Compressor Excessive Run at High Altitude

Compressor Excessive Run at High Altitude - Printable Version

+- Newell Gurus (https://newellgurus.com)
+-- Forum: Technical Discussions (https://newellgurus.com/forumdisplay.php?fid=3)
+--- Forum: Air Conditioning (https://newellgurus.com/forumdisplay.php?fid=8)
+--- Thread: Compressor Excessive Run at High Altitude (/showthread.php?tid=4295)

Compressor Excessive Run at High Altitude - rwatts7777 - 06-12-2018

Have just spent 10 days in the Rockies above 7000 feet.
The 110v compressors ran excessively hard while there. I had to manually turn on the compressors and then turn them off to avoid an "excessive run" situation.
I know the compressors lose about 20% of their effectiveness above 5000 feet.
Does anyone have a better solution? I'm told by Newell that I can not adjust the "on" "off" PSI of the compressor.
Any suggestions? Am now in Kansas and all seems to be back to normal.
Richard

RE: Compressor Excessive Run at High Altitude - encantotom - 06-12-2018

i had our 02 at our cabin this spring for 2 weeks and it is at 7000 feet. i had no issues with my 120v compressor. ran normally.

as for adjusting on off of the compressor psi, all it is is a common square d well pump switch. i dont think they make many of them you cannot adjust. you can take the gray box cover off (after the power is turned off for the compressor) and if there is one screw with a nut on it, that is the one you can adjust the cut in psi. they mostly have a 20psi differential so if you adjust it up or down the differential of 20psi remains the same. if there are two adjustment nuts, the smaller one adjusts the differential.

i would more wonder if the lower temps at altitude are exaggerating any air leaks you might have. or were you using more air for any reason?

although, i am not sure why you would want to adjust the pressure.

tom

RE: Compressor Excessive Run at High Altitude - Richard - 06-13-2018

Tom,

When I looked at Richards compressor setup, it looks like the compressors are now controlled by the Valid system. I did not see the classic well pump switch.

My best guess is that the compressors may be showing some early signs of wear, and that the lower barometric pressure at altitude puts the upper cutoff pressure at the limit of their capability. Richard, if this were the case then the compressors would have gotten to some number below their upper set point and just held that pressure while they ran and ran. Is that what happened?

If it were an exacerbated air leak, then the compressors would have cycled more frequently, but would reach the cutoff point and stopped.

RE: Compressor Excessive Run at High Altitude - encantotom - 06-13-2018

so there are two 120v compressors in the valid setup?

tom

RE: Compressor Excessive Run at High Altitude - Nebster - 06-15-2018

In mine there are two identical 120V compressors, manually switchable. There is no 12V compressor.

The compressor controller doesn't have anything to do with Valid. It does seem set to maintain a higher range of PSI than the ones a lot of you guys with older coaches mention. There was no obvious user-friendly way to change the pressure settings on mine, although I didn't try disassembling the box to look inside. (As someone mentioned, not sure why we'd want to do that.)

If it matters, I had BOTH compressors die almost simultaneously after six months at 6,000 feet. They were both 10 years old and had ~2,500 hours on each. The new compressors did not seem to have any trouble compressing at that altitude relative to sea level. I have been watching the timing pretty closely, because (a) I replumbed them with polyethylene tubing and that was a disaster, and also (b) I have had a ton of leaks develop.