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Re: Adding high pressure switch to older unit help.

Posted: Sun Aug 27, 2023 8:54 am
by tbirdtbird
GM- "There needs to be a separate relay or diode in the circuit to avoid this." This is how I have always done this (relay), especially since these spal fans are easily drawing 12 amps

Re: Adding high pressure switch to older unit help.

Posted: Thu Aug 31, 2023 10:14 am
by Vetteman61
I stop receiving notifications on this thread and didn't realize there had been responses.

GM Tech, I agree, I also do not want the fans spinning when not needed, which is why I have determined the pressure sensor to be my best alternative. Would the sensor that went in the back of the old A6 compressors mount in the same port that I could purchase and have spliced into the high side of the AC line?

Re: Adding high pressure switch to older unit help.

Posted: Thu Aug 31, 2023 10:27 am
by Vetteman61
GMTech, I looked up the switch you mentioned. It was exactly what I had in mind, but it unfortunately didn't turn on at the PSI I needed. Thank you, however, as you're the first person to actually answer the question and provide the information rather than just tell me to do it a different way.

Even though the switch didn't fit in the correct PSI range, I was able to use some of the terminology on the specifications to help locate others. Do you believe this would be suitable for an automotive AC system?

(Link deleted)

Image

Re: Adding high pressure switch to older unit help.

Posted: Thu Aug 31, 2023 11:59 am
by JohnHere
JohnHere wrote: Fri Aug 25, 2023 6:36 am ... . Opinions vary, but setting the high (fans on) limit to around 250 PSI and the low (fans off) limit to around 190 PSI seems reasonable. ... .
Does the pictured pressure switch operate at or around the previously mentioned limits? If so, it can likely serve your intended purpose.