Hi Guru's , I have question about the circuit boards that are used in the basement Air Conditioning. Mine has been working properly until yesterday., late in the afternoon the front section of the coach started to push out warm air ( no air conditioning) the other zones were just fine, nice cold air. I turn off the front for a few minutes , it started cold and than turned to warm again. I called Newell and he said it might be a relay on the circuit board. I was told they don't make the board anymore, but, I read somewhere, that there is a place to get a new board now.
Does anyone have any info on this. Thanks again, John and Pat Hilditch, Dillon, Mt
(Others on the forum are much better at these AC units than I am so please feel free to correct any mistakes on my part)
In my coach I have two double units. One for the front and one for the back of the coach. I am assuming that is the case with you as well. While I don't disagree with Newell as to a possible cause, you might want to do a little more troubleshooting before you resort to just swapping the board.
I would start by looking at the fins of your compressor on the return side....Make sure that you don't see ice on the fins on the return side of the unit. If you do, the answer may be as simple as cleaning the filters.
Next, I would do a very careful visual inspection of the board. There have been a number of issues with bad and loose connections causing resistive heating which have caused the boards to fail.
Next, get a clamp on ammeter and see what current is being drawn by the two compressors. (See wiring diagram). There are high voltages in the box on the side of the AC unit where the board is. Don't do this unless you are competent to work on live circuits.
What current draw do you have from each compressor?
Try this with the thermostat on low as well as high. I have attached a graph from the SCS manual which tells us what the current draw should be. Significant variations from this will point us in the right direction.
You might ask Newell if they have any rebuilt boards left. (They will ask you to send in your old board). They should also be willing to tell you the name of the company that rebuilds the boards.
Cheers,
bill
Admins, Can you move this thread to the correct forum?
Bill Johnson
Birmingham, Alabama
(This post was last modified: 06-09-2016, 09:18 AM by bikestuff.)
(Others on the forum are much better at these AC units than I am so please feel free to correct any mistakes on my part)
In my coach I have two double units. One for the front and one for the back of the coach. I am assuming that is the case with you as well. While I don't disagree with Newell as to a possible cause, you might want to do a little more troubleshooting before you resort to just swapping the board.
I would start by looking at the fins of your compressor on the return side....Make sure that you don't see ice on the fins on the return side of the unit. If you do, the answer may be as simple as cleaning the filters.
Next, I would do a very careful visual inspection of the board. There have been a number of issues with bad and loose connections causing resistive heating which have caused the boards to fail.
Next, get a clamp on ammeter and see what current is being drawn by the two compressors. (See wiring diagram). There are high voltages in the box on the side of the AC unit where the board is. Don't do this unless you are competent to work on live circuits.
What current draw do you have from each compressor?
Try this with the thermostat on low as well as high. I have attached a graph from the SCS manual which tells us what the current draw should be. Significant variations from this will point us in the right direction.
You might ask Newell if they have any rebuilt boards left. (They will ask you to send in your old board). They should also be willing to tell you the name of the company that rebuilds the boards.
Cheers,
bill
Admins, Can you move this thread to the correct forum?
Thanks Bill, For your fast reply. I have the unit running , so far all is well. It happened yesterday after being run all day and at the hottest time in the afternoon. The rest of the coach is just fine, the kitchen and bedroom had cold air all day. The front is running fine now, but,I will see how long it goes today. FLIGHT SYSTEMS, INC WILL REBUILD FOR $85.00 also, it looks like there is a company called ACS INDUSTRIAL SERVICES that will also rebuild the boards. Filters are clean and does not appear to have frozen up. Thanks for your help, I'll post an update
