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.
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.
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.
Try SCS 817-293-5313,they are in Fort Worth TX.
You might try posting and reading up on the SCS units on Newell Gurus (http://www.newellgurus.com)
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.
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!
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!
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.
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.
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!
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.
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.
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.
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.
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.
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.
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
Sold a half dozen Winnebago's with that system. Do not remember engine driven. Worked well. Cold
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.
[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.
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.
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...
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.
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?
I would like to be more helpful with shedding some light on how it all it works, but I think you guys already know more than I do HA! The complication of it all could be the reason why there is only one like it, probably sounded better in theory than in practice.
So on your Newell setup, I can understand how it would all work on shore power. What about when you were driving down the road? Did you have to run your generator to have any A/C when driving, or did you also have a "automotive" dash A/C system with a engine driven compressor?
I personally don't have any problem with running generator to power the A/C units. That's what we do now. And I can see some advantages to the basement mounting, such as less aero drag from roof projections, and less noise/vibration because you are not sitting directly under the A/C compressor and fan motors.
In the case of the OP's U280, trying to use a 2nd belt driven compressor, and inverter driven fan motors, seems to add a lot of complexity for little gain. Unless the alternator was sized up big enough to cover the battery drawdown, you are just draining your house batteries for no real benefit. Much simpler to run the generator and power the 110V compressor motors directly.
That circuit board looks bad, but I doubt theres much to it besides some relays. Flight systems can probably repair ir for you. They have fixed all sorts of boards for me.
http://m.flightsystems.com
Of course this requires you removing it, getting it to them and repairing the wires to hook it up if they can fix it. Might be easier to cut a hole in the roof and go conventional AC or just replace a roof vent with a rooftop AC.
Appears from his first letter, both engine driven compressors were used for over the road air, but as mentioned, did not work out.
As far as I know Newell's have electric basement or roof airs and separate engine driven compressor dash air.
We're sorry you guys are having such a rough time with your coach. It is not unusual for new owners to make unpleasant discoveries about their newly acquired dream boat. It is why we tell people who come here looking for advice, that they should be prepared for irritating, and sometimes very expensive, problems to crop up. It is just the nature of these vehicles.
Fixing a standard "broken" air conditioner would be so simple. Pull the old one off, drop a new one in. Boom - you're done. Costs some money, but at least you have cold air again and can get on with your journey.
In your case, of course, not so simple. Which puts you guys in a bad spot, and not a lot we can do about it. We really like to help new owners get past their problems, because we know the end result is worth it. If anyone on the Forum can think of any way to help you, you can be sure they will speak up. For now, all we can do is try to understand how your unusual coach functions. We've got some smart people here, and you can bet they are scratching their heads trying to figure a way to help you.
You said Newell is having some new circuit boards made up. Did they say how long until they might be available?
Got the circuit board out, there are no holes burned through it but there is significant damage to some of the components. It burned the AC (alternating current) leg 1 pretty bad and all of the thermostat wires. The circuit leg that goes from the board to compressor 1 is also burned in half.
We will contact them and see what they can do. Thank you
Thats so severe that I doubt it was a bad connection but more likely a short circuit of soem component. You probably need everything checked before possibly burning up a new board.
They said that their engineers were working on having some new ones made up and that they should be getting one of the first ones in fairly soon but that they didn't know when for sure and that they didn't know what one was going to cost.
We were planning on having the unit removed and completely serviced before it was fired back up if we were able to come up with a solution to the problem. There is no telling how long it has been since it has been cleaned because there is no way to open it up without removing all of the duct work on top of the unit.
Seems to me the unit takes 120 volts via a relay or two to power the A/C, and that with your emergency all could be bypassed and that you could manually turn on the system and be cool. Having a wiring diagram could make it easier. Not sure what the circuit board does other than turning off & on based on thermostat and sequencing fan first, compressor moment later.
Thats what it seems like but without seeing the whole schematic I dont know if it uses multiple cooling loops for the engine driven and AC powered compressors or solenoid valves. Just hooking stuff up could be risky without understanding the whole system and how it functions.
Emailed Flight services a picture of the board, they said the damage was to severe for the possibility of repair. Neither of us really want to do away with the system and replace it with roof units, so the search for a new board continues!
I think you should re-examine the reason you bought the coach.
If you plan on restoring it to like new condition like somebody would for a collector car, go for trying to repair the system with a money is no object philosophy. Problem is, hardly anybody but you will appreciate your effort. It is a one of a kind engineering experiment that Foretravel did. Interesting when new, but now the coach is 25+ years older. What about all the other components in the A/C system. Your system is more complicated than a home central air system, how many of those last 25 years?
If you bought the coach to enjoy, put the novelty of the system out of your mind and move on. Pull the unit and install a couple roof airs, and enjoy your new purchase.
If you bought a Newell or a Prevost you would have a full support system to help you, you didn't, and there is nobody that can help, your on your own.
People will attempt to help you but, its a money pit.
How are the other systems on the coach?
With an older RV you may have other issues to address that may require money and time that you may not want to allocate to the one off cooling system.
I wish you the best.
I would join the Newellguru forum and post your problem. Newell used the SCS systems for several years and there are people on that forum that are very knowledgeable on SCS repairs.
That circuit board is mainly an relay switching board and if you are unable to find an replacement I believe you have enough info in that I believe you can rebuild it. I had the same problem with my dash air, one year only, no replacement, no company would look at it and no one had an diagram, least you have one. Link below is what I was up against and without a diagram I got it fix, just a couple relays and a few diodes is all it needed.
Javelina A/C Logic Controller (http://www.foreforums.com/index.php?topic=30367.msg265402#msg265402)
I found quite a few threads about the SCS basement A/C system over at a forum called luxurycoachlifestyle.com. Thread linked below is typical, and has several posts by a member named "RussWhite". He sounds like a expert on fixing/rebuilding the circuit boards. I think he may also be a member at the NewellGurus forum. If there was some way to get in contact with him, he might be of help in getting your burned up circuit board either repaired, or replaced.
Looking for Newell Coach Basement Air Conditioning Replacement - Luxury... (http://www.luxurycoachlifestyle.com/forums/showthread.php?t=4955)
X2
In 2002, we toured the Newell factory, twice, and we spent a lot of time understanding the detailed differences between a Newell and Foretravel. We "had the itch" and we were seriously looking at options with a hard budget figure in mind. We didn't know what we know today, but we were surprised when three of the Newell staff (sales, service and Engineering) all separately said wait for a used Newell that had IFS and one that did not have the belly (SCS, I assume) AC. Newell had done several conversions to remove the SCS and install roof airs, even then. At that time, the factory conversion was in excess of $6K each unit, and of course was not as clean as a coach initially designed with roof airs.
Even then, basement capacity was of great importance to us and it is even more so today as fulltimers. AC's in the basement and duct work internal to cabinets and in the overhead uses up fulltimers storage space that isn't easily recovered. We didn't appreciate all of that then but we sure do now.
Since that long ago surprise at the factory, I have worked on two Newell's with AC problems and I was further surprised. Both problems required complete removal of the basement AC units to repair. On one, the two AC's were separated units, one fore and one aft in the basement. They had to be completely removed to repair/replace compressors, flex tubing and to be recharged. IIRC, the factory estimate was north of $8K (ea.) for a local authorized dealer to remove, repair, recharge and reinstall, with shipping to and from Miami, OK on each end. Even factory remove and reinstall had an on-site nine-man-hour turnaround time (ea AC). At that time, It was less expensive for the owner to solicit help, to buy two new units and to replace them. It was a miserable, tight job and it took three of us amateurs four plus days to do it. It definitely would have been easier to install two or three rooftop units with remote controls.
I now see little "up-side" to basement AC's, other than someone trying to maintain original design for authenticity's sake. The basement ones I have had experience with are very quiet as compared to roof airs. But everything else is downhill. (serious loss of storage space, long duct runs that compromise cooling effectiveness, not nearly as effective in cooling the coach on a hot day as ducted air in the ceiling, much more difficult maintenance, more complex control systems, flex components that are prone to breaking when trays are extended as well as components that don't age well in highly elevated temperature spaces, even recharges require complete removal on the basement AC's that I have worked on, etc.).
I think Foretravel dabbled with it, in a test bed, but perhaps experienced some of these deficits and the design didn't make it to production. If it were mine, if I were restoring to collector status and money was no object, then I'd go for authenticity. Otherwise, I'd follow the Newell suggestion in 2002 and move to a roof air solution.
Our 42' FT, with three ducted roof airs, that are now 17 years old, had no trouble maintaining 74 degrees inside, all of this summer, always using only two of the three AC's at a time, with outside temperatures frequently above 110 degrees and occasionally above 120 degrees. The Newell that we worked on was a dark colored coach but, at high temperatures, it had trouble getting the coach more than ten degrees below outside temps.....e.g. - inside below eighty degrees when the outside temps exceeded ninety degrees.
Just my take. Sorry you are having these troubles and I wish you all of the best in finding a speedy, good solution.
HTH,
Neal
hi, i own and operate the newellgurus forum and was contacted by one of your forum members about this thread. folivier is a dear friend and has a foretravel now and has had two newells previously and his advise is spot on.
russ white is a member of gurus and the folks on there have been through all of this about the scs basement airs. my 02 newell has 2 basement scs systems each with two compressors. my control boards were redone with new relays preventatively. i also carry a spare. on newellgurus there was a member selling an scs control board a few months ago so you might do a search under parts for sale for scs control board. i can take an entire basement air out of the bay in less than an hour. then the basic things inside are standard compressors fans, etc. any aircon guy can work on them. the biggest pain is that they were originally closed systems so fill ports need to be added. again, any aircon guy can do that easily.
once 4 slide newells became common, they went to 4 roof airs. another thing i take with a grain of salt is how cold folks say they can get their coach. i live in the phoenix area. i assure you in july, you will not get it as cold inside as you would in denver....ha
the way scs did those boards is silly. all the 120v power flows through the boards. so there has been two stages of fixes with our folks. the first it to put better connectors on as one of the failure points is the connections. the second stage is to use external power relays to take the extreme power load off of the board. a fairly simple task and is fully documented on my forum.
previously newell would only sell a board if you had one to trade in since they were just getting them rebuilt. i agree with the folks who looked at your board in that some of the traces on the board are very likely compromised.
i believe newell is now doing a completely new board.
one of our members also has duplicated the board with a breadboard programmed with a microcontroller. but he is just playing with it and it is not ready for others to do. you also have to be pretty handy....putting it mildly
as for the cause of your board getting toasted, it is likely one of 3 things.....1st....a short somewhere in the circuit anywhere between the control board and inside the unit. it could manifest it self at the weakest link which is the board. the board/relay acted like a fuse and blew....
2nd...a loose solder joint causing a short doing the same thing as above. like i said, all 12 amps or so for each compressor is flowing through those wires and the board and associated relay
3rd. a failure of the power relay.
like someone has said, you want to make sure you dont toast another board.
several newell folks have added roof airs and are happy with them. some have them ducted and some just have them just blowing from the grill. wiring can be easily added by using conduit on the roof and running to each aircon and then to a chase near your 120v breaker panel. the basement airs work pretty well. my only critique is they are pretty noisey.
my gang is very helpful and feel free to go over there and ask questions.
thanks as always for the warm welcome you guys have given me.
tom
Newell Tom is a great guy and has worked our Forum providing HWH solenoid parts. A good contact for all things Newell. You have come to right place to get your basement aircon working.
The ad Tom mentioned is still there in the Classifieds on their forum. It was posted 04-30-2018. It is for one "professionally reconditioned SCS control board", and the seller is asking $500. Since the boards are basically unobtainable, would certainly be worth checking into!
Don't know if this link will work, unless you are a member of their forum (I am):
SCS control board for sale (http://newellgurus.com/showthread.php?tid=4184)
Thank you to everyone for your comments, we are truly blown away by the amount of time and effort that you guys are willing do donate to help us. Since the summer is almost over and the ac is going to be less vital, I would really like to give it a go at fixing it. It will more than likely be more difficult and less cost effective but I enjoy a challenge and my ego for some reason won't let me take the easier route of installing roof units, at least not until we have extinguished all possible solutions. A couple of years ago I rebuilt the transmission from my samurai on our kitchen table, it definitely wasn't the quickest or most cost effective way to go about it because I had to buy a shop press and various bearing pullers along with the parts plus I had to install it, remove it and disassemble 3 times before it was right but the experience was worth more to me than the extra cost. Perhaps I am just a glutton for punishment (my wife says I thrive on suffering) but the only way for me to learn my lesson is to have the wind kicked out of me a few time. Besides, with such a knowledgeable group of folks who are willing to help there's got to be a solution, even if I have to take it piece by piece.
It works for me. I am not a member (yet)
Buy the board.
Tyler, I owned a commercial HVAC company for years. We serviced transport refrigeration as well. I am (unfortunately) very familiar with overly complicated control circuits.
Basic AC systems are very simple. First, the components have to work; meaning the compressor has to run and compress the refrigerant, the condenser fan (outside) has to run and move air, and the evaporator fan (inside) has to run and move air. The compressor will have capacitor and/or a potential relay that will fail. The fan motor may have one as well. These can and should be checked and replaced if needed. I usually replace them anyway since the get weak with age, are inexpensive, and will fail at the most inopportune time.
Next you need a control circuit. The simple circuit is a contactor (relay) to actually connect 120V to the components upon demand, and a thermostat to control to contactor. Typically, the compressor and the condenser fan are controlled by one contactor and the evaporator fan by a second one. This allows the evaporator fan to be on for circulation without cooling.
In your case, I would buy one double pole 20 amp contactor for compressor and condenser fan, one single pole 20 amp contactor for second compressor, and one single pole 20 amp contactor for evaporator fan. All should have 12V coils (for control voltage). You then need a 2 stage cooling battery powered digital thermostat. You will have to pick up 12V to power the control voltage circuit. You have the original wiring schematics so that should not be a problem. Once installed, you have a simple control circuit with readily available components.
TOM
Hannah and Tyler, hope you are able to get your AC working again. The basement mounted unit must be very quiet. There are at least 2 oddball Foretravels in existence now yours and mine. I wanted to post a link to what I did but do not know how. Search the forum for 1996 U270 Dual Central Air Conditioning. What I did will not help with your problem. I agree with what Tom said about relays, capacitors, thermostats, etc. A good AC tech should be able to get it going if you can not find a board. In case anyone is wondering my setup is still working, only trouble was a capacitor that needed to be replaced.
Here you go, Jerry:
1996 U270 Dual Central Air Conditioning (http://www.foreforums.com/index.php?topic=16993.0)
We took a few days off, now we're back at it! Going to be doing some research on some of the suggestions of building something to control the unit without the board. Got a friend who understands the electrical a lot better than I do to help. There's a good chance it'll go nowhere but it sounds really interesting!
Haven't heard anything in a while from Hannah & Tyler. Hoping they will see this, and update their progress (I assume) in getting the basement A/C fixed. Always hate to be interrupted in the middle of a gripping good yarn, and then never find out the ending.
Hey guys,
A guy on the Newellgurus site contacted us and offered to build a board for us if we'd test it out and give feed back. He is trying to create a permanent solution for his fellow Newell owners and we'll be able to beta test for him. Hopefully that all works out, in the mean time we've replaced our entry door exterior latch and installed a trik-l-charge in the engine compartment and we were wanting to have our patio awning replaced but changed our mind after we got the estimate $$. I went back to work for a while since the house hasn't sold yet, and haven't had much of an opportunity to do much work on the place. I apologize for letting the ball drop on this thread but we haven't really made much headway. We do appreciate the continued interest though so thank you for that.
The guy that was helping us with the circuit board emailed me this morning to let us know that Newell Coach had finished making their replacement boards for the RVAC 2702 . I called Newell this morning and they explained how they had the board reverse-engineered to function and appear very similar to the old SCS boards but that they had fixed the weaknesses found in the original and they have already replaced several of their clients old boards with the new version without issue. They had five left in stock so we ordered one before they ran out, cost for the board was around $632 after tax. We are from Miami, Ok where Newell Coaches are made so I had my mom grab it today and hold it until we get back to the area in Feb.
We have air conditioning again!
We got back to the tulsa area on Saturday, picked up the new board on Sunday and got it installed yesterday. The project went smoothly, Newell did an excellent job of making the new board user friendly. It took a little longer to install than it could have only because I cut out all of the old janky taped and wire-nut splices in the thermostat loom and soldered all of the joints together. Other than the soldering it was really just plug-and-play. That being said, I was still a bit nervous flipping the breakers on for the first time haha but there was no flames and everything worked just like it should. We've got a new Coleman 6636-3441 thermostat on order to replace the slightly burnt original. After that's installed we'll be good as new!
Thanks very much for coming back and telling us the good news! Happy to hear your extremely unique coach is COOL again. Safe Travels!
Glad to hear you found a solution to your problem, and although the board sounds expensive, maybe the cheapest solution after all.
Would like the contact you had for Newell for the replacement.... need one as well
We called the Newell plant in Miami, Oklahoma and ordered one. Older Newell coaches had the same setup and there were no more boards to be had, so they had some new ones made up with beefier components and better design.
That's great news! Glad you checked and found a good solution.