Air Compressor

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Air Compressor

September 03, 2013, 09:43:05 am

When using the air compressor do you have to turn the generator, or engine on for power? I had connected the compressor through it's electric plug to shore power (my house) when using the compressor and it blew the breaker, (which was not 30 or 50 - probably 15 or 20). So, I am trying to understand it's requirements. I cannot read anything on it. It's original I think, on my 1990 U280.

Susan

Re: Air Compressor

Reply #1 – September 03, 2013, 10:37:07 am

Susan,

The small compressor used to level the coach is 12V and should not be blowing a breaker and in fact, should not have a plug on it that would allow you to plug into 120VAC. The big compressor is driven directly or with belts from the main engine.

Perhaps you have another compressor on board that was installed by a previous owner. Please give details on the location of the compressor and what you are trying to use it for.

Pierce

Re: Air Compressor

Reply #2 – September 03, 2013, 11:02:22 am

My 97 blew a fuse also recently. I wonder what size is supposed to be inline?

Mechanic buddy says there is a rebuild kit for the motor if needed.

Bob

Re: Air Compressor

Reply #3 – September 03, 2013, 11:25:20 am

Pierce,

This compressor is located under the steps in the bay. I thought it had always been there, but I took photos just now and it does look installed by someone other than Foretravel. There seems to be a built plywood bench it sits on.

I was filling air into the small tires of a hand dolly/hand cart.

Susan

So, where is the compressor that fills the airbags, pulls up the step, etc.? Is it near the engine?

Re: Air Compressor

Reply #4 – September 03, 2013, 11:43:53 am

Susan, the confusing advice above is because FT was using 115 volt AC compressors in 1990, but the later coaches changed to 12 volt. I don't know when the changeover occurred, but 1990 was definitely 115 volt as you picture. It was standard. My 1990 had similar trouble when using a 15 amp circuit and a long extension cord.

Your solution should be to try a heavier and/or shorter cord...or a 20 amp house circuit. My compressor would make noises and try to start when it couldn't get enough current.

Your generator would provide more than 15 amps...but a better house current supply is the answer.

Re: Air Compressor

Reply #5 – September 03, 2013, 11:46:13 am

So, Dave, should I start the generator on the Foretravel and then plug the compressor into the coach plug to run the compressor?

And I know this is very basic, but how did you determine or see the 14 amps?

Susan

Re: Air Compressor

Reply #6 – September 03, 2013, 11:50:38 am

That is a very serious little compressor. Would think you would need to either start your big generator or have a big heavy duty cord leading out from a good plug close by. Long runs and small cords delay the startup, lower the voltage while running heating the motor and pop breakers. Dave has it quite correct.

Can't really see what kind of compressor it is in the photo but some require an unloader valve so they don't have to start up against tank pressure. Check your compressor model online to see if one is required. I have a one on my shop compressor that occasionally sticks. Pops a breaker when it does.

Pierce

Re: Air Compressor

Reply #7 – September 03, 2013, 11:52:00 am

Quote from: Susan – September 03, 2013, 11:46:13 am

And I know this is very basic, but how did you determine or see the 14 amps?

Susan

It is in your picture. The lower line that says 14.0/7.0....means it takes 14A at 115V or 7A if wired as a 230v motor.

Re: Air Compressor

Reply #8 – September 03, 2013, 11:56:51 am

Quote from: Dave M – September 03, 2013, 11:52:41 am

Susan,
Either use a heavier outlet with a heavier cable or yes start the generator, on the other hand you could use the air supply on the coach if it is setup with a hose for tires etc.

Dave: If you will look in her pictures, you will see the coach's hose for the tire-fill comes off of this compressor. Exactly as was my 1990 U280...but nothing like my 2002 U270.

Re: Air Compressor

Reply #9 – September 03, 2013, 11:58:47 am

Okay, Brad, I couldn't see down that far. Now I see it. Thanks.

Re: Air Compressor

Reply #10 – September 03, 2013, 12:00:28 pm

Quote from: Brad & Christine Slaughter – September 03, 2013, 11:56:51 am

Dave: If you will look in her pictures, you will see the coach's hose for the tire-fill comes off of this compressor. Exactly as was my 1990 U280...but nothing like my 2002 U270.

So, Brad, do all 1990's have a little compressor in the basement? Only mine may have been replaced?

Re: Air Compressor

Reply #11 – September 03, 2013, 12:10:23 pm

Quote from: Susan – September 03, 2013, 12:00:28 pm

So, Brad, do all 1990's have a little compressor in the basement? Only mine may have been replaced?

I haven't seen all of them, but what you have is EXACTLY the same as what I had in my 1990 U280.

Re: Air Compressor

Reply #12 – September 03, 2013, 12:15:08 pm

...and I was recently told that my old coach is owned by folks in Kansas, so it isn't the same coach...LOL.

Re: Air Compressor

Reply #13 – September 03, 2013, 12:26:04 pm

Susan,

You should have a plug in the compartment not far away from the compressor. Start the generator and then plug in the compressor. Shore power from a 30 or 50 amp RV connection should also do it. A long 120V extension cord into the Foretravel plug via an adapter won't do it. I have a small contractor's compressor on board so have been through the generic extension cord route and the "I think I can, I think I can" start up attempt.

Pierce

Re: Air Compressor

Reply #14 – September 03, 2013, 12:45:26 pm

Thanks, everyone! I so appreciate this forum.

Susan

Re: Air Compressor

Reply #15 – September 03, 2013, 11:06:18 pm

That's the same compressor that is on my '91. I think that was the last year for them because in '92 they changed to the HWH system. These were standard on the U280/U300 coaches and are needed to keep the air bags up when parked. You know how much air you're leaking by how often you hear it run. Mine used to run once every 2 days, now it's every day. There is no unloader on it, only a check valve. Never seems to be a problem starting. I think the compressor side of the check valve will always bleed down before the system ever calls for the compressor to come on again.

There's a standard (shop style) pressure switch that turns on the compressor at about 75 psi and off again at about 95 psi. I have my compressor going through a plug in timer so the compressor doesn't go off in the middle of the night and wake me up. It's an heavy duty rated (15 amp) timer and digital so it never looses it's clock setting when power is interrupted.
My notes show the model is 5HCD-010M500X made by Gast. The label shown in the photo is of the motor only. I put in a rebuild kit on '07. Here's the manual.

P.S. Any easy way to turn the compressor off is with the dedicated circuit breaker under the bed. The plug next to the compressor in the basement is rather troublesome to reach. On another note, if for any reason (clogged dryer, failed engine compressor) you loose air while driving, remember to turn on the generator and this compressor might be enough to keep you going or at least get off the road to a safe place.

Re: Air Compressor

Reply #16 – September 06, 2013, 12:38:58 pm

Quote from: JohnFitz – September 03, 2013, 11:06:18 pm

That's the same compressor that is on my '91. I think that was the last year for them because in '92 they changed to the HWH system. These were standard on the U280/U300 coaches and are needed to keep the air bags up when parked. You know how much air you're leaking by how often you hear it run. Mine used to run once every 2 days, now it's every day. There is no unloader on it, only a check valve. Never seems to be a problem starting. I think the compressor side of the check valve will always bleed down before the system ever calls for the compressor to come on again.

There's a standard (shop style) pressure switch that turns on the compressor at about 75 psi and off again at about 95 psi. I have my compressor going through a plug in timer so the compressor doesn't go off in the middle of the night and wake me up. It's an heavy duty rated (15 amp) timer and digital so it never looses it's clock setting when power is interrupted.
My notes show the model is 5HCD-010M500X made by Gast. The label shown in the photo is of the motor only. I put in a rebuild kit on '07. Here's the manual.

P.S. Any easy way to turn the compressor off is with the dedicated circuit breaker under the bed. The plug next to the compressor in the basement is rather troublesome to reach. On another note, if for any reason (clogged dryer, failed engine compressor) you loose air while driving, remember to turn on the generator and this compressor might be enough to keep you going or at least get off the road to a safe place.

John,

thank you for this post. I am keeping this whole stream of posts and printing for my file, as I don't pretend to understand half of it...

From your post you say that this is the compressor that keeps the air bags up. Mine never comes on. I wonder if there is some switch or something that has been disabled. My air bags fill when I start the engine and let it run for a minute or so. At that point I notice the coach comes up off of its tires and the step at the door closes. Yesterday after reading your post I started up the engine, waited for the pressure to build and the step closed up, but I stood by the open bay door and listened for this compressor to run but I never heard it come on. That is what has made me think that there must be a compressor somewhere else - like near the engine that operates the air bags and step. A mystery I continue to parse.

I just reread your post. I will try to locate the circuit breaker of which you write, that is under bed. Perhaps mine is shut off?

And thank you for sending the attachment on the compressor.

Susan

Re: Air Compressor

Reply #17 – September 06, 2013, 02:54:05 pm

Quote from: Susan – September 06, 2013, 12:38:58 pm

From your post you say that this is the compressor that keeps the air bags up. Mine never comes on. I wonder if there is some switch or something that has been disabled. My air bags fill when I start the engine and let it run for a minute or so. At that point I notice the coach comes up off of its tires and the step at the door closes. Yesterday after reading your post I started up the engine, waited for the pressure to build and the step closed up, but I stood by the open bay door and listened for this compressor to run but I never heard it come on. That is what has made me think that there must be a compressor somewhere else - like near the engine that operates the air bags and step. A mystery I continue to parse.

I just reread your post. I will try to locate the circuit breaker of which you write, that is under bed. Perhaps mine is shut off?

And thank you for sending the attachment on the compressor.

Susan

Susan, this is your auxilliary compressor. The engine drives a compressor that manages both your air brakes and your leveling (airbag) system. Since it isn't practical to always run the engine, this compressor is designed to keep the leveling system supplied with needed air. Of course, the coach must be plugged in or the generator running to supply the 115 volts needed to run it. And even then, it will not come on unless your air system tells it to. On my 1990, it might come on briefly once or twice at night. So even listening all day long, you may not ever hear it come on. Since you started this thread noting that it was tripping a circuit breaker, it must be functioning?

Re: Air Compressor

Reply #18 – September 06, 2013, 03:01:23 pm

One more thing...I believe the air step is a separate circuit from the leveling system and is fed off of the same tanks as the air brakes (not 100% positive on your coach). When my coach has been sitting and its air pressure has depleted (as indicated by the dash air guages), the step won't come up until the engine is turned on and the pressure gets restored up to 30 PSI or somewhere around there. (I do have a switch to fill the tanks from my auxilliary 12 volt compressor, but that is a 2002 addition FT made, and doesn't pertain to a 1990 model.)

Re: Air Compressor

Reply #19 – September 06, 2013, 03:04:42 pm

Quote from: Brad & Christine Slaughter – September 06, 2013, 03:01:23 pm

One more thing...I believe the air step is a separate circuit from the leveling system and is fed off of the same tanks as the air brakes (not 100% positive on your coach). When my coach has been sitting and its air pressure has depleted (as indicated by the dash air guages), the step won't come up until the engine is turned on and the pressure gets restored up to 30 PSI or somewhere around there. (I do have a switch to fill the tanks from my auxilliary 12 volt compressor, but that is a 2002 addition FT made, and doesn't pertain to a 1990 model.)

Thanks, Brad. So, where on the dash do I see air gauges for the leveling?

Re: Air Compressor

Reply #20 – September 06, 2013, 06:43:03 pm

Quote from: Susan – September 06, 2013, 03:04:42 pm

Thanks, Brad. So, where on the dash do I see air gauges for the leveling?

You don't. There are no guages for the leveling system. Use the 3 levers on the floor to make yourself level with the bubble guage, but there is no separate pressure indicator.

The guages on your dash are for your Air Brake (and air step) system. There was only one on my 1990...upper right in the picture below, near the turn signal indicator, but there are two on my 2002 (front and rear tanks).

Since I dug up my old pictures, I added pictures of the level system and the compressor from my old coach.

Re: Air Compressor

Reply #21 – September 06, 2013, 10:39:57 pm

Quote from: Susan – September 06, 2013, 12:38:58 pm

John,

thank you for this post. I am keeping this whole stream of posts and printing for my file, as I don't pretend to understand half of it...

From your post you say that this is the compressor that keeps the air bags up. Mine never comes on. I wonder if there is some switch or something that has been disabled. My air bags fill when I start the engine and let it run for a minute or so. At that point I notice the coach comes up off of its tires and the step at the door closes. Yesterday after reading your post I started up the engine, waited for the pressure to build and the step closed up, but I stood by the open bay door and listened for this compressor to run but I never heard it come on. That is what has made me think that there must be a compressor somewhere else - like near the engine that operates the air bags and step. A mystery I continue to parse.

I just reread your post. I will try to locate the circuit breaker of which you write, that is under bed. Perhaps mine is shut off?

And thank you for sending the attachment on the compressor.

Susan

Susan,
Yes, it sounds like the compressor is not working for some reason. This compressor should run independently of the engine. You should hear it run when parked and plugged into power or on the generator. I would verify the breaker under the bed is on, then check the outlet in the basement where the compressor is plugged into for power using a nightlight or something similar. It's also worthwhile to look for any red button on the compressor motor. If you see one push in on it to reset it. I looked on mine and I don't have one but maybe yours does. The next thing I would suspect is the pressure switch - that gets more involved.
Other than the circuit breaker, there is no other switch to the compressor that I know of.
I know on my coach the dash gauge does reflect the pressure of the air bag system. From this gauge I see the compressor go on at 75psi and off at about 95psi. Sometimes If I want the compressor to go on, I'll press the brake pedal repeatedly until the pressure drop to 75 psi.
By the way, I love the photo you have for your avatar.

Re: Air Compressor

Reply #22 – September 06, 2013, 10:45:54 pm

Susan - is your map pin accurate that you're in Washington state? Wondering if there are any reasonably-close-by members who might be able to help.

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