Choosing trinary switch pressures

[andrew vanis]

Choosing trinary switch pressures

Since trinary switches are available in different trigger pressures - Some have a high pressure cut our at 490psi, some have the high cut out at 420psi. similar variance for fan trigger PSIs

So - What determines what trigger pressures to use? For both the low/high pressures and the fan pressures.

The question is general and comes from designing a custom 134a system.

Thanks in advance.