Change over from R 502 to R 404A

[smpsmp45]

There are lots of units operating on R 502. Now everybody wants to change over to R 404A. What are the precautions to be taken?

Has anyone done this?

[paul_h]

different oil, and r404a is a r134a blend (3%), r507, without the r134a seems is better.
You could of just done a search, it's not like r404a is new. ie.
http://www.refrigeration-engineer.co...earchid=451099
search _>advanced_>r404a only in the title_>refrigeration and sub fourms only

[powell]

Here's a link to Copelands R502 to R404A changeover procedures.

http://www.hvacrinfo.com/cope_ae_bulletins/94-15.PDF

[smpsmp45]

Hi! Powell,

Excellent link. Many thanks