In searching the archives I've come up with posts that provide different answers, and I read through the HWH documentation and didn't find an answer. HWH tech support takes several days to respond.
Coach: 1998 U-320 36' non slide
HWH System: Series 600
When the HWH Series 600 system goes into sleep mode, what PSI has to be in the main air tanks before the 12 volt Aux compressor will engage to relevel the coach?
On our setup the Aux compressor does not fill the main air tanks on the coach.
Thank you,
Chris
The simple answer is this: when system pressure falls to approximately 85 psi.
Where did I find this info? There are two excellent HWH manuals available online for your enlightenment. Links provided below.
In the
HWH Systems Textbook, on page M140.019A (System Pressure Switches) you will read:
"Pressure switches used to monitor system air pressure are usually set at 85 psi, although some manifolds have a pressure switch set at 100 psi."I believe all Foretravel coaches use the 85 psi pressure switch, which is mounted on the
rear 6-pack manifold.
http://www.hwhcorp.com/ml20635.pdf
http://www.hwhcorp.com/ml13985.pdf
Hmmm.... Wonder if this rear pressure switch is what is preventing mine from pumping up the system to achieve level when main tanks are low on air???
I do have a contamination issue with desiccant from old compressor & dryer. (May have to bite the bullet and replace the wet tank)
Easy to check. Test the continuity on the two contacts on the pressure sender. Check with air system topped off, and with system depleted. Should be a change in continuity between tests. I can't remember if sender is normally open (NO) or normally closed (NC).