The tech removed the fuse to my 12 volt hwh air compressor. I can't find it and can't find it in the schematics.
How many Amps?
One of them is a 5 amp fuse probably that would be the one.
Control wiring is 5 amp fuse. The 1/3 HP compressor is 28 amps. The circuit breaker should be about 35 amps.
I tried a fuse, but the compressor runs continuously. Now I know why the fuse was removed.
As best I can figure there are three ways for the compressor to come on.
1. Make sure the dash switch is off, that opens the air line solenoid to the wet tank, lowers pressure and starts the compressor
2. If the pressure switch is below the start point then it sends a 12v signal to the essex relay to start the compressor.
3. If the HWH system sends a 12v control signal to the essex relay the compressor will start.
Any of these will start the compressor and actuate the 12v NO solenoid on the water trap. If it is hot then one of them is calling for air.
Removing the fuse disables the switch and solenoid to the wet tank and power to the pressure switch.
If it still comes on them test for 12v at the trigger side of the essex relay. If it has 12v then the HWH system is calling for air.
If the fuse is in and it is not the HWH system then the pressure switch is closed, the essex relay trigger has +12v and the compressor runs. The switch could be bad, the compressor may not be compressing or you have a significant leak. If it is not leveling the coach the compressor is filling the HWH tank which provides pressure to the seal manifolds. The tank pressurizes to about 90 psi. The slide seals are regulated to about 12 psi.
To completely disable the compressor and not let the water trap solenoid stay hot, move and merge the HWH control wire and diode (you might have to add a new diode) to the wire from the pressure switch and add an on/off switch between that junction and the trigger side of the essex relay. Doing so means nothing can energize the essex relay and therefore the compressor and since 12v does not get to the essex relay trigger the water trap solenoid is not energized.
^ Pulling this out to emphasize it ^
If you cannot get the aux compressor to stop running unless you pull the inline fuse, you have an issue that needs attention.
The primary causes we have seen are a leak in the slide bladder system and a leak at the bottom of the clear condensate bowl that has the NO solenoid on it (or debris on the seat of the NO solenoid plunger), hindering or preventing build-up of pressure.
It is fairly easy to add a 90° turn valve to the bladders to isolate them and a pressure gauge to monitor pressure in them. And add a pressure gauge to the HWH tank too. When the compressor is off and the water trap solenoid is open there is no pressure from the check valve by the pressure switch back to the compressor. All of this assumes your system is original, not modified and functioning. Later models (past 2001) had some factory installed valves.
If you lose the compressor or have no pressure in the HWH tank you cannot deflate the slide bladders. You can add a small vacuum pump plumbed in properly as a backup to deflate the bladders to allow you to get them in. It does nothing to reinflate them.
Tom,
Is it the original Thomas Brand compressor? I had the same issue with the compressor never shutting down. I was confident that I didn't have leakage anywhere so that it never turned off.
I removed the compressor and took the head apart. Sure enough, the plastic seal inside the cylinder was shot. One edge had a tear in it. Even though it sounded normal when running, it was not compressing any air.
They do have a rebuild kit available for a couple of hundred dollars. I just ended up replacing the compressor. No promises, but it may be worth a look.
After I run the compressor for a few seconds and then pull the fuse, I can hear the hiss of air escaping for a second. Sounds like it's coming from the overpressure release valve. I'll been to cut some cable ties to get to it after I get home from this short trip.
Tom it might be the unloader valve bleeding off air which is normal.
Oh! That is a problem.
Mark, the compressor in your coach is the smaller 1/10 hp compressor. In 2002 and later they wend to a significantly bigger 1/3 hp Thomas compressor. Rebuild kist are available for both. I bought a new smaller one for my coach, rebuilt the original one, sold both and bought the bigger Thomas compressor for much more $$.
This one is about 1/2 the price of the bigger Thomas compressor, has a high duty cycle rating, up to 150 psi. Other have used these. It might be worth a try. This source has $50 off and free shipping.
ARB 12V Twin Compressor | CKMTA12|Northridge4x4 (https://www.northridge4x4.com/part/compressors/ckmta12-arb-twin-compressor)
I'm home now, and after cutting some zip ties and spraying the water trap assembly with 409, a mound of bubbles has shown me where the air leak is. Looks to be one of the threaded fittings at the bottom of the clear water trap, leading to the selenoid.
It's a tight fit for my fat fingers. Does the clear bowl come off for easier access? Is one of the fittings screwed directly into the clear bowl?
If it's like mine yes. There is a aluminum fitting in the bottom of the blasting bowl. Subject to corrosion. Hex head inside. The plastic bowls are prone to crack
Scott
It does come off easily, but if you're talking about the condensate bowl, the problem is likely the plastic bowl itself having developed thermal cracks or corrosion of the fittings.
Tutorial with part numbers:
HWH Filters and Bowls (http://www.irvblog.com/foretravel%20projects/HWH-Filters/)
This one may be an alternative to the OEM water trap and solenoid. I used this one in my rebuild. It is a filter and moisture trap, the bottom valve closes under pressure and opens when pressure is reduced and lets the water out. You can attach a drain tube. It needs to go in ahead of the check valve before the pressure switch.
PneumaticPlus SAF3000M-N03BD Compressed Air Particulate Filter 3/8" NPT -... (https://smile.amazon.com/gp/product/B005JDL46W/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
Roger, I would like to copy your setup. Do you have part numbers for the pressure switch by chance ?
Thank you
Not Roger, but looks like a regular Square D pressure switch, pretty sure any big box store will have them
This is the pressure switch I used. I adjusted the upper cutoff pressure from about 90 psi to 95 psi.
I added pressure gauges to the HWH tank, the air bladder and assembly ahead of the pressure switch.
This is the second air filter, 5 micron.
PneumaticPlus PPF2-N02B Miniature Compressed Air Particulate Filter 1/4" NPT... (https://amazon.com/gp/product/B016XIX73O/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
Wilkerson desiccant drier X06-02-000. (Cheapest I have seen them)
Wilkerson X06-02-000 Dryer,Desiccant for sale online (https://www.ebay.com/itm/NEW-Wilkerson-X06-02-000-Dryer-Desiccant-with-Silica-Gel/133502760716?hash=item1f1562770c:g:Ue0AAOSwO~1fRXzb)
Check Valve
Control Devices-M2525-1WA Brass Ball Check Valve, 1/4" NPT Male: Industrial... (https://smile.amazon.com/gp/product/B007GDX93E/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
I have presented this issue on other talks on this forum, but I am going to revisit this on this post to see what answers I get.
I never hear my air compressor (located in the front large bay drivers side, beside the Inverter) come on.
I level my coach, with the 4 red lights on, then I just turn the key off. The red light REMAINS ON bright all the time. Over a couple of days the coach begins to lower (the red light remains on still.....no sleep mode, blink dimly..anything) and the air compressor does not turn on. After a couple of frustrating days of watching this happen, (and yes I may have a leak somewhere..) I start the coach until the air brakes pop off at about 120, then re level. The coach airs up and the saga continues.
Is there a fuse (and where the heck is it located???) for the air compressor that may be blown?
Am I truly missing something here?
I do remember the air compressor coming on and viewed it last summer..
Help!
Peter
Peter,
Your HWH compressor is on a manual reset breaker in the basement. It is hid behind the removable fiberglass panel that is hanging on the basement wall big bay drivers side.. You will find there is a little button that will be popped out, take a pencil and push it back in.
Mike
Hi Mike,
attached are pics of behind the white fiberglass panel drivers side first bay. I do not see any reset breakers for the compressor.
Am I looking in the wrong area?
Peter
Should look like this
well if this it, it is not labeled...
That sure looks like the re-setable breakers to me. Look for one with the little black plastic piece sticking out farther than the rest.
Wonder why yours doesn't have labels.
Year model, day of the week, or bad hair day
From the pic. it looks like the net to the bottom one on the inside may be tripped. The electric print should tell for sure which one is for the HWH.
Mike
WELL...Back to the drawing board.
Went to each individual "little black" button and pushed them in.
None of them were protruding further than the other.
Still nothing...
The HWH compressor is 15 amps. Second from the top on the left. Find your drawing same number as this and confirm.
yes I tried resetting all of them. None of them seemed to be protruding so I just reset them all.
Same issue...bewildering..
Oh and I do not have that schematic.
Peter,
This one is close to your coach
https://www.foreforums.com/index.php?action=media;sa=media;in=4746
Mike
thanks...two totally different schematics. Will try that one mike and hopefully that will work. Just a gentle push is all it takes on the breakers right?
Can you jumper 12v directly to the air compressor to see if it starts ?
Tim Fiedler
Gen-Pro.biz
630 240-9139
I think that is my next step
Maybe your pressure switch is bad. Have you checked to see if it's working?
Not sure how to do that. Can you explain please?
Peter
Should be two wires leading into the actual pump ( on mine red and black) if no disconnects, cut wires and begin by adding crimp on disconnects so the pump is easily removed in future if needed, while you have bare ended wires, take jumper cables from a car battery and put the red to the positive jumper and black to negative jumper ( I use short jumper wires with alligator clips on each end). If pump starts, your issue is wiring related. If it doesn't start it likely is a bad motor or frozen piston in the pump.
Tim Fiedler
Gen-Pro.biz
630 240-9139
Travelin man
Can you explain how to check if the pressure switch is working?
Take the cover off and see if the contact points are open or closed. If they're open then close them and see if the compressor starts. If they're already closed then you have a different problem such as wiring, fuse, switch, etc.
Use something like a small screwdriver to push the contacts together (one is fixed and one moves) and also to open them afterwards.
There is some useful information here;
9 Common Well Pump Pressure Switch Problems (https://empirepumpinc.com/well-inspections/well-pump-pressure-switch-problems/#:~:text=Basically%2C%20your%20pressure%20switch%20tells%20your%20well%20pump%2C,turns%20off%20when%20the%20maximum%20PSI%20is%20reached)
Man oh man this confuses me. My compressor is mounted on the same rack as my inverts attached to the roof of my bay. What component do I have to take apart to look at the contacts? I am going to guess this is going to be a major project as I will have Carefully remove the compressor( in very tight space) to get to that.
Peter, mine is a squarish box with a grayish cover. Loosen the nut and pull the cover off. You will see the contacts, mine would stick. I left the compressor on the shelf in my coach and moved all the rest of the parts to the side wall of the bay so they were more accessible.
I am going to start with changing the pressure switch(3) in the HWH. First of besides the Stewart Warner brand is there another I can but on Amazon that is just as good and perhaps cheaper....and will ship to a Canadian address?
The other, perhaps more important question is.... is there anything I have to do special besides unscrewing the pressure switch and re attaching the two wires? Do I have to dump the air, turn off the salesman switch, etc before doing this replacement?
Like I mentioned I am going to start thee as the HWH service manuals kinda says things revolve around the pressure switches. If that Does not do the trick I. Getting my compressor working I may try the pressure switch on the actual compressor. The other factoring thing is there is very little room to work on the compressor as it is located on the same rack as the inverter on the bay ceiling