Newbie here with an introduction and questions

[Phoebe Redpath]

Hello, all!

We recently purchased a 2015 SS Agile after owning an '03 Lazy Daze Class C for quite a few years, so we are adjusting to some of the differences between our old and new rig, and we are completely new to inverters. We have a 2500 Inverter and a propane generator. We have tried to exercise the generator under load by turning on the AC, but the AC is shutting off after running for about 20 - 30 seconds. Does anyone have any advice? Thanks in advance!

 

[youngnretired]

Welcome!

A couple questions. Will the AC run while connected to shore power, and are you sure the AC's compressor is starting and not just the circulation fan? Our Cool Cat system in our 08 Roadtrek has the circulation fan start and then 20-30 seconds later the compressor kicks in. If it runs while connected to shore power, it's not a problem with the AC unit, but more inverter/generator related. You may also want to use a voltmeter and measure the output voltage from the inverter on the 120V system to make sure your inverter has the proper voltage output. IF it's low, the AC system may not start the compressor.

 

[booster]

Welcome!

A couple questions. Will the AC run while connected to shore power, and are you sure the AC's compressor is starting and not just the circulation fan? Our Cool Cat system in our 08 Roadtrek has the circulation fan start and then 20-30 seconds later the compressor kicks in. If it runs while connected to shore power, it's not a problem with the AC unit, but more inverter/generator related. You may also want to use a voltmeter and measure the output voltage from the inverter on the 120V system to make sure your inverter has the proper voltage output. IF it's low, the AC system may not start the compressor.

Yep, all of the above and would add that if it runs on shore power but not generator, it may also be the frequency which requires a slightly better meter to check. I always recommend having a plug in power monitor is you don't have a cord or mounted power monitor in the van. Bad power is getting more common every day with large amount of AC and cooking appliances in use now at campgrounds.

power quality monitor link

 

[Phoebe Redpath]

Thanks, Booster and Youngretired! This is the type of trouble-shooting advice I was hoping to find. I'll look into these and hopefully get to the root of the problem.

 

[Phoebe Redpath]

OK, the air conditioner works on shore power, so the problem seems to be the inverter/generator. One question about a 2500 watt inverter--should I set it to the power save mode or just "on" if I'm running AC? I've had it on power save, which should kick in when it senses the AC is on according to the manual, but I'm thinking I should try toggling the inverter to "on" to see if it's just the power save mode that is the issue. Someone mentioned something about harming that AC if the generator isn't keeping it running. Is that a risk?

 

[booster]

If you are able to run on shore power OK, that would appear to indicate you might have a problem with the automatic transfer switch that switches between shore power and generator.

Did you have the inverter on when the quick shutoff on generator happened? If so, you may have been actually running on the inverter when the shutdown happened because the generator power wasn't getting though the transfer switch.

To test the automatic transfer switch theory, turn off the inverter completely, and not be on shore power and see what you get.

If the AC doesn't even try to start, then try the van outlets to see if they have 110v power. If the AC does not start and outlets or dead, the transfer switch would probably be bad or the generator has the circuit breaker on it tripped.

 

[peteco]

Check your owners manual to see if the Air Conditioner can even run from the inverter. My guess is it cannot, and will only run using shore power or the generator.

 

[MarCorpsMustang]

Hello, all!

We recently purchased a 2015 SS Agile after owning an '03 Lazy Daze Class C for quite a few years, so we are adjusting to some of the differences between our old and new rig, and we are completely new to inverters. We have a 2500 Inverter and a propane generator. We have tried to exercise the generator under load by turning on the AC, but the AC is shutting off after running for about 20 - 30 seconds. Does anyone have any advice? Thanks in advance!

We made the same change from a Class C to a Sprinter-based Class B years ago. Wish we still had the Class C, but anyway . . .
Our 2014 CS Adventurous will run the A/C just fine using the propane generator. You may be on to something regarding the "auto" vs "on" setting. It's worth experimenting with both to try to find out. You may also want to try running a different high-powered appliance to see if it runs on the generator, like perhaps the microwave or plug an electric heater into a wall outlet.
In our rig if we exceed the capacity of the generator the generator goes into "save" mode by tripping a breaker that disconnects power from it. It sounds like your generator continues to run but the A/C shuts itself off. Perhaps check all the filters in and around the A/C and check for debris on the outside, all of which may cause it to overheat and turn itself off due to an overheating condition.

 

[OregonTrader]

We have a 2015 Agile as well. There are different versions that have different electrical configurations. We have the version with a 3000W inverter and 2 AGM batteries. The air conditioner will run fine with the inverter, but it won't last long without the generator running. Two things come to mind:

1. We've experienced odd behavior from our A/C when the thermostat is not set to Fan > Auto. To check, switch the thermostat to fan mode and then select Auto (Au). You can then with set it back to heat, cold or off.
2. We were told by Roadtrek not to use the inverter in automatic (Power saver auto). It should be either on or off. (And you should leave the inverter off unless you are using an appliance or the A/C that requires 120 volts AC, as the inverter drains the battery pretty quickly even if it's only powering itself).

We love our Agile, having traveled over 80,000 miles since we bought it slightly used almost 10 years ago. Enjoy!

 

[engnrsrule]

Like Booster (who is a primo smart man on RV electric) I was wondering if you were actually running off the inverter. As for shore tie, the AC may not run if you are hooked to a 15a household outlet. But your propane generator should carry the AC no problem. You may want to confirm the how water heater is not also running on electric. My AC calls for 20a. I doubt your inverter will run the AC, or at least not for very long. Start up voltage is the killer with AC. Once you verify what power source it's actually trying to run, you may want to consider adding a Soft Start to the AC, which lowers the starting current draw.

 

[bused]

I don't know if you are reading a similar conversation that I posted on the Airstream Forum. (Problem with A/C Operation from 2.4 KW Propane Generator)

The results are IDENTICAL ! The components are similar. I listed details of my components in the above link. In summary 2.4 KW Cummin propane generator, Victron 3000 MultiPlus inverter, and a Dometic Penguin A/C with Micro-Air EasyStart.

I am speculating, it is a system problem where 2 (or more) components are in conflict.

Lets identify the differences and common components.

Thanks,
Ed Roelle
Sarasota, FL

 

[booster]

There is a lot more information there, and here is the problem description as you stated there. I just read it.

Problem Description
- 2.4 kw Generator operates A/C fan (which continues to run), but the compressor stops intermittently within 1-4 minutes (A/C load 14 amps/fan 3 amps alone, continuous 114 volts)
- A/C operates from generator properly when wired directly from the generator (eliminating transfer switch, inverter, breakers, etc.)
- A/C works great on 30 Amp Shore Power going through total system transfer switch, inverter, etc.
- A/C operates great on inverter.
- Microwave operates fine through the normal system while operating on the generator with a similar 13 amp load

I think that this is probably lending support to the bad transfer switch theory

The fact that the genny runs the AC fine with transfer switch is bypassed in the key, IMO.

What I think may be happening is confusing but does make sense, at least the me

The transfer switch is shore power first priority and if it fails that is where it will always be. Everything runs great when on shore power on your description, including the AC.

When on generator, the microwave works but the AC only kinda works. The fan runs OK, but keeps cycling with compressor on. That may mean it just can't handle reduced amps from some source.

The short recycling to on time is typical of an AC unit if it shuts down for some reason as it is a recycle timer to prevent tying to start against built up back pressure in the compressor.

The microwave runs OK on generator, but is it running on the generator or inverter? That is going to be the key to all of this. My guess it is running of the inverter and it keeps running because it doesn't have the huge surge of a compressor starting like the AC. The AC is trying to run on inverter but it can't supply enough power to restart the compressor, maybe because of low batteries, maybe AC has a bad start capacitor, or some other reason. Most likely low batteries.

You have gotten to transfer switch, it appears, so time to get a clamp on ammeter onto the wire into it from the genny and then out from the transfer switch. My guess again would be there won't be any.

The confirmation test you might want to run would be to try the microwave with neither shore or generator power. If it runs OK you know it is on inverter as it is the only power. Then try the AC unit the same way and see if the fan runs and compressor won't run and you would have your answer. Change the transfer switch out if it behaves that way.

With a system as you describe there is probably an automatic transfer switch at the AC input point from shore and generator wired shore priority.

To be able to use an inverter with the single automatic transfer switch, you need a second automatic transfer switch and in the Multiplus literature it says that is inside the Multiplus.

With this system, the inverter will not but out power unless there is no AC power to the Multiplus so if the first transfer switch fails to switch to generator throughput, the Mulitplus turns on the inverter.

It should be pretty easy to look for AC power at the input to the Multiplus when on shore and generator to see what is really going on.

 

[Phoebe Redpath]

Thanks, everyone, for the suggestions! I've finally gotten a chance after the holidays to do some trouble shooting, and I'm pretty certain it's the connection between the generator and the air conditioner. Here's a run down:

--everything works ok on shore power
--with the generator on but inverter off, neither microwave nor generator will even start
--with the generator on and inverter on (not auto), the microwave works and the AC turns on but doesn't stay on for longer than a couple of minutes. I think the theory is correct that the inverter might have been running the AC, not the genny, and that it's a transfer switch problem.

I'll let you know if I find out otherwise.

Thanks again!