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auto leveling 12 volt air compressor?

Ok, So I'm dry camping and have the auto air level set. Does it use the 12 volt compressor to stay level and how much battery will it use,
Thanks
1996 U295-36, Cummins 300hp, 8.3. Build number 4864. Vin number 1F97D536XTNO54271. Purchased October 31, 2019.

Re: auto leveling 12 volt air compressor?

Reply #1 –
To answer your own question all you have to do is read the manual:  http://www.hwhcorp.com/ml11148.pdf

AUTOMATIC LEVELING
Set the park brake. Push the "AIR" button one time to turn the system on. Push the "AIR" button a second time. This will start automatic leveling. The following should occur:
a. The four red warning lights will be on.
b. The indicator light above the "AIR" button will start to flash.
c. The master warning light will be on.
d. The coach will automatically level itself. The leveling procedure is as follows:
If there are no yellow lights the control box will go directly into a sleep mode.
If there are yellow lights on, leveling will start in a down mode, deflating air bags opposite to lit yellow level indicator lights. After 2 minutes if the coach is not level, the computer will switch to the "UP" mode, inflating air bags according to lit yellow lights. During any raise (UP) function the compressor may run. When all the yellow lights are are out, the control box goes into the sleep mode.
SLEEP MODE: After leveling the coach the control box will remain on but inactive for 30 minutes. After 30 minutes the control box will wake up and monitor the yellow lights until leveling is needed. If a light is on or comes on and remains on for 60 seconds, the control box will relevel the coach using the original leveling procedure. After leveling the vehicle the control box will return to the sleep mode.
EXCESS SLOPE: During the leveling mode, either initially or after a sleep mode, if the coach cannot be leveled in 15 minutes the control box will stop all operations, and the "EXCESS SLOPE" indicator will come on. The box will will remain on until the "OFF" button is pushed, but will not go into a sleep mode.

How much battery it will use depends on how often the 12 volt compressor runs, which depends on how tight your air system is.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: auto leveling 12 volt air compressor?

Reply #2 –
My system it so air tight that my compressor hasn't turned on, so I don't even know if it works.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: auto leveling 12 volt air compressor?

Reply #3 –
To simply things, on auto level the system will DEFLATE air bags to level until there is <80 lbs of air pressure in your tanks. Once there, it will only level by using the aux compressor to add air to the BAGS. So depending on how much you  leak depends on how often it comes on. After 15 minutes if the little compressor has not leveled the coach, it will shut off.
1994 U280, Build 4490
Deming, NM.

Re: auto leveling 12 volt air compressor?

Reply #4 –
Got it thanks. I know how to use it, I just wondered how much juice it pulls. Twig, that explains why it deflates first and is normal, thanks again
1996 U295-36, Cummins 300hp, 8.3. Build number 4864. Vin number 1F97D536XTNO54271. Purchased October 31, 2019.

Re: auto leveling 12 volt air compressor?

Reply #5 –
Oldguy has n extremely rare FT, one with no air leks.

Twig, I don't recall reading about any part of the HWH level system that will shut the compressor off after 15 minutes if it is not level.  Maybe so but my first compressor ran for days until it was worn out. The coach was in the barn and plugged in.  Where did you see that?

The smaller HWH compressor that you have  is on a 15 amp circuit breaker. Mine uses 10 amps.

If you want to manage your level system manually, while the ignition is still on press the air button just once instead of twice.  Then turn off the ignition.  This leaves the level system on but in manual mode.  You can adjust the coach's level using the buttons to raise or lower  front/rear/left/right as needed.  The level system will not try to adjust itself and the compressor should not come on unless you make an up adjustment.  Try it out.

We get somewhere, switch into manual mode and level the coach.  A day or so later as temperatures stabilize we usually make a slight adjustment (usually letting air out of the driver's side).  Maybe once more several days later and we will generally be level enough for several weeks.  Maybe not perfect but close enough for us. Where we are now the pass side faces south and the sun warms the airbags on that side more than the other and we have made no adjustments yet.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: auto leveling 12 volt air compressor?

Reply #6 –
Quote from: Twig –
To simply things, on auto level the system will DEFLATE air bags to level until there is <80 lbs of air pressure in your tanks.  Once there, it will only level by using the aux compressor to add air to the BAGS
I must respectfully disagree with this statement.

It is my understanding that the HWH 600 Series automatic leveling program does not give a hoot about the air pressure in your tanks.  The only air pressure that would have any bearing on the auto level function is the pressure in the front air bags.  If the pressure in either front corner of the coach goes below 10psi then the associated pressure switch on the front 6-pack manifold will inhibit further lowering of the opposite corner.

In fact, the auto leveling program only cares about action and reaction.  The program does start out by lowering the coach - that is true.  But, the program only moves on to raising the coach when lowering is no longer effective.  It is easy to test this fact.  With the coach sitting at normal ride height and engine off, drain the pressure in all coach air tanks down to zero.  Then engage the Auto Level system.  If any yellow lights are showing on the HWH panel, the Auto Level program should lower the coach as required to put out the light.  System air tank pressure is irrelevant.

Once the Auto Level program finally moves on to raising the coach, it will run the 12V pump (if necessary) to supply the required air pressure.

The following quotes from the HWH Air Leveling Systems Textbook will back up my assertion:

https://www.hwhcorp.com/ml20635.pdf

"All air leveling programs are based on timed sequences and the yellow LEVEL lights. An example would be in one program a lower solenoid valve has to be on for 45 seconds or the yellow light has to go out before the computer will go to the next function. Times used to perform different functions is the main difference between programs."

"The most common leveling program is one where we first attempt to level the vehicle by lowering the high side or end of the vehicle. The computer will always level the vehicle side to side before leveling front to rear. If a side light comes on during front to rear leveling, the computer will stop front to rear leveling and level the vehicle side to side. After a set amount of time, usually 45 seconds, if the yellow light will not go out in the lower mode, the system will go into a raise mode. It will put air into the air bags for the side or end of the vehicle that is low, trying to put out the yellow light by raising the vehicle. Once the system goes into the raise mode it will not return to a lower mode."

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: auto leveling 12 volt air compressor?

Reply #7 –
Roger I have a leaks that I haven't been able to find. It leaks down to around 50 lbs overnight and then will stay there for days.
It's the leveling system that holds well and will stay put for days. At home I don't put on the auto leveling and it seems most
time I'm on the blocks as I am doing something under the coach.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: auto leveling 12 volt air compressor?

Reply #8 –
Quote from: oldguy –
1.  It leaks down to around 50 lbs overnight and then will stay there for days.
2.  It's the leveling system that holds well and will stay put for days.
1.  Protection valves on front and rear brake tanks are doing their job.  ^.^d

2.  Air bags and associated fittings and supply air lines are tight.  ^.^d
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: auto leveling 12 volt air compressor?

Reply #9 –
Yes it does. However, ON MY SYSTEM, at <80 psi on the gauge and with air still in the bags, it no longer dumps air to lower but the compressor comes on to raise the lower side. I can't comment on the HWH manual, only what I experience.
1994 U280, Build 4490
Deming, NM.

Re: auto leveling 12 volt air compressor?

Reply #10 –
Ok, my question would be. 
If I pull in somewhere and it's level where I park, so I just turn off the coach.  Now the HWH system isn't going to be active in this scenario.    Let's say there's small leak in a corner air bag,, does that leak affect air pressure in the whole system (  coach slowly lowers / leaks down to the stops )  or does that leak only effect the leaking corner of the coach (  leaking corner ends up with no air and rest of coach retaining pressure ) therefore putting the coach in a bind. 

  The answer may be in the manual or online but I'm looking for the forum opinions.
Robert and Susan
 1995 36' 280 WTBI 8.3 3060r
 1200 watts on the roof, 720 Ah of lithium's
 Build # 4637. Motorcade # 17599
        FMCA  # 451505
        18  Wrangler JLUR

Re: auto leveling 12 volt air compressor?

Reply #11 –
Quote from: Bob & Sue –
  or does that leak only effect the leaking corner of the coach 

Once the solenoid valve on the 6 pack closes (for any corner) from that point to the air bag should be a closed system.  Now you could have a seat leaking back in the 6 pack that you won't be able to find with bubbles.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: auto leveling 12 volt air compressor?

Reply #12 –
Quote from: Bob & Sue –
Ok, my question would be... 
In the situation you describe, if everything is working properly, you will only lose pressure in the corner with the leaking bag.

As Mike states, the closed "raise" solenoid valves (bottom 2 valves on 6-pack) prevent system air pressure from entering the "deflated" air bags.

In the case of the opposite situation, where the system air pressure drops to zero, the air bags will still hold pressure.  Both front and rear 6-pack manifolds each have 2 check valves.  These valves hold the pressure in the air bags when system pressure drops to zero.  You can see the white plastic check valves (with spring and O-ring + brass plug) in the photos below of my front 6-pack manifold.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: auto leveling 12 volt air compressor?

Reply #13 –
Quote from: dans96u295ft –
Does it use the 12 volt compressor to stay level and how much battery will it use,
On my active air system - once I am on Auto Level at my campsite, the compressor will turn on, once or twice per night to re-level my coach. So it does use the compressor to level the coach on my system and it does draw 12V power.

How much power? I am not sure, my coach is an all electric coach and everything runs off inverter when I dry camping with no shore power. Every morning I run the generator for a few hours to top off the batteries - but to answer your question "yes" the batteries run the 12 volt compressor. 
 

Re: auto leveling 12 volt air compressor?

Reply #14 –
The reason the level system switches to the aux compressor from the air dump is because you have air brakes. At 60 lbs the spring brakes activate. So if you have to leave your position in an emergency you don't have to air up. You still have 80 lbs. Your coach has leveled UP keeping you off the tires. If it leveled down continuously until all air was gone, you would have to wait for it to air up to move because the brake would have activated. Both of my air tank gauge needles go up and down together. This is of course in a perfect world, out of the factory, brand new with no leaks.
1994 U280, Build 4490
Deming, NM.