Hello,
I am experiencing less than sufficient air conditioning temperatures in the coach. I  have the Specific Climate System (SCS) R-VAC 2702 52128.  It has 2 compressors  and is reversible ,providing heat or cooling.  I need to know how to access the evaporator coils.  I have cleaned the condenser coils and replaced the filter.  I have found a 'grill' under the unit towards the centre of the coach .It is beside the area where the   water drains out though 2  1 inch diameter holes. If I remove this grate/cover/will I have access to the evaporator coils??
All sugestions will be most welcome.   Jeremy

Nothing in the AC system is accessible from under the coach. The outside (intake side) of the condenser coils is accessible through the two large ducts on the side of the the coach in front of the utility bay and the outside of the evaporator coils is accessible through the access door in the basement were the filter is located.

The first step in troubleshooting a low cooling complaint on the basement AC is to check the amperage draw on the compressors. You can do this by watching the coach monitor panel that is located above the dinette on most coaches. First turn off the AC and wait 5 minutes, then turn the AC on with the thermostat set at least 10 degrees below interior temperature. Watch the monitor to see how many amps the first compressor draws when it comes on, which is usually a minute or so after the fan starts. A few minutes later the second compressor will turn on which will be indicated by a change in fan speed. Watch the monitor on the other power leg (if the first compressor was on leg one the other one will be on leg two) for the amp draw on the second compressor.

If both compressors are drawing in the 13 to 16 amp range (depending on the heat load), and they are drawing the same amperage, the system is operating to spec. and no repairs are indicated, but if one compressor is drawing considerably less amperage, you have a refrigerant (R 22) leak  that needs to be repaired, If one of the compressors draws no amperage, you have a control board problem or a bad compressor.

SCS Frigette (the manufacturer of the unit) declared bankruptcy and went out of business the first of this year. Before they closed down, they were an excellent source for troubleshooting help, parts, and repairs on the unit. Now it looks like we will have to get the units repaired by a residential AC repair tech after the unit has been removed unless you have a control board problem, and that would have to be repaired by an electronics tech.  

Gerald

Hi Gerald
  many thanks for your informative reply.  I will at least be able to clean the coils now and find out if both compressors are operating normally.  Jeremy

Hi Gerald.
Ok I checked the control board. All is working as it should.  
There is no access to the evaporator coils after removing the air filter. I am looking at a black plastic top of the unit.  
I spoke to Beaver in Oregon and they tell me access to the evporator  coils is  through the basement storage on the cargo side  .I will check this out and report as soon as I have access.  

The air filter on my 2000 Marquis is located behind the basement access door. It is 18 inches high by 36 inches long. There is a tray on the air conditioner case that the filter sets in, and the top of the filter is taped to the A/C unit with duck tape. I use a pleated filter, and change it once a year. The coils are always clean, and the filter could usually run longer, but I change it to avoid health concerns.

If your filter is inside the coach, I would recommend that you move it to the location directly in front of the evaporator coils that you are accessing in the basement. You are seeing the condenser coils through the ducks on the outside of the coach.

Gerald    

Gerald .
     I know the evaporator coils are located inside the rear storage bay behind a removable access panel where your air filter is  on your coach.
On my coach the removable access panel just reveals a black plastic housing/cover that is part of the a/c  unit casing.  
My air filter is located above the condenser coils in a tray that is accessible above the two large ducts on the outside of the coach drivers side.
Could it be that the evaporator coils are located behind the solid black plastic housing I can see when I remove the bay access panel??  Could that be why your filter tray was moved to this location??
I am considering cutting a door in the black plastic housing . The coils have to be behind this casing .It would be a simple job to fabricate a door for future access.
Directly below this area ,on  the bottom of the coach, is a removable grill about 18 inches x 6 inches through which water drains when the a/c unit is working.
After our trip to Cabo San Lucas,Baja, Mexico this winter the a/c unit is running as it should, showing leg 1 at 13 amps and leg 2 at  18 amps when the 2nd compressor kicks in,but we have no cooling. I believe the Mexican dust has totally clogged up the evaporator coils which I believe have never been cleaned.
If anyone has a similar basement unit and has managed to clean the evaporator coils I would like your input.    Thanks, Jeremy      (who was confused between condenser and evaporator coils..lol)

If anyone has the service manual for the Specific Climate System (Fridgette) 27000 btu basement a/c that was fitted to early Beavers please get in touch.  Thanks, jeremy

Thank you David Henry for sending me the SCS manual with excellent diagrams. I now know that when you remove the access panel at the back of bay with the water pump etc in it you are looking at the black panel/ducting of the a/c unit that ducts the air from the filter ,through the evaporator coils and up through the top exit duct into the coach.
Today I am going to cut an access door into this duct to enable regular cleaning of the evaporator coils.
I also noticed there was no fibreglass insulation anywhere around the unit so I will stuff as much pink stuff around it as I can to minimise the cooling loss.

I have cut an access panel out of the black plastic housing I could see behind the basement storage bay access panel. The evaporator coils were directly behind the plastic panel....about 4 inches behind so plenty of clearance for a cutting tool.
The coils were very dirty;grey ozidization , black crud.  I used a coil cleaner from Ace Hardware and a soft brush. The coils now shine like new.
  I have pictures of the work I did and the new access panel installed .If  anyone is interested email me .
Because the evap.coils were so dirty it seems we have now blown the start capacitor or something else on the circuit board as both compressors have stopped working.  
Sunland RV in Las Cruces are going to look at the circuit board .  Hopefully we will soon have an ice cool coach as we are heading east towards Florida!!
I phoned Victory Climate Systems in Fort Worth. http://scsfrigette.com/  They do have some old parts from SCS systems,but not my circuit board.
  

Sunland RV In Las Cruces were unable to service the SCS Basement unit.
Our  coach is now in Wildwood.FL at Alliance Coach,the old Monaco facility. They tell me the freon level is low in the SCS Basement unit. Both fans and both compressors are running but with low pressure in the freon lines we have no cooling..They need to remove the unit from the coach;install Schraeder valves ,and recharge the unit. The cost could exceed $4000 !!!!!  
We are told that Good Sam's Gold extended service plan may not cover this ,if all that is needed is a recharge. If anyone has  experience with claims like this I would much appreciate hearing about it.
We are getting quotes for installing  2  Dometic 15,000 btu roof units to be connected to the existing ducting ,controlled by a dual thermostat.
  

Price sounds kind of high to replace freon. But first have to find where it leaked out at and repair. I would think you could install the valves with out removing the unit. I know they work a little slow at Alliance, as I had front wheel bearings changed over to wet to the tune of $800.00 there last year.  It was an all day job.  As I have worked in havc for 40 years, I do know a little about mechanical work.

Hi Forrest,
   Thanks for the information.  Do you think the Schraeder valves could be installed from the front of the unit if we cut an access panel into the space between the coils from the the side facing the generator ??  
By removing the water bay, the other end of the unit can be accessed by removing a panel behind the circuit board/capacitor area, but working in there might be very difficult.

All they have to do is find a low pressure line and hi pressure line to install the valves.  They can also use saddle valves, but personnel I don't like them, as they are more prone to leak, but I have used them and they work just fine if installed properly. But still will have to check for leaks to see where you are losing the freon. Some units have a real slow leak, and you can charge them.  They will last a year, then just need to recharge every year.  Not a very good route to take, as I would want to repair the leak if it can be located.  With the new electronic testers, they should be able to locate the leak.

That seems well beyond what this kind of work should cost. I do not know if the unit has to be removed to add the ports or what is involved in getting the unit out. Someone who has removed one before may be able to comment on how many hours of work is involved.

I would look on the web for a well rated residential small heat pump/ air conditioning outfit and tell them that you have a basement air system that has been diagnosed as having low freon and you would like them to leak check it, silver solder schraeder valves on the low and high pressure lines of each unit (I believe that both are a problem?), pump them down, check for vacuum leaks and recharge them. I have had R22 air conditioning systems lose some charge over a period of 10 -12 years and then be recharged and run just fine for many more years. The leak rate is so slight that it will never be found and you will spend a lot of time and money chasing it. Tell them that you would like the charge ports located and extended in a fashion that would make it relatively easy to service without removing the unit in the future. That will insure that any future recharge will be relatively inexpensive. There are people that do this type of work everyday that are not charging Alliance rates. Marine air system service folks may be another source of alternative help.

Later Ed

Roy Mueller has removed the basement air several times for Lamar.  As he described it, after removing the two air intake tubes and disconnecting the wiring, there are only 4 bolts holding the unit to the floor.  Slide it out, repair and replace.   You may want to contact Roy with questions.

Larry

Jeremy, $4000 to recharge your A/C is a ridiculous price. Last year my basement unit was no cooling on the secondary system, so I took the unit out in about 2 hours by myself and took it to SCS, who was still in business at the time. They replaced a leaking line and recharged the unit for $200, and I reinstalled the unit. Total repairs, $210 (SCS service, silicone calking,and duck tape) and 3 hours labor (N/C on labor).

Any competent home A/C repair service can fix the unit unless you have a circuit board problem. The unit uses R-22 refrigerant an operates just like a mobile home A/C unit except it has 2 compressors. So it operates like two A/C units that are built together in one housing, and controlled by a special thermostat and circuit board.

The unit will have to be removed to check it for leaks and to recharge it. The unit is not that hard to remove. After removing my unit once, and learning how, I could remove and replace the unit in 2 to 3 hours working alone.

If you have anyone remove the unit, be sure that they repair the leak, and not just recharge it, because you will have to remove it again to recharge it again when that refrigerant leaks out, and it will.

Gerald      

Thank you all so much .  
Gerald,would you be kind enough to explain your removal procedure to me in detail.  What equipment will I need to move the unit which must weigh 200lbs or so?? Do I need to lift the coach? Does the water service bay panel need to be removed?
It is obvious that Alliance Coach have absolutely no knowledge of the Beaver Marquis set up.

Jeremy,
Give me a call (713-254-4156) sometime and I should be able to walk you through the procedure to R&R the unit. I am at my ranch in Texas now, so I will be busy during the daytime, but I will be aviable between 7 and 10 PM most days. Since I am reroofing a house today, I am only inside the coach now to get out of the sun for a little while.

If you would perfer to use email instead of a telephone, my email address is    <GeraldFarrisBAC@gmail.com>

Gerald

I contacted Alliance Coach this morning.  I forwarded  Gerald's directions to them.  They have agreed to keep a strict record of the hours this job takes although they do not think they can remove the unit in 2 hours.  They are telling me there is a vertical beam that has to be removed to allow the unit to slide out. I assume this is the  part of the frame that the sewer/water bay door latches are attached to. Gerald 's instructions mention sliding the unit forward and then out ..........to avoid this beam ???

Alliance Coach rang me this morning. The HVAC tech says that because the evaporator coils were so dirty,the compressors over heated the freon  and blew the copper tubing off both compressors.  I am not sure what they mean as the evaporator coils are the outside ones and  they were reasonably clean !!
Either way ,a claim is being submitted to Good Sam's for a replacement unit of equivalent btu's.  The saga continues.....

As the saga continues. The evaporator is on the low side pressure of the unit an the condenser coils are on the high side of the unit. I would think that there was a high pressure switch build into the unit that would shut it off if pressure got to high also some units have a low pressure switch on the evaporator side also. I would be surprised that it did not burn up the compressors if it gets that hot. I would not be putting to much faith in that a/c mechanic as I don't think he knows  what he is talking about.

Hi Forrest,
  The SCS unit does have pressure switches on both low and high pressure sides. I also know I cleaned the evaporator and condenser coils as well as I could from the outside and thru the basement storage access door.  
I suspect Good Sam's will question this diagnosis and might want to inspect the unit for themselves.I cannot believe that the SCS unit cannot be repaired.  Coils,compressors,copper tubing,capacitors etc do not cost much compared to a new unit.  Maybe I am wrong.
I will call Alliance Coach tomorrow .  I know they are monitoring this website now which is a good thing.
They told me this morning they want to replace the SCS unit with a new RVP unit of similar btu's. (Coleman>?  They have found one somewhere.
It would be common sense to upgrade to a unit that runs on R410 as I believe the older units that use R22 will become unserviceable very soon.  

Jeremy,
Your information on A/C refrigerant is not correct. New R-22 systems can not be manufactured after 1/1/2010, but it will be available to service existing systems until 2020, and after that it will have to be recycled to service existing systems. So there is no worry about the availability of R-22 for years.

There is also a concern with R-410A because it has been shown to cause global warming just like R-22 if you subscribe to that theory, but it does not cause ozone depletion, so it has been approved as a R-22 substitute.

R-410A also has higher operating system pressures than R-22, so it is more difficult to design a motorhome system that will not leak because of the vibration in a motorhome with the higher pressures. The early R-410A systems also had higher compressor failures because of the higher operating pressures, but I think that the problem has been corrected.

Also the diagnosis that you got on your SCS unit is hard to understand how a qualified A/C technician could come to that reasoning and harder to believe since you said that your compressors were running and they could not run without refrigerant.

Gerald

    Alliance Coach are sending photos of the SCS unit damage.   The service advisor is telling me that   the cause of the failure has been relayed through several parties and so the exact reasons may have become blurred !!  I   remember their original diagnosis stated the compressors were running ,but the freon level was low.
     Thanks for the info on R22 Gerald. If Alliance Coach install a new RVP unit that uses R22 I need not be worried about it becoming redundant in the near future.
When I receive the photos I will try to post links on this website.

  

I have sent 4 photos to Gerald.I would post them on here . I am not sure how to shrink them to fit.
The coils look bruised but clean enough. The copper tubing that exits the top of both compressors is fractured; damage caused by vibration and old age??

It is my understanding, the factory, prior to ending business, started using flexible connectors to eliminate the vibration problem.  The repair facility may be able to make that change when they install the new charging valves.  That may be less expensive than a new unit.

Larry

Jeremy,
The photos that you sent me do not indicate a dirty coil as the root cause of your problem like you were told. However they do look like your failure was caused by vibration in the rigid copper lines to the compressor that SCS used on the early model units.

SCS discovered the flaw in this design 5 or 6 years ago and started using a flexible connector at the compressor to greatly reduce this type of failure. I would not have the unit repaired unless there is a more flexible connector installed at the compressor, assuming that the compressors are not damaged.

I will get your pictures resized and posted latter today if possible

Gerald

Hi Gerald and Larry,
  I have passed your comments on to Alliance Coach. They will advise Good Sam's  who are coming to see the unit .
Looking at the damage I do not think an "expert" could come to any other conclusion.  I am guessing this unit had been leaking at the left compressor for years.That would explain why even the previous owner said it never cooled the coach sufficiently.
Adding flexible tubing ,installing Schraeder valves and recharging the unit might work;it would be a chunk of money wasted if the compressors are damaged. I understand that if a sealed unit leaks air mixes with freon to cause a corrosive mixture which might ruin the compressors etc.

I have resized and attached the pictures of Jeremy's SCS air conditioner.

Gerald

Thank you Gerald.  Now we will wait and see what Good Sam's have to say .

Alliance Coach  are  going to reconfigure the 24,000btu RVP # 46515-811 $3257 unit to fit which Good Sams approved as a replacement .They have used almost all of the 8 hours Good Sams allowed for this job.
We are assured they will work with with us  on the hours billed as they want us to be happy with the final outcome.
It was decided rebuilding the old SCS unit was not a viable  option.
I have since been told that Beaver Coach Sales  rebuild   old SCS units for $3000 ,using your unit as a core.  However it is obvious the New RVP unit is far superior in performance even though it will cost to install.

Photos

Thank you Gerald for shrinking these photos and posting them for me.
Work started on Thursday morning ,hoping for completion by Thursday June 2nd. Memorial Day weekend means no work Friday or Monday.
Looking at the photos   the return air duct (black rectangular shape with 2 shiny screws(filter access door) and the cold air duct into the coach (top right small square duct) are at opposite ends of the new unit.  

Wednesday 1st June.
  After starting work last Thursday 26th May ,Alliance Coach have modified the return air and cold air ducting . Modification of the forward bulkhead is required to allow the RVP unit to swivel into position. A new   RVP thermostat is on order as the SCS unit is not compatible .  

Modified return air blower duct

Thursday June 2nd.
  Alliance Coach have removed the forward wall/bulkhead that supports the tray  to allow the RVP a/c unit to swivel into position. They now have to fabricate a thinner support bulkhead as the RVP unit is longer than the old SCS unit. Once the bulkhead is installed they will hook up the modified RVP  unit to the old ducting , connect the 2 110v ac power supplies and install the new RVP thermostat.  

Friday 3rd June
Alliance Coach  are fabricating new  ducting.In the bottom photo the black square metal box, above the RVP  with 2 ss screws on its face ,is the return air filter tray. The screws undo and the plate folds down to allow the filter to slide out.

Monday June 6th 2011.
  Alliance Coach has completed the ducting.  Looks good.  Presently wiring the RVP in.  Looks like the new thermostat lying on the coil of grey wiring in foreground.  The new forward bulkhead is on left.

Wednesday June 8th. 2011. Day 9 .
  Alliance Coach have told me the following:  " The a/c is ducted, wired and running; it is really cold; in a 1/2 hour while it was 95 degrees outside the coach was cooled down to 65 degrees. They also said the RVP unit is very quiet.
This might interest some of us who have to let the SCS unit run all day and night, to keep the coach at 80 deg F plus when its over 95 deg F outside.
   They could not reposition the thermostat for a faster installation as the Hurricane Furnace wiring runs inside the slide wall to the same location, which meant they had to remove the wall to run the new thermostat wiring.  The Technician has to reinstall the wall, after installing the thermostat and button things up .

Thursday June 9th .
  The final day reworking and installing the air filter access cover ,the condenser coil cover and exhaust  flex  ducts.

Friday June 10th. 2011.

   Job completed early today. We will pick up coach on Monday 13th June.

It would be good to know the final outcome of this project, especially in view of all the negative comments about being "ripped off" by Alliance Coach. I would venture a guess that the final cost was much greater than the original quote of $4000. They must have worked on the job for at least three weeks. How about an update.

Thursday 23rd June 2011.
Louis, you are correct.  After 57 hours work, not including the 8 hours Good Sam allowed for R&R of the old SCS unit, the new RVP 24,000 BTU basement air conditioner is installed and running.
The main problems were, having to alter the units cold air output and the return air inlet from the coach. After the RVP was installed,  Alliance had to  R&R  the unit to add bracing to the cold air blower squirrel cage, to stop the blower wheel from touching the side of the housing.  This was done at no cost, under the 30 day warranty, after consultations with Coleman.
It meant a return visit to Alliance Coach  for 3 days.  
We are now in Utica NY, and the unit is running amazingly well.
Alliance Coach was very good to us as far as the final bill was concerned.  We settled for just under $3000, which included the $500 deductible for Good Sam, who picked up the bill for the new unit and the initial 8  hours labor,for diagnosis and removal of the old SCS unit.  
Alliance Coach is well aware many of us are watching this site and might find ourselves needing this upgrade in the future.
Now they have this experience under their belt, I would recommend anyone needing this upgrade, go to Alliance Coach.  Just be aware some coaches are different from our Beaver Marquis Amethyst, and might require slightly different configuration.
Overall, a very frustrating experience, but the outcome is well worth it.
The new Coleman RVP unit is way more efficient than the old SCS unit.  It cools the coach down after a hot days run in less than 10 minutes.  At 95 deg outside temps, it keeps us cool at   77 degF.or lower.
It is much quieter than the SCS unit, inside and outside. Parked next to another RV, we no longer blow them off their site or drown out their conversations.
If anyone want further info, please email me at: svpelican1@hot mail.com