Carrier 19XL/XR to York VFD/Optiview Conversion

[Shophound]

Last week I went to another facility to check out a Carrier 19XL that had been converted to variable speed with a York VFD, and PIC panel replaced with York Optiview. Local JCI did retrofit. Rep pointed out mods to allow entering condenser water temp (ECWT) down to 55°F during low load operation to save $$ and would not create oil return problems. Said VFD capability only partially responsible for energy reduction realization, that lowering ECWT during part load operation is other vital component to reduce $$.

Talked to chief engineer of facility and he seems pleased with conversion. Has seen operating costs go down and is expecting about a three year payback on the conversion. I was impressed with the Optiview panel, a light year ahead of the PIC II panels on my 19XR machines as far as ease of use and presentation of vital info goes.

We have been considering various energy optimization strategies or one of our 19XR chillers (and central plant) for some time, now. We've entertained options for a Carrier VFD conversion (essentially turning our 19XR into a 19XRV) to outright replacing the chiller with a reduced tonnage York YK VFD or McQuay w/Turbocor (oil free) machine. While the Turbocor option seems quite inviting, our existing 19XRs are just nine years old. To rip out a machine with approx. 25k operating hours logged seems a waste if effective VFD conversions are available that render decent payback schedules. Since our plant operates 24/7/365, part load operation with our present constant speed machines is a killer, with chiller kw per ton often exceeding 1.0 (chiller motor amps alone, not counting pump and tower energy use).

Would appreciate any feedback from folks in our new chiller forum concerning constant speed chillers converted to VFD, and how effective such are in real time for reducing overhead.

[stickerhead]

I am also from the LS State and have both types of chillers under contract. The Carrier 19XR's will not turn down like a York will. I have had YK Yorks running 30Hz with 55 degree tower water. Lowest I have seen Carrier's is 48 HZ. But there is 23% energy savings in the first 5 Hz ( 60 to 55). The issue with a Carrier would be oil loss in the seals and motor cooling. You may have to adda refrigerant pump to handle it. I know a York engineer that has gotten around some of this by adding his own little goodies.

[justjohnson]

I have heard McQuay techs brag that they can retrofit old centrifugals with their Turbocor compressors - that might be an option. I believe they only go to 300 tons however.

[pecmsg]

I looked into VS drives for my units but at 2400 volts that’s not an option.

Carrier has since replaced the PIC II controllers with there 32XR that has the VS option built in and i-Vu. (that’s another story) If it can be used on your units well Carrier will have to sign off on it.

On thing I’ve learned is with Carrier, always check with them first to see if the unit can handle it.

Good Luck

[stickerhead]

I looked into VS drives for my units but at 2400 volts that’s not an option.

Carrier has since replaced the PIC II controllers with there 32XR that has the VS option built in and i-Vu. (that’s another story) If it can be used on your units well Carrier will have to sign off on it.

On thing I’ve learned is with Carrier, always check with them first to see if the unit can handle it.

Good Luck

You can but not thru Carrier. Rockwall/Reliance makes medium voltage drives

[Randy S.]

The optiview is cool, but won't change the 42Hz minimum speed on the compressor.
You might not be able to go that slow, depending on your machine and application.
All kinds of different combinations of compressors, wheels and shells.

I'd stick with Carrier, and have them help engineer.

[yorktek37]

York/JCI has a damn good MV/VSD. The size is not too bad either. We may be retrofitting a few places from steam to electric drive and using these.

[techtalker]

Carrier now sells the Rockwell Allen Bradley Medium voltage drive through the service division. so 2400 volts is possible, just a lot more expensive than the typical low voltage VFD. There is still a lot of payback, and with some states giving back a lot of $ for green solutions, a new drive can still give a good payback.

[chiller rob]

Benifits:
(see the picture)

reduced maitenance savings...
variable speed/ oil free/ frictionless...
iplv performance at 0.385 or so KW/Ton...
no oil issues ever again...
increased system redundancy...
excellant with variable chilled and/ or condenser water flow...
can run entering condenser water temps up up to 85f for significant water
savings at most load condtions...
no more mandatory cold condenser water to stay out of surge...
staged compressor flexibility... no more pony chiller...
low acoustic signiture... 70 db...
existing chiller upgrade with out mandatory mechanical room upgrades...
excellant way to convert existing equipment from R22 to R134a...
compressor service does not require full system shut down...
controllers available to run 6 or more compressors in tandam...
5 year compressor parts warranty available...
new chiller performance without the installation costs...

This is a 465 ton Carrier 19XL R22 machine that was land locked...
eddy current was performed to verify tube condition...
after the compressor demo was completed, three 140 ton turbocor compressors were installed...
the shell modifications are asme certified...
the R22 to R134a refrigerant conversion was accomplished by changing the linerear float...
it has been in service for well over 2 years and runs great...
we can take our part load performance to 35 tons and pull 30 amps...
it may not be for everyone but our customer likes the product very much...

Chiller Rob

[Randy S.]

Rob, you guys do some fine looking work.

[chiller rob]

Thanks Randy!

[york56]

There is a company by me that also does those type conversions they are cool.

[Shophound]

My thanks to everyone who has replied to this thread. I have seen the 19XR to Turbocor conversion pics on the web before; it was also a facility out in California, I think somewhere in San Diego. I'm not aware of anyone doing this in the DFW Texas area, but that does not mean nobody is. The idea of multiple VFD compressors that can be isolated from the barrels for service is appealing, along with the oil-free aspect.

The JCI/York VFD conversion on the 19XL I mentioned in the OP has mods that allow ECWT to be run as low as 55°F during part load ops. Not sure what kind if IPLV numbers they claim but will get that info. While the Turbocor conversion certainly has advantages over the JCI proposal, it may come down to cost since the Turbocor conversion appears more drastic than the JCI mod.

[Randy S.]

It's still the Carrier compressor. I'm told 42Hz is the bare minimum, for bearing reasons.

[stickerhead]

Benifits:
(see the picture)

reduced maitenance savings...
variable speed/ oil free/ frictionless...
iplv performance at 0.385 or so KW/Ton...
no oil issues ever again...
increased system redundancy...
excellant with variable chilled and/ or condenser water flow...
can run entering condenser water temps up up to 85f for significant water
savings at most load condtions...
no more mandatory cold condenser water to stay out of surge...
staged compressor flexibility... no more pony chiller...
low acoustic signiture... 70 db...
existing chiller upgrade with out mandatory mechanical room upgrades...
excellant way to convert existing equipment from R22 to R134a...
compressor service does not require full system shut down...
controllers available to run 6 or more compressors in tandam...
5 year compressor parts warranty available...
new chiller performance without the installation costs...

This is a 465 ton Carrier 19XL R22 machine that was land locked...
eddy current was performed to verify tube condition...
after the compressor demo was completed, three 140 ton turbocor compressors were installed...
the shell modifications are asme certified...
the R22 to R134a refrigerant conversion was accomplished by changing the linerear float...
it has been in service for well over 2 years and runs great...
we can take our part load performance to 35 tons and pull 30 amps...
it may not be for everyone but our customer likes the product very much...

Chiller Rob

Show off! LOL

[CaptJackSparrow]

What kida $$$$ for the conversion? Looks like a job well done!

[chiller rob]

Capt Jack...

i appreciate the question but it would not be proper for me to discuss that...

i will say this...

this technology is not about a compressor change out... it is a system upgrade or enhancement idea...

think about any system and ask what would or could be possible if the compressor(s) had the ability to unload to 10% or even 5% demand...

all the rules change when you can reduce the lift, slow your velocity and you dont have to return the oil... at low loads you can literally watch the liquid refrigerant moving thru the ll sight glass...

these retrofits (chiller conversion or DX retro) are not cookie cutter and each retrofit with its system complexities needs to be evaluated, engineered and estimated individually...

thank you,
chiller rob

[HVAC9900]

Good looking install/retro Rob.

So which float did you end up using?

[chiller rob]

9900,

we used a float for an XR same tonnage range...
they are all the same except for the lenghts and width of the slots...
it is interesting to hold the R22 valve next to the 134a and see the differance in flow between the two refrigerants...
i would estimate the 134a to have about 1/3 more flow...

Thanks all for the comments...
Rob

[yorktek37]

If your looking for that much of a turndown the Turbocor would be the way to go. It would certainly more efficient with the fact that there would be no oil either. as far as a vsd the flow curve on the carrier wheel would probably drop out around 35 hz plus you still need some rotational speed for the bearings to float properly. I would go with the turbocor. It would be a hell of a lot less to maintain also.