Both AC's quit.

[real4u2c]

Quick history all.

AC's were running, then back ac quit last week, Fan runs on high and low no problems , compressor wouldn't energize, slight hum. This morning, front ac fan was running, but compressor wouldn't start and a terrible odor, something melted maybe??? Anyway, after I open the windows and ran the fantastic fans a while, I ran both ac's on high and low fan, all was well,. Tried to run the ac's for cooling and heard compressors try to start, followed by a humming, I turned them both off immediately, oh and no breakers tripped and no fuses burned. Any suggestions will help, thanks. I got Rv on a dedicated 30amp / 125vac feed, and excellent line voltage / and amperage protection in the Rv, fed from my 200 amp house panel.

[Dale_Traveling]

If you find the "why", that "why" is probably hanging out with the "Meaning of Life". Caps blow. Had the start cap on the much newer homestead heat pump failed last year with no warning on the first 90 degree Friday evening a few months after the warranty expired.

Replacementing caps are easy to do. Additional info - Installing Hard Start Capacitor

[real4u2c]

And the search continues on the "WHY" all of a sudden this decide to happen, I also looked hard for frayed wires, i searched all over my rig for that possibilty, and even changed my rv extension cord in the off chance their was a break in the plug ends,.

[real4u2c]

Thanks for all the help. I climbed on the roof, removed the shells, and the motor run capacitor on the forward ac was exploded, goo everywhere in its cage, Thus the smell. The other capacitors were somewhat melted. The rear ac wasnt as dramatic, things got warm, but no explosion. Now comes the frustration of finding the parts and more Virginia humidity on the rooftop.

[SidecarFlip]

Just be sure before you stick your fingers in the capacitor cage you short across the terminals on each and every capacitor. They can kill you if the discharge into your body.

[pianotuna]

If you mean the "standard" low voltage protection from Progressive, or Surge Guard, 103 volts is, too low for my comfort zone.

It's not pretty when voltage momentarily drops to 80.

What are you using for amperage protection?

real4u2c wrote:
and excellent line voltage / and amperage protection in the Rv, fed from my 200 amp house panel.

[wa8yxm]

Where I am just now running one is giving me fits.> They keep overloadign the 20 amp branch breaker.. I can't go topside till Monday at the soonest so....

[real4u2c]

My next jaunt is the roof, when i have a rain free day. Capacitors have ummph to start the compressors, and i got no ummph.

[real4u2c]

Well, I got one of those intellitec thermostats ( which i had refurbished last year along with the ECC relay), and its supposed to be able to cyle both, but, alternating the compressor ( their not supposed to be running at the same time)s. After painstakedly tracing hand over hand the power feed from my home panel to and in the rv. It was hell getting at the feeds for the power distribution center, all good, terminals all good, I removed each breaker and inspected the bus bar, all good, no tale tales of arcing, and removed every fuse and checked continuity ( All Good), terminals are tight. So I ran the onan in the off chance I was having a shore power amperage issue. Made no difference, compressors try to start as on shore power, then locked out. Low and high fan run like "scaulded dogs", but the compressors dont have the ummhp. So next step is on the roof to check the capacitors, and to see if anything Has tried to make my RV its house too! So the search goes on.

[DFord]

Running two air conditioners on 30 amp service for any length of time isn't possible without having problems. Even if you don't trip the circuit breaker you'll melt the plug on your power cord. I seen a few RV with two air conditioners that didn't come from the factor wired for 50 amp but that doesn't make it right and always causes troubles.

[rgatijnet1]

I know that you say you have excellent voltage at the outlet but I'll bet that if you checked at your RV electrical panel, when the AC's are trying to start, the voltage will be dangerously low. Checking voltage without a load is not giving you accurate information. As an example....if all of the wires in your RV power cord are frayed, except ONE strand, your voltage will still read at 120 volts. Once you try to draw a large load, like AC units, that single, or several, strands cannot handle the current draw and your voltage inside will drop to probably close to 100 volts. This can be loose or frayed wires starting at the plug, and moving back to where they connect to your RV electrical panel. Obviously you want to be careful when working around the electrical panel, especially if you are not sure of what you are doing.

[dougrainer]

Running 2 AC units is not advisable on 30 amp service. EVEN if you have the Low amp model AC units that pull about 10 amps each. Smell is probably the capacitors have failed and the wiring melted slightly. You need to go on top and access the Capacitor cage and verify the wiring is intact at both the capacitors and connections to the Compressors. Doug

[Artum_Snowbird]

It is symptomatic of a loss of voltage. The A/C tries to draw full power, and the voltage drops, current goes up, and things fizzle and smell bad.

This is usually caused by a loose connection somewhere either in the feed out to the air compressor, or back from the air conditioner.

In your case, because you have had trouble with both A/C's, it is quite likely in the breaker panel and it could be either the feed to the positive buss in the panel, or the feed to the negative connection buss in the panel. Remember, the wires that are in your plugin connection feed that panel. Having a loose wire there would definitely cause your loss of starting voltage.

Also, check your plug. Also check the feed where you plug in. Can you reach to a different receptacle? Maybe you already have, and that would prove it is in your rig somewhere.

If I had to bet, I would start with the negative bus connection first. While you are in there, tighten all the screws holding wires.

[Songbirds]

I'm wondering if at some point the A/C units came on at the same time? This would create a power surge and can blow one of both FUSES. Replace after checking them an offset temp so as to prevent coming on at the same time again.

[MountainAir05]

Add start/run capacitors

[rgatijnet1]

Have you checked in your RV line cord plug for loose frayed wires?