AGS/Generator Turning On and Off by Itself

[dxg0001]

Please see below where the answers I got from the Magnum Tech differ from your opinion:

Originally Posted by RVinsurance

I would rethink the assumption that just because the AC unit happens to be 'running' when exterior power is lost, that the AGS would 'automatically' and immediately turn on the generator, and somehow run it until [the coach] is out of fuel(everyone's real fear).

Here's why:
The AGS is designed to ONLY crank the generator in TWO scenarios: Voltage and/or Temp

If you are plugged into external power(shore power), and the power is 'lost'(brown out, etc), then nothing happens other than the INVERTER would take over 120v power, IF you have the Inverter 'ON' when this happens(or in 'Search Watts' mode, but that's a different discussion for another time), and you would only LOSE the air conditioner, water heater(elec), and any other 'direct' 120v items that do not run thru the inverter breaker.

WHEN power is lost, and THEN the battery Volts eventually drop to a low enough number, at or below the 'Volts' setting for the AGS for more than 2 continuous minutes, THEN the AGS would start the generator. IF the air conditioner is 'on', it would also power UP after the generator reaches it's initial full 120v power output. Your Inverter panel should also then show 'Charging' if you have your Charger 'On'.

and/or

WHEN power is lost, and THEN the Temperature increase to at or above the AGS 'TEMP' setting, it would start the generator to then run the air conditioner(s). My Ventana and from what I understand most newer Newmar models do not have a temperature sensor connected. Instead Newmar installs an interface to the thermostat. The AGS is not set to a temperature but rather to "EXT" which monitors a 12V signal coming from the thermostat. That signal is active anytime the thermostat asks for A?C to be on. The tech told me that the AGS will start the generator immediately if that signal is on and if the inverter uses power.

Now, no matter WHICH situation is what triggers the AGS, the 'RUN TIME' setting will determine how long it will run the generator, but ONLY until either that time has elapsed, or the fuel level is at 1/4 tank, per the Magnum MANUAL. In neither case will the coach's fuel system be run 'dry'. The AGS really doesn't 'care' whether the coach has lost external power or not, it just does it's job no matter.

and you're right about the 'external power restoration' not affecting the generator - the generator is not 'aware' of external power, since the ATS(auto transfer switch) 'defaults' to the generator, even when external power is available. This is why the 'RUN TIME' feature is important. If you have it set too long, it 'could' run a very long time even if external power has been restored.


According to the tech, "RUN TIME" is only used if the generator was started due to battery voltage. If it was started because of temperature it will run until the A/C shuts off or the tank goes down to 25%.

travel, AGS, enjoy! 84,000 miles in almost 4 years... Magnum is a great product!

I don't disagree but it appears this feature hasn't been fully implemented. Who want's to run their generator (potentially) for hours when it is not really needed?

[CoreyinWP]

I am new to Newmar and the magnum AGS. It seems to me if wanting this feature to protect our pets, and at the same time not having it go on as soon as there is a short interruption in power that the non-thermostatic control would be better. For example, if I left the coach at 72 on the thermostat with pup in coach, if I could set the AGS to come on at 75, then if there was a short term power outage, the AGS would not kick on ( short of low voltage). It would act as a failsafe without going on at the moment you lost power in hot weather. Is my thinking correct? Wouldn't that be preferable?

[C.Martin]

Originally Posted by CoreyinWP

I am new to Newmar and the magnum AGS. It seems to me if wanting this feature to protect our pets, and at the same time not having it go on as soon as there is a short interruption in power that the non-thermostatic control would be better. For example, if I left the coach at 72 on the thermostat with pup in coach, if I could set the AGS to come on at 75, then if there was a short term power outage, the AGS would not kick on ( short of low voltage). It would act as a failsafe without going on at the moment you lost power in hot weather. Is my thinking correct? Wouldn't that be preferable?

You are trying to make it an eco mode? I don’t think the 3 degree spread is worth messing up a good thing.

It works fantastic the way they have it. We enable it whenever we camp with our dogs. And when we dry camped at the Albuquerque Baloon Fiesta and FMCA Rally in Perry, GA...we enabled it to give us coordinated generator running based on actual demand. It is phenomenal.

We do have a separate alarm to tell us when the power is out or temperature gets too warm inside. It’s a great backup in case I forgot to enable AGS...both A/C units loose refrigerant...or the AGS doesn’t function for some reason.

If you want to mess with the AGS functions to improve on them...then installing a ME-BMK battery monitor AND ME-ARC Advanced Remote is what I recommend. Instead of Voltage...you can use actual State of Charge. It also can be programmed to run during specific times of the day, set up an excercise cycle to,automatically excercise the generator, and even do a battery top up calculated to boost your bank before quiet time hours begin. More management tools than the two the basic installation grants you.