22.

[valdelocc]

I have been talking to engineers from some of the refrigerant companies and they all advise not to use a zeotropic blends with flooded evaporators, we are stuck with r-22 in such applications till the next flavor of the month arrives.
Keep on posting your findings.

[DANI25486]

Well for that purpose you already have a good blends with no glide such R507, and R434a with 1,5ºC.

We already retrofit an RTHA300 with R434a, but its been difficult to get the correct size of both expansion orifices. the new refrigerants have a bigger molecular weight traducing to higher mass flow.

[valdelocc]

Well for that purpose you already have a good blends with no glide such R507, and R434a with 1,5ºC.

We already retrofit an RTHA300 with R434a, but its been difficult to get the correct size of both expansion orifices. the new refrigerants have a bigger molecular weight traducing to higher mass flow.

besides the two orifices what else did you change? why was the high mass flow rate a problem?
The pressure-temperature of r434a differs by a lot compared to r22, why did you pick that particular refrigerant?
in the US some customers want to leave r22 behind, we have lots r22 replacements in the market, I'm not crazy about any of them.
I dont think you'll find anyone here that already retrofitted a chiller from r22 to ???, hvac-talk is a small internet forum, my guess would be that around 10% to 15% of all US techs visit this site. very few adventurous minds, most here adhere to standardized methods if you know what I mean.

[absrbrtek]

very few adventurous minds, most here adhere to standardized methods if you know what I mean.

I dont fit into that catagory! Im game for trying anything new as long as I can justify that it will work, makes the job fun. For puposes of this discusion, the RTHA is a flooded evap. The refrigerant is on the outside of the tubes. I have not heard or seen any R22 replacement that wont cause fractionazation in the evap. There may very well be one out there. JMHO

[CV_Geardrive]

Hi Carlos,
The retrofit of this unit can be made only with R134a.
You will have 70% of cooling and 65% of power input.
Your local sales office will make a selection for you. If they can’t help you ask them to check the TRANE CARE retrofit program.
You should change current transformers (and adjust OVL, and condenser limit settings of control), oil and oil filters (about 5 times).
You may also need to adjust water flows.
According to a program (TRANE) no orifices and no O’rings need to be replaced.
According to compressor size you may gain another 5% of cooling capacity if you open the compressor and remove a spacer which limits the move of slide valve.
Regards,
CV

[absrbrtek]

Interesting. I changed older Trane recips from R22 to R12 at that time. Aircooled with 1 100 Ton recip in them. Really did not have to change anything on the chiller. a few control settings. The reason it was changed was becuase Trane had twice the run time before compressor inspections on R12 vs R22.

Hi Carlos,
The retrofit of this unit can be made only with R134a.
You will have 70% of cooling and 65% of power input.
Your local sales office will make a selection for you. If they can’t help you ask them to check the TRANE CARE retrofit program.
You should change current transformers (and adjust OVL, and condenser limit settings of control), oil and oil filters (about 5 times).
You may also need to adjust water flows.
According to a program (TRANE) no orifices and no O’rings need to be replaced.
According to compressor size you may gain another 5% of cooling capacity if you open the compressor and remove a spacer which limits the move of slide valve.
Regards,
CV

[sargent york]

The Multi-stack folks claim little loss by retro fitting to turbocurs and 134a, this may be a alternate solution for you. We are going to do a study on two RTHA for just this type of conversion. Regarding adventurous refrigeration mechanics? we are limited only by our customers pocket book!

[DANI25486]

Hi, as you know we retrofit this machine (RTHA300) to R434a, since, the unit works 24 hours/day, it works with good preformance, it had leak on oil thank house and a bad load solenoid however last week I notice a mechanical noise....it looks like some bearing seized.
I think this compressor have +/- 80.000h and it´s time for an overhaul.

Is ther anyone who made it on this compressor CHHA280 and be abble to share the manual information.

Tks in advance.

[WYLBEK]

Hi, as you know we retrofit this machine (RTHA300) to R434a, since, the unit works 24 hours/day, it works with good preformance, it had leak on oil thank house and a bad load solenoid however last week I notice a mechanical noise....it looks like some bearing seized.
I think this compressor have +/- 80.000h and it´s time for an overhaul.

Is ther anyone who made it on this compressor CHHA280 and be abble to share the manual information.

Tks in advance.

There is no overhaul books or manuals for RTHA screw machine. Trane has rnewal program to either rebuild yours or send you a rebuild compressor. If it is truly bearings and no damage to male or female rotors you can replace bearings in the field. They are SKF bearings and can be purchased through bearing rep. If you have opened up a centrifugal machine before this is easier.

[DANI25486]

Thanks WYLBEK for sharing. And how about the seal between motor and screw rotors, does Trane sell it??

[WYLBEK]

Thanks WYLBEK for sharing. And how about the seal between motor and screw rotors, does Trane sell it??

Yes, find rnewal parts list at Trane rep. Big o-rings mostly and a few gaskets.
Good luck

[DANI25486]

I´ll do that, as soon as the job is done I´ll kep this post updated. Tks.

[DANI25486]

Hi, the job is almost done. The compressor is assembled and it just missing the mounting of the oil separator and his housing.

When I was assembling the piston of the slide valve I came to a doubt; this compressor have 3 springs, all of them together have a lot of force. I think that with such strength, the piston can´t fully load the slide valve. This chiller was made to work with R22 and because of the legal ambient issues, now it´s with R434A.

I assembled the piston without the weaker spring. I think that it will work a little bit more rough, but with a better performance/loading.

I´m seeking help for the ones that know these machines, if this procedure is ok or if I´ll have problems in the future.

Thanks.

[DANI25486]

Please guys, I really need to close the oil housing on monday, but I also wanted to be more confident on this modification.

[Dilp172]

In regards to the spring I would put it together as originally assembled, the pressures will be similar , thanks for posting the pictures and your progress.Here in the US Trane keeps all there info closely guarded.
It's creepy how protective Trane guys are about there chillers , pretty laughable
Good luck keep posting pictures !

[DANI25486]

Hi guys, I´m going to do a retrofit on RTHA215 from R22 to R134a, as it was said before on this post, TRANE recomends to change the current transformers. Can anyone clarify me why is it needed?

Thanks in advance.

[WYLBEK]

On this RTHA does it have old black box control panel?