2004 Basement AC Capacitor Question

[Hubb23]

All,
Popped my unit open today and found a burnt wire on the compressor relays located in the top right of the access panel. Replaced this wire and unit sounds completely different. I have not confirmed that the other compressor is running but seems like cooler air is flowing.



I also noticed a spot above the start up capacitors on the bottom left that looks like something has been on fire! Anyone ever seen anything like this? I'm thinking of replacing control board to be safe. Any input is appreciated.

[BobC]

There's a lag between #1 starting and #2 starting, so, if you listen carefully it should be obvious.

[Hubb23]

Originally Posted by BobC

There's a lag between #1 starting and #2 starting, so, if you listen carefully it should be obvious.

Thanks Bob but I'm not hearing it. If I flip breaker for compressor 2 off, I cant tell any difference in sound.

[BobC]

Then something is amiss. If compressor 2 was running, you'd know it, it's not subtle.

[BobC]

You never responded to me about your power situation I asked about in post #39. You should eliminate it as an issue before going any further.

[Hubb23]

Originally Posted by BobC

You never responded to me about your power situation I asked about in post #39. You should eliminate it as an issue before going any further.

Hi Bob,
I'm hooked to 50 amp shore power at the house. I have the same issue on generator power and at the campgrounds.



Since replacing the burnt wire today, the AC has been running steady for about 4 hours. It may be in my head, but I feel like its colder. Isn't hot enough in NC today to tell if the unit is still struggling. I've included a picture of the wire from the relay that I replaced.


I went ahead and ordered a new control board and relays, just to sleep better.

[BobC]

I'd order a complete set of capacitors as well, they're relatively inexpensive and you might as well eliminate them as a potential source of trouble. Good luck and keep us posted.

[al1florida]

Originally Posted by Hubb23

Thanks Bob but I'm not hearing it. If I flip breaker for compressor 2 off, I cant tell any difference in sound.

Isn't there a display on your power center that shows the # of AC power amps being used? It does not show the amp reading when on 50amp shore power, but will when on generator or 30amp service.

You should be able to use that to see how many amps are being used.

If the only thing you have on in the RV is the air conditioner you will see about 13-14 amps when just one compressor is running and about 19-21 when both compressors are running. Be sure the gas/elect fridge is off or on propane.

[Hubb23]

Originally Posted by al1florida

Isn't there a display on your power center that shows the # of AC power amps being used? It does not show the amp reading when on 50amp shore power, but will when on generator or 30amp service.

You should be able to use that to see how many amps are being used.

If the only thing you have on in the RV is the air conditioner you will see about 13-14 amps when just one compressor is running and about 19-21 when both compressors are running. Be sure the gas/elect fridge is off or on propane.

Al, Good call!
Just went out and fired up the generator to try this out. Started out at 0 amps, then 14 amps when the ac kicked on, then a few seconds later jumped to 20 amps and stayed there. Coach reached 68 degrees inside earlier today in NC. Something that it has not done in the short time that I've owned it, so I was hopeful that the issue was resolved. This confirmed it for me. I'm still gonna change that board out and the relays. I'm still nervous about that black soot I seen, but I feel better once the board and relays are changed.

Thanks Everyone!!

[BobC]

I wonder why it doesn't work on 50A shore power but will work on the generator. Maybe something is amiss in your automatic transfer switch. You might want to open it up and tighten down all the connections and see if that makes any difference. And look for any burned wires there as well.

[Hubb23]

Originally Posted by BobC

I wonder why it doesn't work on 50A shore power but will work on the generator. Maybe something is amiss in your automatic transfer switch. You might want to open it up and tighten down all the connections and see if that makes any difference. And look for any burned wires there as well.

Bob, I think it is working on shore power since the burnt wire was replaced. My untrained ear can not hear the 2nd compressor kicking on, but the difference in AC temp got my hopes up. Firing up the generator and looking amp display confirmed it for me.



We've got a short weekend trip planned in the morning, I will know for 100% by Sunday.

[al1florida]

I believe you will find that both compressors are running on both shore power & generator. You just can't see the amperage display on 50amp shore power.

One other thing to keep in mind, if you don't have the thermostat 3 or 4 degrees below the temperature displayed on the thermostat only one compressor will initially run. If the thermostat detects that after some amount of time passes the temperature is not falling fast enough or continues to go up, it will finally turn on the 2nd compressor.

[cef2lion]

When Im on 50A i can see the AC amp load on my Surge Protector. It scrolls through load on both legs.