AC Issue

Rooskie

Member
I fired up my AC unit for the first time today this summer. Ran great for about 10 minutes, then shut off. I did not reach the desired temp that I had set it for. I have checked all the fuses that I can find, and none are tripped/blown. When I turn it on, I can hear a click noise like a solenoid, but nothing happens. Has anyone had this issue before? Its only about 101 degrees outside, it would be nice if I could get it running again.
 

Sumo

Well-known member
I had a similar sound coming from my AC. My problem was power shortage. I was trying to draw more power than I had available from my 3000 watt generator. Are you hooked up to shore power or running off a generator?
 

Bob&Patty

Founders of SoCal Chapter
What fan setting is it on. Is it hot and humid? If you had it set on low fan and it is hot and humid...the compressor may have frozen up. Let it set awhile and see if it will start up again. Set everything on auto. You have to move alot of air over the condenser and evaperator core when it is humid and hot.
 

Bob&Patty

Founders of SoCal Chapter
OK, that helps. Are you on 15...30 or 50 amps. Did it trip the house breaker? When its that hot low fan wont do it....set it on auto. Low fan can cause the evaporator to freeze up and lock up the compressor. The A/C is on its own circuit...thats why I asked if it trip the house breaker. It will not effect anyother circuits 120 AC or 12V DC.
 

Rooskie

Member
OK, that helps. Are you on 15...30 or 50 amps. Did it trip the house breaker? When its that hot low fan wont do it....set it on auto. Low fan can cause the evaporator to freeze up and lock up the compressor. The A/C is on its own circuit...thats why I asked if it trip the house breaker. It will not effect anyother circuits 120 AC or 12V DC.

30 amps down to 15 to plug into an outlet in my garage. I did not trip any house breaker's, just stopped working and will not come back on. My thermostat only has fan, cool, heat. No auto. Ive shut the whole thing off and will wait to the sun goes down tonight and see if it magically begins to work again.
 

danemayer

Well-known member
Is there an extension cord involved? Voltage drops across long wiring runs and you might be underpowering the compressor and blower on the AC. The click you hear is a relay that the thermostat is triggering. The relay supplies 110V to the AC unit to run the compressor and blower.
 

Theresau

Well-known member
Sounds similar to what we experienced with our AC at home when we tried to use too small of a generator.

I fired up my AC unit for the first time today this summer. Ran great for about 10 minutes, then shut off. I did not reach the desired temp that I had set it for. I have checked all the fuses that I can find, and none are tripped/blown. When I turn it on, I can hear a click noise like a solenoid, but nothing happens. Has anyone had this issue before? Its only about 101 degrees outside, it would be nice if I could get it running again.
 

Rooskie

Member
Is there an extension cord involved? Voltage drops across long wiring runs and you might be underpowering the compressor and blower on the AC. The click you hear is a relay that the thermostat is triggering. The relay supplies 110V to the AC unit to run the compressor and blower.


There is, and I thought of that. It has never been an issue before though.
 

evolvingpowercat

Well-known member
There is a thermal saftey switch inside the compressor of the AC unit. That could be opening if the unit runs 10 min and then shuts off. If you can let it set for 30-60 minutes and then it starts up again and the cycle repeats that may be the issue. Reasons for the overheat could be: 1: The run/start capacitor in the AC has failed and needs to be replaced. 2: Blocked air flow due to bird nests or wasps nests in the roof top side evaporator coils. 3. The evaporator fan that blows air thru the evaporator coil is not working right. 4. Compressor motor bearings are failing or if can be lubricated need attention. 5. Contaminated refrigerant has clogged something called the expansion valve in the coolant loop. 6. System has lost coolant due to a leak in the coolant loop somewhere. (generally lost coolant won't cause the run 10 min and trip issue though, it would just run continuous and not cool)

- if you measure the air outlet temp during that 10 min is there a 20 degree or so difference between inlet temp and outlet temp? There should be. If not there is a problem, I have listed some of the typical issues with Air Conditioning systems above.
 

Rooskie

Member
Im thinking that this is more of a mechanical issue. It has not "reset" itself; nor has it started running again. It only ran for the first 10-15 minutes several hours ago. Nothing since. I took the cover off and there are no nests, birds or otherwise. Its plugged into an outlet in my garage at my house, not a generator. None of the house breakers are tripped. Good thing we will be up around 9500' this weekend.
 

danemayer

Well-known member
There's a metal box in the air return, which is where you probably heard the clicking sound. That relay supplies power to the A/C unit and if something is wrong there, it wouldn't be getting any power up to the roof. You might want to get an inexpensive non-contact voltage tester from a hardware store (<$20, but don't bother with the ones that are <$10) and check the wires on the roof to see if it's getting power. If not, you could carefully open the metal box above the air return to see whether power is getting across the relay. When the box is open, be careful where you put your hands.

Or it might be time to get a service tech involved.
 

pegmikef

Well-known member
IMHO 15 amps is pretty marginal to be starting an AC on considering that the converter is probably sucking some of that amperage and any line loss incurred in the hookup cord.
 

Rickhansen

Well-known member
IMHO 15 amps is pretty marginal to be starting an AC on considering that the converter is probably sucking some of that amperage and any line loss incurred in the hookup cord.

That's not opinion, that's fact. That's why the breaker size in the rig is 20A. I am puzzled why, especially with an extension cord (?? wire size and length unknown) in the mix, how the A/C would have started at all.

I'm betting that the extension cord is now "deceased" and the A/C and RV will be fine when plugged into a proper source without adapters and cords.
 

ParkIt

Well-known member
That's not opinion, that's fact. That's why the breaker size in the rig is 20A. I am puzzled why, especially with an extension cord (?? wire size and length unknown) in the mix, how the A/C would have started at all.

I'm betting that the extension cord is now "deceased" and the A/C and RV will be fine when plugged into a proper source without adapters and cords.
Would agree there are some fried extension cords looking for a new home at a recycle place.
As far as it firing up on a 15A I've noticed it will draw just enough to get it running until it cycles out from lack of power. We had a 'new' guy working on our lot in 90º weather that plugged three units in on a three prong 16 gauge extension cord and plugged it into our outdoor 15A outlet used for vacuum cleaners and smaller items. The sighs and eye rolling that went round the office inside as to why all AC's stopped working was rampant to say the least.

Try getting it hooked up to a full 30 or 50A direct to power source, if there is a CG or friend with one on their house close by you may want to see if they will let you test it there, pretty sure you are under powered and the AC unit is not going to come back on until it has sufficient juice.
 

Gary521

Well-known member
Most newer houses are wired with 14 ga wire. So if you try to run an AC on these wires, there is not enough power. In my daughter's newer home, she can't even run an air compressor on some garage outlets.
 

pegmikef

Well-known member
Most newer houses are wired with 14 ga wire. So if you try to run an AC on these wires, there is not enough power. In my daughter's newer home, she can't even run an air compressor on some garage outlets.

That's interesting because our local code here in San Angelo for resdential for years has been 20 amp circuits with nothing smaller than 12 ga wire and 10 ga or larger for the 220 circuits.
 

herefishy

Well-known member
Our thermostat also has only fan cool and heat on it, but if you put it on "fan" and then watch it, if you push the + and minus sign, it will cycle thru the settings for the fan.
 

Rooskie

Member
Tried this and found that power is going everywhere it should, as far as my neighbor electrician can find. With no luck in fixing myself, or with his help, I called the local repair shop and found that the AC is still under warranty. Getting repaired now. Thanks for the advice and help.
 
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