Bummed, barely used AC already Not Performing.

[Barkoff]

I can't believe my AC is already in need of attention!

I have a Lance 950 with Colman Mach on the roof, the blower is blowing well, the air starts out cool not cold, then instead of getting cooler, seems to warm.

The Camper is a 2013, not much use, but the generator and AC gets run for fifteen minutes at least once a month. Have never used the AC for more than a half hour. When it worked, it did a bang up job.

Any ideas, is it common for AC units to lose their coolant charge this soon? The camper has not been in any dusty areas yet,I doubt the filters or coils are dirty, only urban camping out on the wharf or along the cliffs. Are rooftop units that temperamental?

Dammit!

[Bird_Freak]

Ok electrical guru's, I'm going to throw this out here. Could he have a weak start capacitor after running such a small 100 ft cord for so long?
I'm a car guy, not a ac current tech.

[wnjj]

Barkoff wrote:
Yes the fan ran for about ten before the compressor turned on. I'm starting to lean towards my not understanding electricity, thinking a system designed to run on 110 volts would run on any 110 volts.

I think the new cord I bought is a 15amp, probablly making my old 100ft cord a 12amp.

I didn't see any at Ace with the same 110 plug that ran 20amps. So the heavy duty cord that comes attached to the Lance electrical is also a 110, but a true 30amp cord?

110V (120V most places these days), is just that but the wire gauge of the extension cord will affect the resulting voltage at the load. If the wire is too small it will act like a resistor and consume excessive power in the form of heat. A lot of typical orange extension cords are 16 gauge and will drop too much voltage when a load is pulling 15+ amps through them. You can buy 12 gauge 120V cords with the standard ends on them that are better suited. Often they say 12/3 on the package. Maybe that's what you just bought? Granted, any size wire will still have some resistance but the idea is to minimize it.

What your camper has is a 10 gauge, 30A cord. If you can pull the cord out and reach the receptacle directly (even with a small adapter to a 20A), you will have more voltage at the A/C than if you also use an extension cord (no matter what gauge).

So when others were suggesting measuring voltage with the compressor running, the difference is the high amperage demand will decrease the measured voltage at the A/C unit. If that voltage drops too much, the compressor may shut off to save itself.

So to clarify again, the compressor was 10 mins to start and then didn't ever shut off until you turned it off? If it was running for several minutes or more and you weren't getting nice cold air the unit itself may be the issue, unless when it was running it was running way too slow due to low voltage.

[Barkoff]

Barkoff wrote:
Yes the fan ran for about ten before the compressor turned on. I'm starting to lean towards my not understanding electricity, thinking a system designed to run on 110 volts would run on any 110 volts.

I think the new cord I bought is a 15amp, probablly making my old 100ft cord a 12amp.

I didn't see any at Ace with the same 110 plug that ran 20amps. So the heavy duty cord that comes attached to the Lance electrical is also a 110, but a true 30amp cord?

Probablly why it worked before back when I thought it was bad having your batteries juicing 24-7. After that lesson I keep the battery switch on even while connected to shore power, most likely that is why the problem just surfaced.

[j-d]

I'd like to see results from plugging into true campground 30A service, or at least into a 20A outlet using a short 20-to-30 adapter like this

There are little hockey-puck-looking adapters but they don't handle a load like A/C very well.
I'd be amazed if any 100-ft extension would run an A/C.

[Barkoff]

Yes the fan ran for about ten before the compressor turned on. I'm starting to lean towards my not understanding electricity, thinking a system designed to run on 110 volts would run on any 110 volts.

I think the new cord I bought is a 15amp, probablly making my old 100ft cord a 12amp.

I didn't see any at Ace with the same 110 plug that ran 20amps. So the heavy duty cord that comes attached to the Lance electrical is also a 110, but a true 30amp cord?

[wnjj]

Another test to try: Turn off the converter by turning off its breaker. It can be a huge power consumer if the batteries are low. Also turn the fridge to propane if it's on.

[j-d]

I think your issue is largely wire size in your electric supply. You got it running by going to a larger wire gauge in the extension cord and reducing its length. Both changes allow more amperage to the A/C. It needs "20-amp service" to run reliably. That doesn't mean just the breaker size that feeds the outlet. It means ALL wiring and ALL connections.

The A/C may have taken time to start for two likely reasons:

1. It has a Compressor Start Assist device (aka Hard Start Kit) that uses a PTCR device to drop the compressor into run mode once it starts. Like releasing the key in your car from Start to Run. If the device is in fact there and in fact uses PTCR, the PTCR has to cool before it can provide start assist again. That's why we don't recommend the least expensive kits.

2. Compressor had already made a number of start attempts and gotten hot enough to activate an internal hot compressor shut-off. Once that happens it can take at least 10-mins to cool and close the power circuit in the compressor. By then a PTCR device would have also cooled, and you'd stand a good chance of a clean start.

The Start Assist issue is why I asked for pix of wiring diagram and the capacitors behind that metal cover.

EDITED TO EMPHASIZE:

That shore tie cable as pictured above IS 120-volts-AC, even though it looks massive enough to make people think it's 240-VAC. Safe enough to assume that a campground pedestal socket for this cable is 120-VAC. BUT BUT BUT people (including licensed experienced electricians) HAVE (actually often) installed outlets on RVers' homes and set them up 240-VAC. It's 120!!! Just massive because it's 30-amp.
Use extreme caution installing an RV outlet OR having one professionally installed. One way to tell is that only a SINGLE breaker is added to the master panel. NOT a paired set like you see on Range, Drier, Water Heater, etc.

[pyoung47]

I would second the observation that it is essential to check the voltage level during the operation of the unit, since with the symptoms described, this seems the most likely culprit -- voltage drop.

Since it takes so long for the compressor to kick in, low voltage seems likely. Addition of a hardstart capacitor might help this symptom, if low voltage is not the issue.

RV AC units are not designed to be recharged. If the unit has lost refrigerant, it should be replaced.

[csamayfield55x]

wnjj wrote:

csamayfield55 wrote:
AS for the 220 volt adapter, DONT DO THAT UNLESS YOU KNOW WHAT YOU ARE DOING!!! There is a big difference between household 220 and RV 120 50 amp!!!!! If you try and plug into household 220 you will fry all sorts of stuff. Again, If you don't know electricity don't do it!!!

Chris

He said the thing that looks like 220. It's not 220, but 30A RV service. Yes, just like any RV, you can plug a camper 30A cord into a 30A RV service without an adapter. That's preferred if one is available.

OK, thanks for clarifying! I was just seeing 220 going to all his stuff and sparks flying. He obviously doesn't know about elec so I was not picking up what he was putting down

Chris

[wnjj]

Barkoff wrote:
I fired up the unit and waited for ten minutes inside the camper, and was not getting any cold air.

I turned it off went topside and inspected everything, it all looked OK. Fired it back up and went up topside again. The fan ran for at least ten minutes before all of a sudden the compressor clicked on.

To clarify here: Did the compressor not start until 10 minutes after the 2nd time you turned it on? My Mach A/C turns on pretty much immediately when I switch the t-stat to cool.

Does the compressor stay running the whole time once started or is it shutting back off?

[wnjj]

csamayfield55 wrote:
AS for the 220 volt adapter, DONT DO THAT UNLESS YOU KNOW WHAT YOU ARE DOING!!! There is a big difference between household 220 and RV 120 50 amp!!!!! If you try and plug into household 220 you will fry all sorts of stuff. Again, If you don't know electricity don't do it!!!

Chris

He said the thing that looks like 220. It's not 220, but 30A RV service. Yes, just like any RV, you can plug a camper 30A cord into a 30A RV service without an adapter. That's preferred if one is available.

[csamayfield55x]

First off, Voltage is not the same as amperage. You can have 122 volts through the smallest wire you can find but it won't run squat. You need to have the ability to do work which is what amperage is. Like the difference of putting water through a straw or a garden hose.

You need at least 20 amp potential to run the AC with any certainty. You need to find out if your compressor is trying to run or not.

AS for the 220 volt adapter, DONT DO THAT UNLESS YOU KNOW WHAT YOU ARE DOING!!! There is a big difference between household 220 and RV 120 50 amp!!!!! If you try and plug into household 220 you will fry all sorts of stuff. Again, If you don't know electricity don't do it!!!

Chris

[dave17352]

Did you check the voltage when the compressor was running. The voltage means nothing until you put a load on it. In this case the AC compressor.

[Barkoff]

First off, thank you all for the replies, good information and I plan to identify in the future, everything discussed in this thread.

I stopped on the way home and bought a heavier gauge, shorter cord. I put the Fluke on the longer lighter cord and it read 122 volts at the camper, the heavier gauge, shorter cable also read 122 volts. Doesn't that indicate it is not a problem with voltage?

I fired up the unit and waited for ten minutes inside the camper, and was not getting any cold air.

I turned it off went topside and inspected everything, it all looked OK. Fired it back up and went up topside again. The fan ran for at least ten minutes before all of a sudden the compressor clicked on.

I was up there for another ten minutes before the as somebody mentioned, the the thinner tube begin to heat up, and the bigger tube begin to cool. After ten minutes more, the bigger tube did get cold, but not icy cold.

Inside the camper I did get some cold air. Now I'm not sure if the heavier cord, helped, if the unit takes that long to get going, or maybe the thermostat is the reason for the erratic behavior..if that is erratic.

I know most parks have a 30 amp and 50 amp plug-in, can you plug a camper into the heavier connection using the cord that looks like a 220? My camper has that sort of connection, I have just always plugged into the standard 110 receptacle using an adapter.