Onan AGS temperature control

[newmarokie]

I think nearly every post I have made has started with something to the effect "still trying to figure the Dutch Star out". Well, here it is again. When trying to set the automatic generator start based on temperature I am having zero luck. If I even really have that capability, how does the Magnum system get a temperature point for operation? I have adjusted the set point and run time both to no avail. Once it starts, it never shuts itself off. I've tried manual and auto settings as well. I have successfully used voltage setting for auto on/off function. This is not a critical problem I am just trying figure out how it should work. We are moderate temps right now and we should be able to let the generator go quiet at night. I can shut the generator down manually when we go to bed, but if the DW gets hot in the middle of the night, well everybody knows how that is going to work out.

 

[Kevin D Pem]

Think the generator start function is based on battery SOC!

Enforced quit times could have you facing enforcement officers in the middle of the night!!!

 

[Neal]

AGS setting for the ext temp or whatever it’s called simply means it knows when your AC wants to start but it doesn’t have 50A power. The gen will then start so the AC can run. It will also turn off when the AC’s are off until setpoint is reached.

You can test this by turning off shore power and commanding your AC to run by lowering the setpoint

Also of note. If something starts the GEN it should be what stops it or you’ll get a fault. If AGS starts it then AGS needs to be what stops it.

 

[newmarokie]

Kevin, as of yet, I haven't parked where I would have to worry about an enforcement officer, but thanks for the reminder. I have used the restricted run times and that function seems to work OK. But with that funcion turned off and the temp function turned on, The generator never shuts off. We just got home and I will play with it some more.

 

[newmarokie]

OK. First, the temp start function is working as long as the thermostat is set to cool, not auto. Second, if you shut the system down like Neil said and get a fault, you have to go in and turn the autostart to off, then back on to clear the fault. Going in and clearing the fault history will not do it. All is good in the auto cool world.

 

[Chuggs]

Newmar wired the Magnum AGS system well for this. The problem, which Neal addressed is knowing that you have to 1) have it the AGS Temp=ext. This means it isn’t looking for a thermocouple reading…it is looking for an external trigger. What external trigger??? Well…you know the control circuit boards each of your Dometic Rooftop A/C units have? There is one more of those mounted near the ME-AGS. The control board down ther has only one dip switch selected…AGS. The main CCC2 thermostat inside the coach has to be ON with at least one zone on COOL, with a set point. Your thermostat runs off DC power. When the set point is reached…the A/C wants to start but doesn’t have a source of AC power…that triggers the control board downstairs to close a relay (run command) which is sent via a little Pigtail device (ME-PT2) to the ME-AGS…and if you have the Aagas programmed and Armed with Temp=ext. it will go thru it’s paces.

The paces all depend on software versions. Mine sheds loads, starts genny, sheds the loads controlled by the electrical mgmt system, the generator connects to the AC distribution box thru the automatic transfer switch…after the warmup period is over the loads begin to reinstate and that’s when you’ll get air conditioning. The main difference I have heard of, are some early revisions run for the run time, then check to see if A/C is needed or not..and will either trigger another run time, or shut down. My 2016 just sheds loads…lets generator go thru a cool down, then shuts the generator back off, until needed again.

I think it’s a good idea to set up a test and run thru the steps and get squared away. You don’t want to be experimenting when you need to step away on a hot summer day with pets locked in the coach…having not built any confidence in the system. When we had our pets…we armed the AGS even with shore power available…so it would come on in the event shore power got knocked out and A/C was needed. Of course we had an alarm notification system to call us if it got hot or power was out as a backup to the backup.

Hope your trail runs go smoothly!

 

[newmarokie]

Had an interesting weekend. Plugged in to the pedestal and surge protector said "no, this is bad juju and I will not let you access it". The AGS worked flawlessly on voltage and temp settings. The voltage would come up a bit at night after all the ACs around started turning off and the surge guard would open up the circuit and let AC power in until about 10:30 in the morning. The voltage would dip and the generator would fire up and run virtually all day. Less than five miles from the campsite the generator would fire up off of the temperature setting.