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Drew
07-02-2016, 04:06 AM
Hi all,

Im trying to convert an old r12 system to R404 and need to replace a failed old kelvinator open drive condensing unit .

Ive looked on the net but cannot find a capacity chart for the kelvinator Y72 model.

Does anyone know where i can get this info. Thanks.

Im lookinf for its capacity running at say -10 C suction. R12.

Thanks.

HVACRsaurus
07-02-2016, 07:36 AM
Hi Drew,

I'd suggest working from the evaporator capacity, if that is not available strip the Tx valve & cross reference the orifice rating..

Ps, if someone has compressor capacity, allowance will need to be made for shaft speed.

mikeref
07-02-2016, 08:18 AM
The old Kelvinator open drives. Solid as and now rare as hens teeth.
Diameter of motor pulley divided by diameter of compressor pulley, multiply by motor RPM's = compressor RPM.
If you are a Heatcraft customer, request their tech division to calculate the Y72 capacity at those revs on R12 @ -10 SST.

Magoo
07-02-2016, 11:33 PM
Geez Drew
I have not seen one them for decades , literally.
Actrol have a lot of old info on their web site, if that helps. Fairly sure they had Kelvinator open drives on there. I was looking for capacity of an old Muller evap.
All the same they are /were a brilliant compressor, slow and easy lasted for years, obviosly if you still have one running.

Drew
08-02-2016, 02:11 AM
Thanks the replies guys.
I have worked backwards fron the old muller evap. The issue with this is I'm not sure where the suction was based and this would influence the capacity of the coil, but as a rule of thumb I could have based the suction at -5c, but this capacity would not have matched the rooms needs. Room requires roughly 6kw. The coil offers 6.3 kW at 11 degree c temp diff. (2900w at 5 according to specs) Therefore for a 2 degree room temp I was thinking to base the condensing unit at -10c. It's just a bottle room so no issue with humidity. Will also fit carel with off cycle defrost. I have looked at the old actrol catalogue on there site and all I can find is the displacement per rev.( 41.5 Ci inch) I then chose a slow 500 rpm and then worked out corresponding cubic meters per hour. From that I've cross referenced a bitzer compressor with the same displacement and found that a capacity on r12. Seems to tie up at a -10 suction. I will contact actrol further to see if I've got it right. I would have to go to site to confirm pulley size and motor rpm.
The current txv offers 6 kW. So all looking good to balance at -10c.

im mainly doing this exercise to see whether this unit could be of a bigger capacity meaning it could be serving another coil in another room . I personally haven't been to site and the tech wasn't sure with all the old and new equipment whether this unit could have t ed off to another room, but with the workings I've done all seems to tie up for 6kw at -10c.

Thanks again.

mikeref
08-02-2016, 07:43 AM
Drew. Just a few issues. The Muller evaporator may be too old for adequate heat transfer using R404a.
The different working pressures might cause leaks on aged return bends.
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Magoo. I still have a few old Kelvinator open drives. K62, 72 and one T82. The old bellows shaft seals were changed to Rotary many years ago. Gone are the days when rebuilds were available.