JBarca wrote:



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.

***Link Removed***

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

CA Traveler wrote:

55V on startup? Sounds like the gen can't handle the surge. Even 95V is low.

What is the AC voltage and amps on shore power?

Mdk0420 wrote:



It is a ducted system. Do these AC units just happen to draw a ton of current when starting?

It's always been hit or miss since I got the generator. I would say it starts about 90% of the time unless I purposely short cycle it then I can pretty consistently trip it.

I did test both the motor starting Capacity and the main capacitor and they are within spec. I tested the coils as well to make sure there aren't any resistances in the coils and all seems good. The unit does work most or the time after all, and it is cold. It's just unreliable.

Mdk0420 wrote:



It seems to be a common problem with all generators due to the need to ramp up however from the tests I've seen the honda only drops to 95v for a few seconds. Then again the test I saw was with harbor freight testing us8ng a kill a watt meter and that thing is pretty slow and inaccurate.

To run my tests I plugged in the kill a watt meter first then a line splitter and used my clamp over the line splitter to get amp readings while using the ports on the line splitter to test voltages. The kill a watt meter helped me see wattage readings real time within some sort of accuracy. The amps and volts I did off my meter because the kill a watt doesn't hold min/max but also doesn't react quick enough to get the voltage drops. It was saying voltage drop was closer to 105v but i know that's not accurate when running the min setting on my meter I got a 55v reading. Testing shows that it ramps up to 95v almost instantly maybe a second or two before it gets back to 120v.

I know 95v is normal because of honda inverter tests I've seen. Those 2200i's can actually start ACs but my 4500w generator can't and it's kind of disappointing lol.

It's also weird that only sometimes it maxes out the generator almost like a motor locked up. Other times it starts up just fine.

Preload doesn't seem to help because it trips sometimes when the AC fan is still running but once the compressor kicks in it trips. It's very random and I can tell when it happens while outside because the generator will Rev all the way up for a few seconds and eventually trip

Mdk0420 wrote:


Thanks for the info. I have a feeling it's a combination of both issues. My generator might have a hard time handling hard spikes that max it out at the same time this compressor might just be very hungry for amps.

I think I will get a soft start because just about any AC I have or in the future would get, would be a nice addition to have just to make the components last longer if nothing else.

Do you recommend a soft start brand? I have been looking at then and don't know which ones would be good or not

JBarca wrote:



I just saw this response as I was typing when it came in.

OK, there is something else that may be going on. Your statement in blue turned up a few thoughts. Since you are running on a genny, you are boondocking off-grid, right?

Unless you or someone changed it, your 2003 Sunline is on the older American Enterprises power converter or the Centurion. What size battery bank do you have, and what guidelines do you follow when to plug in and charge the batteries? Those older power converters did not have a boost mode. The point is, what else is going in the camper that eats into 120 VAC power?

The fridge is going to take 325 watts 120 VAC unless you force it to gas mode only. The water heater will pull 1,400 watts if the AC elements is on, and the power converter, well, it's a wild card pending on how drawn down your battery is. Those 3 power draws can all be going on in the background and you not know it unless you force a test with them all off. For a test, turn the power converter breaker off, (Sunline used to put the power converter on the general purpose circuit) the fridge, and the water heater off, (yes your 2003 can have an electric element heater, the power switch is on the back of the heater itself, not on the tank panel. ) Then connect the battery, and it will run the 12 VDC to run the AC unit controls. If the genny works consistently, then other loads in the camper may be randomly adding up against you.