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Both AC's quit.

real4u2c
Explorer
Explorer
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.
Retired Marine with Retired Navy woman2004 Fleetwood Pace Arrow 37 C, Workhorse p32 chassis, 8.1l gas engine.
29 REPLIES 29

real4u2c
Explorer
Explorer
I have an autophormer, **** nice peice of equipment. My ac's were old, I am not sure what brand will work with my older than dirt thermostat. I have contacted a few online sites to get some feedback. But the best recomendations come from this site, RV owners.
Retired Marine with Retired Navy woman2004 Fleetwood Pace Arrow 37 C, Workhorse p32 chassis, 8.1l gas engine.

pianotuna
Nomad II
Nomad II
Low voltage does that. Look into an autoformer.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

real4u2c
Explorer
Explorer
New ac's, is there one better than the other?
Retired Marine with Retired Navy woman2004 Fleetwood Pace Arrow 37 C, Workhorse p32 chassis, 8.1l gas engine.

real4u2c
Explorer
Explorer
Both compressors fried, any suggestions on brands?
Retired Marine with Retired Navy woman2004 Fleetwood Pace Arrow 37 C, Workhorse p32 chassis, 8.1l gas engine.

down_home
Explorer
Explorer
20 amp shore power??? I missed that. It will not bode well for your ACs and other devices.
When we stored our unit on 20 amp we had to start the generator to use AC while preparing to head out. I might well run one ac and nothing else.
We have an inexpensive volt meter plugged in near the stove.If ac power drops below 105 we cut on the generator. AC load handling system will shed devices to save them. We can run two ACs on 30 amp but but system will shed loads including one AC if necessary. if the volts are normal between 110 and 130.
Don't try to run even one AC along with anything else on 20 amps.I think it takes 23 amps t start and goes down to 14 amps to run one ac.

pianotuna
Nomad II
Nomad II
real4u2c,

If I understand you correctly, you are attempting to run 2 air conditioners on one 20 amp shore power supply with both running?

That may be likely to result in quite low voltage.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

DFord
Explorer
Explorer
Start capacitors are only there to provide a boost to the compressor to get it started instantly. They provide up to 5 times the torque to get the compressor spinning than without one. They are not meant to be in use from more than a split second or they'll fry themselves. Capacitors are made by tightly wrapping aluminum foil and waxed paper around each other. When they overheat, the wax melts and boils creating pressure that spews out the top of start capacitors or bulges the top of run capacitors. One time is all it takes to ruin them. The run capacitor is in the circuit all the time but a relay of some type. The mechanical relays of old had contact points that could stick closed and ruin the capacitor. New methods use a solid state device that's operated by heat. Run capacitors are most likely damaged by spikes in voltage that burns a hole between the layers of foil and short out the capacitor.

It's hard to find any made in the USA today but they are considered much better quality and closer to specs than those made in China but cost wins out almost every time and China has the market cornered right now.
Don Ford
2004 Safari Trek 31SBD (F53/V10 20,500GVW)
'09 HHR 2LT or '97 Aerostar MiniVan (Remco driveshaft disconnect) for Towed vehicles
BlueOx Aventa II Towbar - ReadyBrake Inertia Brake System

wa8yxm
Explorer III
Explorer III
Well I got my new start caps in as well.. Great improvement but not yet 100%

Still trips in the EXTREME heat we have this week but Sunday is supposed to be better and holds all night now.. and most of the day.. Trippy from about 2 to 6 PM of course it just started raining so it's working fine in the rain.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times

down_home
Explorer
Explorer
real4u2c wrote:
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.


Capacitors!Just about everyone has to replace one during ownership.
The smell was the rubber/plastic capacitor case etc trying to burn.
This has happened a lot over the last decade.
Had a conversation with AC parts warehouse mgr. Home units RV units.
He has those marked made in the USA but are identical to ones marked made in China because they are but cost $10.00 more.
Home units replaced four in to years. So far on RV replaced two. Found old ones, made in the USA in Elkheart Indiana.
We have two new units for home and so far in a year not replaced capacitors. They don't have to be identical to the old ones to work and ones marked with a higher rating will work as long as they have have the required spades. Extras on it don't matter is what he said. ..but they do have to fit need to be held in palace by that clamp or something.

DFord
Explorer
Explorer
If it's the "start" capacitors that are blowing that quick it's because they're in use too long. The start capacitors are usually round in black hard plastic cases. There is a "start relay" that should take them out of the circuit (disconnect) them as soon as the compressor reaches 3/4 full speed (that like the blink of an eye). They're only designed to do that 60 times an hour without damage. If they're in the circuit any more than that they overheat and fail very quickly. That could also damage the start windings inside the compressor.
Don Ford
2004 Safari Trek 31SBD (F53/V10 20,500GVW)
'09 HHR 2LT or '97 Aerostar MiniVan (Remco driveshaft disconnect) for Towed vehicles
BlueOx Aventa II Towbar - ReadyBrake Inertia Brake System

MountainAir05
Explorer II
Explorer II
Have you check the connections in the power panel , cord that has been posted, and also try only one unit and see. As units get older they draw a little bit more usually. If it blew the cap with only one unit and all the connections are good , then the compressor might have a short in the winding. Doug might be able to give you the ohms, and the max starting amps.

real4u2c
Explorer
Explorer
Okay, I replaced all the capacitors using the part numbers on the older capacitors, one at a time , wire for wire so no cross connection would take place. I checked continuity across the compressor windings, all good, I inspected anything electrical on the roof for frayed wires, bad connections, terminals, 3 corroded terminals which I replaced with correct size. Plugged in house juice, front ac ran for 45 seconds, then died, almost same for rear ac. Climbed back on the roof, same capacitors as before were blown. Dam this has stumped me. I have checked everything electrical & mechanical hand over hand of what I could get access too.
Retired Marine with Retired Navy woman2004 Fleetwood Pace Arrow 37 C, Workhorse p32 chassis, 8.1l gas engine.

wildmanbaker
Explorer
Explorer
If you need the caps in a hurry, try an H & V firm/installer. They will be more that on the interweb, but if you need them, you need them. Just like the price of fuel in out of the way places, it may be high, but a bargain if you really need it.
Wildmanbaker

DFord
Explorer
Explorer
If there's any puffiness to any of the capacitors - replace them.
If there's any sign of damage to any of the capacitors - replace them.

"Run" capacitors are in metal cans and offer a failure is indicated by the top bulging up - a sure sign it's bad.

"Start" capacitors are usually in a hard plastic shell. The number of starts per house is limited and likewise, if they're left in the circuit very long, they'll overheat and began spewing their contents just before they short out and become useless.

It's also possible for them to go bad without any sign of damage. In that case, you'll need a meter to tell if they're any good.

http://www.capacitorformotor.com/starting_capacitor.html

http://www.hvachowto.com/2014/11/12/start-run-capacitor/
Don Ford
2004 Safari Trek 31SBD (F53/V10 20,500GVW)
'09 HHR 2LT or '97 Aerostar MiniVan (Remco driveshaft disconnect) for Towed vehicles
BlueOx Aventa II Towbar - ReadyBrake Inertia Brake System