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Topic: Generator Auto-start with AC (Read 706 times) previous topic - next topic

Generator Auto-start with AC

Quote from: Tommy D –
Jack, did you change the low voltage cutoff only on your inverter/charger?  Did you adjust your generator auto start?  I will have to check but I think my inverter is set at 10.5 also but sometimes my Generator will kick on if I run the microwave for 5+ minutes.
I didn't want to hijack someone else's battery thread so I'm asking here. We're going to make a taco run into Los Algodones this weekend, leaving the coach on the US side. I am somewhat concerned about leaving the dogs in the rig for 3-4 hours in 74 + sunny weather. Can I leave the genny in auto-start mode, the inverter on, and one AC set? Does the genny also auto-off once a certain voltage is reached?

I'm guessing these rigs are well enough insulated that the pups would be fine without the AC but it's got me thinking

1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Generator Auto-start with AC

Reply #1 –
The OEM generator autostart, unless it's been replaced with a much newer system, will not fire up until batteries get low.  It won't care that your roof A/C is set on and your roof A/C isn't powered from the inverter.

There are newer systems that can tie an autostart to a roof a/c, but they would be a recent aftermarket upgrade and not the OEM equipment.

Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Generator Auto-start with AC

Reply #2 –
Quote from: Michelle –
roof A/C isn't powered from the inverter.
Ah, there's the lynch pin then. Thank you... makes sense.
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Generator Auto-start with AC

Reply #3 –
Open front drivers window and turn on the fan above the stove that is on a thermostat might work

2000 GV320 4010 build #5712  2019-?
1999 Bounder 2000-2008
Bardstown, KY
🥃The Bourbon Capital of the World🥃

Re: Generator Auto-start with AC

Reply #4 –
On our 2014 if you have auto-start enacted.  The generator will start if the AC's requiring to come on or if the voltage of the battery gets below a set voltage.

You can test to see if yours works that way by turning on the auto start and then having the thermostat call for AC from one of the units.  You then will be able to see if the auto start will start the generator if the thermostat calls for cooling.
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Generator Auto-start with AC

Reply #5 –
74, open windows and let the fans draw pups will be fine.
Hans & Marjet
1995 U300 "Ben" (#4719)
3176B Cat,4060HD,Jake
SKP#139131
Motorcade#17579
2006 Honda Element (towed)

Re: Generator Auto-start with AC

Reply #6 –
Quote from: turbojack –
On our 2014 if you have auto-start enacted.  The generator will start if the AC's requiring to come on or if the voltage of the battery gets below a set voltage.

The OEM auto gen start on Elliot's coach would not have that capability.  It would only come on with a low voltage threshhold, but not because the a/c needs to run.

Newer coaches like your IH and a Realm might, as they are much more sophisticated as is the control circuitry, but not the U-series coaches unless battery monitor, generator control, etc. was upgraded by a previous owner.

In an OEM setup of Elliot's coach's era, just having the roof a/c set to come on will not pull down the batteries to a low enough voltage to start the generator (unless there's a problem with the batteries).  The roof a/c thermostat will simply see there is no 120VAC power to the roof air and either sit there doing nothing or display an error code.  Additionally, once the battery charge meets the sensor's upper trip point, the generator shuts off, which would shut off the a/c unit due to no 120 VAC.

https://www.foreforums.com/index.php?action=media;sa=media;in=3323
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Generator Auto-start with AC

Reply #7 –
You could just start the generator and run the air then you would not have to be concerned about it. The generator only uses about 1/2 gallon per hour
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Generator Auto-start with AC

Reply #8 –
So I had Gilles at OffTheGridRVs (he's a member here) do my solar install and I'm beyond tickled with it. He once again knocked the ball out of the park.

One of the things he did is relocate my living room AC unit to the circuit that's powered by the inverter. I still need to adjust the autostart voltage for the genny but once I do I'll be able to leave the AC on and it'll draw down the batteries to a certain voltage, which will in turn kick the genny on to charge them back up.

I don't know that it'll ever be necessary though. I checked my BMS while the microwave was running and it said I had 4.5 hours of juice left while at an 82% charge  :))
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.