12-08-2012, 03:36 PM
Steve contacted me about getting additional details on the relay used to control the solenoid at the bottom of the auxiliary air water separator. I thought that would be an easy request to handle. Now I am plenty confused about how all the controls on my coach work together on this system.
My basic understanding is unchanged. That is, when the compressor runs, the solenoid on the separator is energized and it closes the valve so the water cannot drain out or the air escape. When the setpoint is reached and the compressor shuts down, the relay is de-energized, the power removed from the solenoid on the bottom of the separator, and the valve within is opened, letting the water and air drain.
What is confusing now is there are two ways to turn the compressor on, and that was a surprise. There is a pressure switch with contacts that turn it on, and there is a contactor in its own little box with the solenoid relay that will also turn the compressor on. Either one operates the relay correctly and air and water escape at the end of the cycle. It appears that the pressure switch is what starts and stops my compressor. If I manually close the other contactor it starts and stops as well. What I don't know is what might make the other contactor ever pickup. I just forced it closed with an insulated probe and the compressor ran. I actually expected it would close when the pressure switch called for air, but it didn't. If any of you know why there are two separate ways to run the 115vac auxiliary air compressor, please let us know.
The relay that controls the draining of the separator is a Potter and Brumfield general purpose relay P/N KHAU-17A18-120. It has four form C contacts, only two of which are used. The coil is 120VAC and gets power anytime the compressor gets power.
I have attached pictures.
Oh, one other mystery is the device just upstream of the pressure switch. It appears to be an adjustable air pressure regulator with nothing connected to the output port. You can see the adjustment on the pressure switch with its cover removed. Mine seems to start the compressor in the low 70's and stop it in the mid 80's.
Russ
My basic understanding is unchanged. That is, when the compressor runs, the solenoid on the separator is energized and it closes the valve so the water cannot drain out or the air escape. When the setpoint is reached and the compressor shuts down, the relay is de-energized, the power removed from the solenoid on the bottom of the separator, and the valve within is opened, letting the water and air drain.
What is confusing now is there are two ways to turn the compressor on, and that was a surprise. There is a pressure switch with contacts that turn it on, and there is a contactor in its own little box with the solenoid relay that will also turn the compressor on. Either one operates the relay correctly and air and water escape at the end of the cycle. It appears that the pressure switch is what starts and stops my compressor. If I manually close the other contactor it starts and stops as well. What I don't know is what might make the other contactor ever pickup. I just forced it closed with an insulated probe and the compressor ran. I actually expected it would close when the pressure switch called for air, but it didn't. If any of you know why there are two separate ways to run the 115vac auxiliary air compressor, please let us know.
The relay that controls the draining of the separator is a Potter and Brumfield general purpose relay P/N KHAU-17A18-120. It has four form C contacts, only two of which are used. The coil is 120VAC and gets power anytime the compressor gets power.
I have attached pictures.
Oh, one other mystery is the device just upstream of the pressure switch. It appears to be an adjustable air pressure regulator with nothing connected to the output port. You can see the adjustment on the pressure switch with its cover removed. Mine seems to start the compressor in the low 70's and stop it in the mid 80's.
Russ
Russ White
2016 Winnebago Vista LX 30T
#530 ( Sold )
1999 45' Double Slide - Factory upgrade 2004