GordonThree wrote:
CoeyCoey wrote:
I don't think I will need one of those. I am simply going to have a relay that closes when shore power is lost and tells the generator to start. Then the ATS will kick over to generator power.
A simple relay is not sufficient. you'll likely damage your generator, inverter, air conditioner, etc.
You AT LEAST need a time delay relay, one that for example waits to energize 2 minutes after power is lost, and stays energized at least fifteen - thirty minutes after utility power is restored.
The Magnum AGS isn't very expensive, and likely Victron makes a similar unit for their inverter. Far easier than trying to DIY some sort of time delay circuit.
Time delay, yes, however the time you quoted however may not be true for ALL ATS. A COMMERCIAL/INDUSTRIAL ATS with automatic gen switchover perhaps you MIGHT see such long delays in switchover and 15-20 minutes of gen run after commercial power is restored.
In reality that long gen run after commercial power restored is to allow the gen to operate WITHOUT A LOAD in a cool down cycle or allow for intermittent utility power . Even in this situation the power would have been transferred SECONDS after utility power was restored.
In reality, the ATS should only switchover at the ZERO switching point of the incoming sinewaves, just takes a few seconds for both sources to present this opportunity.
Some ATS do monitor the zero switching and some do not.
RV ATS just uses a small time delay to allow gen to come up to voltage and stabilize..
Per Progressive Dynamics 30A RV ATS
HERE..
"Description of Operation
When the shore power is applied the relay is at rest and power is transferred to the panel.
When Generator power is applied there is a 20-45 second delay and then the relay activates transferring Generator power to the panel.
If shore power returns while the Gen power is present nothing will happen. When the Gen power is removed the relay will drop out and allow the shore side to supply power.
Generator overrides shore power. "As far as the OPs request, I suspect you will have to "bake your own" custom gen start, ATS and gen shut down. You would have to add in lockouts (failsafes) in case gen fails to start within x amount of tries, protections for gen malfunctions like too high voltage, to low voltage, out of spec frequency, overloads and so on..
Most auto start/ATS systems are custom designed for a specific brand of BUILT IN gen and will have a lot of failsafes diagnostics baked into it..
I suspect at the end of the day, this is not your typically DIY project and will be more difficult and not to mention more expensive that it will be worth..
Perhaps try a different approach, you could go with a smart home T stat (in this use would not need to be connected to heating or cooling system, just needs some power), a mobile hotspot all run from your 12V system, setup the T stat to report the temp.. The if the power fails and your RV starts getting warmer then the smart T stat can send you an alert to your phone to let you know it is hotter than your preset..
RV should stay at a fairy reasonable temp for an hr or so without power provided you have it set in some shady spot.
