RVAC Central Air Conditioner

Topic: RVAC Central Air Conditioner (Read 3971 times) previous topic - next topic

RVAC Central Air Conditioner

August 29, 2018, 12:31:21 pm

Our AC decided to go on the fritz the other day and while we were looking through our paperwork we discovered through letters that our coach was actually Mr. Fores show coach that he used to take to shows to demonstrate the central air (basement) system which was rigged to run off a second engine AC compressor and get power from a 1500 watt inverter to run the fans. Pretty cool right? Well we thought so until we discovered that our circuit board is melted and that there are no replacements to be found anywhere. The unit is a RVAC model 2702 which was used on a number of Prevost and Newell coaches. We don't much care about the engine compressor system working as it's not hooked-up but it was over 95 in the coach during the day and with 2 animals we have to have a functioning AC. Does anyone know where we could locate one of these circuit boards? The circuit board part #is 52017 according to the service manual. I have contacted Newell since they are just up the road and was told that they sold the last one they had within the past week (my luck) but that they were in the process of having new circuit boards built so the can continue to service their customers and that they would contact us when the got them in. I have not tried Prevost yet but may call them too. We will probably try to find a used portable ac unit to get us by for the time being if there are no other options.

Re: RVAC Central Air Conditioner

Reply #1 – August 29, 2018, 01:11:52 pm

Sorry to hear about your problem. Sounds like you are on the right path to get a replacement. There are AC units on the market that can be placed outside the space to be cooled and have ducts that move the air in and out. Not likely to be very efficient though for distributing the air. You might be able to rent one. We used to have shops that repaired TV's and radios. Some old time ham radio guy might be able to fix your board if it is not too badly fried. Some boards have parts that are difficult to find too.

Re: RVAC Central Air Conditioner

Reply #2 – August 29, 2018, 01:19:01 pm

Did you do a google search for circuit board 52017. I did and found something, but not sure if it is what you are looking for.

Re: RVAC Central Air Conditioner

Reply #3 – August 29, 2018, 03:02:35 pm

Try SCS 817-293-5313,they are in Fort Worth TX.

Re: RVAC Central Air Conditioner

Reply #4 – August 29, 2018, 03:47:33 pm

You might try posting and reading up on the SCS units on Newell Gurus
Quite a few of the guys there have the SCS basement units and have come up with some solutions that might help. The circuit boards are rare but I think someone has or is researching using an Arduino to replace the circuit board.
Some of the components on the board are replaceable but it seems the biggest problem is resolved by adding separate relays to take the current off the board.

Re: RVAC Central Air Conditioner

Reply #5 – August 29, 2018, 04:29:09 pm

My wife tried contacting SCS who was bought by Victory Climate and they told her that they didn't acquire any of the basement unit parts in the merger. I have been searching around but haven't came up with anything too promising yet. We are going to purchase a used portable actually unit this evening that will hopefully get us by for a little while. Hopefully it will start cooling down outside pretty soon. Thanks for all the help guys!

Re: RVAC Central Air Conditioner

Reply #6 – August 29, 2018, 04:40:42 pm

Quote from: The Soft Boulders – August 29, 2018, 12:31:21 pm

...central air (basement) system which was rigged to run off a second engine AC compressor and get power from a 1500 watt inverter to run the fans.

I (and other members) would really like to see some photos of your unique A/C setup, if you ever get it working again. I'm trying to visualize how the cold air gets distributed throughout the coach. This is the first I have ever heard of this system in a GV, but did find a few references to this same coach in a search of old posts. It may be "one of a kind" and as such has a lot of historical value. I know - you don't give a doody about that right now. You just want your A/C working...we desert dwellers sympathize.

I HOPE you can find a way to fix the basement system, and return it to satisfactory service. But if you can't, I'm thinking it would not be hard to convert your coach over to roof A/C. The two mounting points in the roof are already framed in metal, so would just need to cut out the holes. If you installed A/C units with wireless remote control, then all that would be needed would be the 110V power supply wires from the breaker panel. I wouldn't be surprised if the wiring is already up there in the ceiling. Foretravel often leaves wiring in place for unused features, rather than having to make up a custom wiring harness. If you do decide to go that route, I would recommend having the conversion done at the factory, where they would have all the parts necessary to make it look and work right,

Good luck!

Re: RVAC Central Air Conditioner

Reply #7 – August 29, 2018, 04:51:52 pm

It may be possible to have your board rebuilt since it's an older type with individual relays, etc. Worth looking for someone that does that.

Re: RVAC Central Air Conditioner

Reply #8 – August 29, 2018, 04:58:48 pm

Before I bought my Foretravel I did look at a few Newel Coach's and at that time they had an active forum, and I remember the basement air control board coming up for conversation a few times. Possible you could do a search there or someone there may be able to steer you in a direction.

Re: RVAC Central Air Conditioner

Reply #9 – August 29, 2018, 05:15:41 pm

I can't get mad about it although I do laugh at myself for our complete naivete when it comes to the coach. We love this baby but might just have bitten off more than we can chew. There is some excellent information on the Newell guru site about rebuilding the board and adding some external relays but that is beyond my abilities. If I get the board out I may send it off or see if someone around here can fix it if it's not completely toast. As to the rarity of the system the people at Foretravel had no idea it existed haha!

Re: RVAC Central Air Conditioner

Reply #10 – August 29, 2018, 05:28:49 pm

The ducting runs through the cabinet by the couch and T's at the ceiling running back to the bedroom and is vented through the overhead storage.

Re: RVAC Central Air Conditioner

Reply #11 – August 29, 2018, 05:34:45 pm

That is really interesting the way they routed those air ducts. How well did it work, when it was working? I assume it only works when the engine is running? But then what happens when you are parked at night? I guess there is a fan somewhere in the system to circulate the air. Does the control panel look like a automotive dash A/C control? So many questions...

I'm wondering what is your coach build number. Look on the metal plate next to the driver seat. In the Model No. at the bottom of the plate, your build number is the 4th,5th,6th and 7th digits. On our data plate (below) our build number is 4359. Just curious how close together our coaches were on the assembly line.

Re: RVAC Central Air Conditioner

Reply #12 – August 29, 2018, 05:46:28 pm

The ac works off of shore power as well and has two 20A breakers (one for each compressor) in the panel under the bed. The system worked really well and kept the whole coach evenly cool.

Re: RVAC Central Air Conditioner

Reply #13 – August 29, 2018, 05:48:07 pm

Thanks for telling me that, i was wondering what it was as well. Our build number is 4196. Sorry for the poor quality photos my phone camera is all busted.

Re: RVAC Central Air Conditioner

Reply #14 – August 29, 2018, 06:04:11 pm

Quote from: The Soft Boulders – August 29, 2018, 04:29:09 pm

My wife tried contacting SCS who was bought by Victory Climate and they told her that they didn't acquire any of the basement unit parts in the merger. I have been searching around but haven't came up with anything too promising yet. We are going to purchase a used portable actually unit this evening that will hopefully get us by for a little while. Hopefully it will start cooling down outside pretty soon. Thanks for all the help guys!

TOAST!

Re: RVAC Central Air Conditioner

Reply #15 – August 29, 2018, 06:12:37 pm

Here are some of the documents for the system (in .jpeg this time). The RVAC system is a dual compressor with a breaker for each one, there is also 2 compressors on the engine, one I assume, runs the dash ac and the other runs the RVAC.

Re: RVAC Central Air Conditioner

Reply #16 – August 29, 2018, 06:13:44 pm

Thanks for all the interesting info. I'll leave you alone now, cuz it's getting on supper time. But please keep us informed about how it goes getting the system (hopefully) repaired. I'm thinking the Newell people might be a big help. We have had dealings with their members before, and they are a good bunch. Lots of systems in common between older Newell and Foretravel coaches.

Re: RVAC Central Air Conditioner

Reply #17 – August 29, 2018, 10:28:59 pm

I'm still poking around the Net, looking for info on this interesting basement A/C equipped U280. Found the following document, which describes what sounds to be pretty close to the system installed in this unique coach. The diagram doesn't look at all like what I was picturing in my head. Looks much more "modular", which makes sense if it was adaptable to different make/model coaches.

https://prevostcommunity.com/PDF/Model%202702.PDF

Re: RVAC Central Air Conditioner

Reply #18 – August 30, 2018, 03:02:43 am

Sold a half dozen Winnebago's with that system. Do not remember engine driven. Worked well. Cold

Re: RVAC Central Air Conditioner

Reply #19 – August 30, 2018, 09:09:57 am

Quote from: Caflashbob – August 30, 2018, 03:02:43 am

Do not remember engine driven.

Yes - I don't really understand the compressor mounting location either. Hoping Hannah & Tyler will post some photos of the engine compartment, and the rest of the components that are mounted under the coach.

Re: RVAC Central Air Conditioner

Reply #20 – August 30, 2018, 12:10:10 pm

[Found the following document, which describes what sounds to be pretty close to the system installed in this unique coach.]

I'm not sure how to insert a quote, but that is the same manual that we have for our system.

Re: RVAC Central Air Conditioner

Reply #21 – August 30, 2018, 03:09:12 pm

Quote from: The Soft Boulders – August 30, 2018, 12:10:10 pm

I'm not sure how to insert a quote, but that is the same manual that we have for our system.

To "quote" another member's post, just go to the post and click QUOTE in the bottom right corner. This opens a window where you can type your response. It is polite to edit the quoted text, so that it is pared down to only the pertinent lines. This saves bandwidth and makes it easier to read.

Re: RVAC Central Air Conditioner

Reply #22 – August 30, 2018, 03:23:34 pm

So there are two A/C compressors on the engine. Hmmm... The top compressor (the one with the belt) must be the one for your basement A/C. The other one is the standard unit that would (if it was hooked up) provide the dash A/C.

I still don't understand how the system can run off both the engine belt driven compressor and off shore power. The diagram in the manual I linked above shows 2 compressors mounted between the condenser and the evaporator. I assume these are driven by a 110V motor. So if that's correct, then there are actually 3 compressors for the basement air, and it switches between them? Very complicated...

Re: RVAC Central Air Conditioner

Reply #23 – August 30, 2018, 03:58:06 pm

On my 1998 Newell with the SCS A/C I had 2 separate systems. Each had 2 compressors which was controlled by the hi/lo switch. On low only 1 compressor would run, helpful if only 30amp or lower hookups. Each compressor was on a different leg of the 50amp. On high if the temp difference was more than a couple degrees between set and inside temp then the 2nd compressor would come on. So your system may have 2 120vac compressors like mine had, but also has a separate compressor run by the engine. It sounds like your system also used the inverter to run the blower fans on the evaporator and condenser when using the engine compressor.
On the newellsgurus.com site we've been able to source out all parts with the exception of the circuit boards. Some of the guys there have come up with a great solution that uses relays to get the current off of the boards. Pretty easy upgrade and should keep the boards working for a long time. BTW the boards have replaceable components, so if you're good with a soldering iron you might be able to rebuild it.
I really liked the SCS, it cooled great and was very quiet compared to rooftop airs and being a single package it was easy to slide out to work on.

Re: RVAC Central Air Conditioner

Reply #24 – August 30, 2018, 03:59:21 pm

Quote from: Chuck & Jeannie – August 30, 2018, 09:09:57 am

Yes - I don't really understand the compressor mounting location either. Hoping Hannah & Tyler will post some photos of the engine compartment, and the rest of the components that are mounted under the coach.

Is it possible a eng run compressor and evaporator in parallel with the electrical ac evaporator ? I am thinking that to switch engine compressor piping to electric compressor piping, would be a nightmare.
Three separate systems, dash, electric and second engine compressor etc with electric blower forcing air over engine driven compressor and evaporator through house duct system?

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