is there a replacement chart here

[primmers]

that shows what freons to use when doing a change out?

im replacing a 502 system, and the new compressor is listed as 502/404..the new expansion valve says 404,502,402a and 507..nothing about 408a..

whats up?

[Edited by primmers on 07-07-2005 at 10:18 PM]

[Dad]

http://www.refron.com/InfoCenter/TechnicalData.asp

[primmers]

garcia..

[selfemployed]

http://www.dupont.com/suva/na/usa/literature/pdf/h71061.pdf

[rayr]

It may not be mfg specs. butttttttt I have used 408-a with MO in close coupled systems where the evap is above the condenser with 0 problems. Im talking about 50 systems that were done in 96 and are still running strong. Dont think I would use it on long runs without changing the oil to AB. OMO and past experience.

[primmers]

this compressor is on the roof right above the evaporator..

[Dad]

primmers.. i guess we have been dancing all around what you are trying to get... that is, some info on a 408 system.

502 converts with 408a cause it uses the same oil. It is a drop in for 502 basically with just slight temperature glides.

Any time you see a TXV for 502 you can use 408 and 404.

Your compressor being on top of your evap will not be a problem for oil return. You would need a trap installed for every 20' of vertical lift of suction line.

With the conversion of 502 to 408 you will have very little change in superheat settings with your TXV.

[primmers]

the thing that got to me was there was
no mention of 408 on the txv or compressor..
but since 408 is a mid term freon, i guess the
manufactures wont mention it..

ive done a couple 502 to 408 before, but wondered aloud here about the ignoring of the product(408) on parts..

also i wonder why manufacures still use r12 as a standard..
why not design condensing units to handle the higher head pressure for example..

[condenseddave]

Look at a PT chart, and you'll see that 408A and 502 are virtually identical.