Start delay on Dometic air conditioner

Turn it off.

You should not have any extra load turned on when starting a generator, especially not both AC's. Start the gen set and let it run a few minutes before turning on the first AC and then after a few minutes turn the second AC on. Give it a try.

Groover wrote:
My coach has two Dometic AC units and a 6,000 watt Onan quiet diesel genset. If both units are enabled when the generator is started they both hit the generator at the same time which overloads it and forces it off line and the cycle repeats every time the generator resets.

Does anyone know how to change the delay in one of the AC units so that the generator has time to recover from the first one before the second one hits it with a starting load?

This is a PERFECT example of a RV'er that will have Transfer switch problems in the future. He is transferring current with a large load. To the OP, STOP doing this. It will burn out your transfer box and also the points in the box will get pitted. The delay on a Dometic is about 2 minutes 45 seconds. The timer starts when original 12 volt power is supplied. It is rare that 2 or 3 AC units will be on the same time sequence. But, regardless, what you are doing will cause problems in the future. To change the timer, just turn one AC off for 1 minute and then turn back on. That should change the timer for that AC. Doug

Part of why I bought a camper with an air condition is to keep the coach cool when I am not around. This came in very handy at Yellowstone since I had pets with me that were not allowed on trails and had to be left in the coach most of the day. The automatic generator start even has a setting to start according to inside temperature so this use is apparently anticipated and very handy.

Also, the less technically oriented members of my family insist on trying to run things even when they don't grasp certain concepts or the symptoms of the problems they create. I need to make it idiot proof.

My ac's have a control board that controls the delays.

Groover wrote:
My coach has two Dometic AC units and a 6,000 watt Onan quiet diesel genset. If both units are enabled when the generator is started they both hit the generator at the same time which overloads it and forces it off line and the cycle repeats every time the generator resets.

Does anyone know how to change the delay in one of the AC units so that the generator has time to recover from the first one before the second one hits it with a starting load?

I have not a clue what you have, what year, an EMS or not, or much else, but we have no problem with this in our old 30amp coach, even if we're not plugging in our rear air separately at the shore pedestal.
As for a stupid transfer sw. that could fail, we have not and plug into the genset outlet when storing the cord away, right next to it. I mean how difficult is this for a no brainer in coach engineering. Maybe I'm just missing something here.
As for your original question, I'd probably break the circuit on the rear air and install a time delay on pickup relay in the circuit.

It is a 2013 coach. I feel like changing the delay on one unit be 10 seconds would solve the problem for me. The coach has a 2,000 watt inverter that is supposed to be able to handle demand spikes when plugged in to limited shore power. If I can figure out how to make that help the generator that would solve the problem. I am not familiar with external time delay circuits but I will study on that and see what I can come with.

The AC units are Penguin 13.5K 2-speed rotary 2013 models. The inverter is a Magnum ME series 2012 wtith ME-RC remote control and ME-AGS-N automatic start.

The inverter seems to be sized to run the microwave but the oven makes bad noises on inverter power so I am afraid to use it very much unless the gen set is running or I am plugged in. Does anyone know if I am being too cautious here? If I want to run it more than just a few seconds I would want to have the main engine running so I am not hitting the batteries too hard but I hate to crank the generator for a 60 second run to warm up some tea on the road.

Penguin 13.5K 2-speed rotary 2013 models

OK, 2 speed rotary. WHAT does that mean? Do you have controls in the roof (rotary knob controls)? If so, there is NO time delay on the compressors. Time delay is only on wall tstat model RV AC units. Doug

There is a built in delay in the AC units that has nothing to do with the generator or shore power. This is to prevent the AC units from cycling the compressor on and off with a power surge. In other words, if you lose power and then it comes back on in a few seconds, your AC compressor will not come on until after the delay.
When you generator starts, IT IS NOT starting with a high load from the AC units since the compressor will not be coming on right away. Their fan will start first, which is a minimal load, and then the compressor will kick on a short time later. This is the normal cycle for an AC unit. It would be extremely odd if both AC units tried to kick on at exactly the same time, even if you have a dual zone thermostat.
Your generator should start and get up to full output power BEFORE the transfer switch kicks in and provides power to all systems in your coach. At that point, your generator should be able to handle the load from the AC units with no problem. I suspect that you have a problem in the generator output adjustment that it preventing the generator from maintaining the correct power when a load is applied. If the voltage drops too low, your Energy Management System will kick things offline.