AC tripping generator

[Mdk0420]

Hey all. I seem to be having some AC issues unfortunately. I ran some diagnostics but I haven't been able to figure out the problem.

I'm using a Westinghouse igen4500df generator. This should be more than enough to start an AC however it's hit or miss. Sometimes it starts up, other times it just hums until the generator trips its overload protection.

I've tested the resistance of my compressor coils and they show no resistance. My capacitors are very close to their ratings (both within 2%). Motor starter is on the low end kf its 43-52 rating at 43.8 but shouldn't be causing the issue if it's within range.

On the generator side I've ran a few test and need to run a bit more because I forgot some data. But what I have so far is here:

A successful startup did a draw of 28-30 amps.

An unsuccessful startup maxes out the generator at 48 amps but the voltage was down to 95v during the heavy draw period. After about 5 seconds it trips the overload

The generators low voltage goes all the way down to 55v on initial heavy draw and comes back to 95v in under a second and back to 120v or so within 2 seconds except when it has the unsuccessful start. It doesn't get passed 95v and 48 amps.

I'm measuring from the start of the generator line using true rms equipment so these voltages are probably lower at the compressor.

The fan motor spins freely. I did not check the refrigerant. It does get nice and cold when on.

I do want to get a soft start but I'm still baffled that a 4500 watt generator can't start a single AC system. I run my 15k BTU AC uni in my shed no problem.

Any suggestions on what else to look at? Is this somehow normal for a unit without a soft start? Are Westinghouse generators just junk?

[valhalla360]

You might try plugging someone else's trailer into the generator and see if it will start the air/con.

[bgum]

I think it's time for a new AC or at the very least new capacitors.

[JBarca]

Mdk0420 wrote:
I should've specified. This is bare bones. A few miliamp draw probably from something like the gas detector or something. Fridge is off along with everything else. No lights. I have a high and low setting for the fan speed. When I got the 28 amps I was on low. When I got 30 amps I was on high. But that couldve been a coincidence. I did not record the amp draw Under normal conditions yet. I was more focused on the high draw when I did my tests.

This is a single unit. I believe it's a 13500 btu unit. Didn't lookup the model number though. It's a 2003 sunline 27ft. I assume the AC is original since when pulling the cover off it has a lot or cracks in it from being brittle (I may of caused more cracks pulling it off lol)

Hi,

I am very familiar with the Sunline campers. A 2003 Sunline, 27 ft would most likely have 13.5K btu AC on it unless someone upgraded it.

See this post where I did some amp testing on my Sunline. Before on the 13.5 K btu unit and then on the 15 K btu unit with the soft start.

http://forums.goodsamclub.com/index.cfm/fuseaction/thread/tid/30390081/gotomsg/30391084.cfm#30391084...

On my coil cleaned 13.5K btu unit, with the power converter running on a charged battery, no other 120 VAC on in the camper, but the AC fan was on before the compressor kicked on, and I got 37 amps in rush.

As I was typing this, something dawned on me, what model is your Sunline? Or, more importantly, do you have a ducted system, meaning multiple ceiling ducts, OR do you have no ducts and all the cold air comes out of the center area of the AC unit inside? (a non-ducted AC) The control systems are different for the ducted and non-ducted.

Hmm, have you ever run the AC on your genny successfully in the past?

I can see maybe 2 things giving you an issue if you are on the ducted AC system.

Your compressor starting capacitors may be weak on the older motor, (there should be 2 caps in your AC junction box up the roof if it is the original)

Your genny does not have much surge spike forgiveness. Again this comes back to, did that genny ever run the AC unit well or are you just trying it now for the first time?

Dirty coils on the AC will pull a little more current, but not that should stop your genny from working.

Hope this helps

John

[Mdk0420]

valhalla360 wrote:
Shouldn't need a soft start with a 4500w generator. My best guess is the water heater is on electric and the battery is low so the charger is putting out max charge...that may be enough to push it over the edge.

The 12v battery is disconnected. I have it charging for when we go on our vacation in 2 weeks.

The hot water heater is off. I don't think mine has an electric option but I have no load amps of a few miliamps even if it did. I've always operated my hot water from a button on my control panel and it runs propane to heat it up but that switch is off

[valhalla360]

Shouldn't need a soft start with a 4500w generator. My best guess is the water heater is on electric and the battery is low so the charger is putting out max charge...that may be enough to push it over the edge.

[Mdk0420]

I should've specified. This is bare bones. A few miliamp draw probably from something like the gas detector or something. Fridge is off along with everything else. No lights. I have a high and low setting for the fan speed. When I got the 28 amps I was on low. When I got 30 amps I was on high. But that couldve been a coincidence. I did not record the amp draw Under normal conditions yet. I was more focused on the high draw when I did my tests.

This is a single unit. I believe it's a 13500 btu unit. Didn't lookup the model number though. It's a 2003 sunline 27ft. I assume the AC is original since when pulling the cover off it has a lot or cracks in it from being brittle (I may of caused more cracks pulling it off lol)

[bgum]

What is size and age of your airconditioner? What other items are drawing on the genny? Water heater
Converter fridge heat strip you name it
That genny should have no problem starting a 15000btu AC.

[Fulltimers]

Make sure EVERYTHING else in the RV is OFF. I know I was running my 2 ACs off 30 amps once when suddenly the breaker tripped. Turns out the Refrigerator kicked in.