Standby Generator overnight shutdown procedure

[MrTomas]

I have a Generac standby generator and a Generac ATS. In the case of a prolonged power outage, I would like to shut down the generator overnight. The procedure in the user manual is to shut off the main service disconnect breaker, then the generator disconnect breaker, and so on. My question is this.

Why leave the main service disconnect breaker (the one on the transfer switch) off overnight? The power may return overnight. I see no safety reason to do this. Am I missing something here?

 

[Barbqranch]

On my Kohler, I just put a switch in the low voltage line from the transfer switch that tells the generator to run.

 

[qcroanoke]

I have a Generac standby generator and a Generac ATS. In the case of a prolonged power outage, I would like to shut down the generator overnight. The procedure in the user manual is to shut off the main service disconnect breaker, then the generator disconnect breaker, and so on. My question is this.

Why leave the main service disconnect breaker (the one on the transfer switch) off overnight? The power may return overnight. I see no safety reason to do this. Am I missing something here?

There is no reason to turn off the main disconnect.
Unless you would happen to be working in the switch when power returns and then it will transfer to it and could be dangerous to someone working in the switch.
I can see turning off both sources in that scenario but not just because you shut down the generator.

 

[MrTomas]

There is no reason to turn off the main disconnect.
Unless you would happen to be working in the switch when power returns and then it will transfer to it and could be dangerous to someone working in the switch.
I can see turning off both sources in that scenario but not just because you shut down the generator.

As the homeowner I am only responding to a power outage. I want to power down the generator at night and let the grid power me when its back.

 

[LarryFine]

Can't you just set the generator's "on/off/auto" control switch to "off"?

The ATS should still switch back to utility power when it's restored.

 

[MrTomas]

Yes, Larry, that was my conclusion too.

 

[MrTomas]

and yet... death

 

[qcroanoke]

View attachment 2574920
and yet... death

That's known as CYA....

 

[MrTomas]

I just got it now. The generator instructions above cannot assume there is an ATS. Duh.

 

[qcroanoke]

Can't you just set the generator's "on/off/auto" control switch to "off"?

The ATS should still switch back to utility power when it's restored.

It may have an audible alarm if you take it out of auto and leave it in off.
I know some of the bigger Generacs do.

 

[Hv&Lv]

Can't you just set the generator's "on/off/auto" control switch to "off"?

The ATS should still switch back to utility power when it's restored.

The problem with that is without turning off the breaker,( I turn off the breaker in the generator only. Leave main alone) the generator shuts down with lower and lower frequency and voltage during the shutdown. And I’m not depending on the generac ATS to trip to N or Utility.

 

[Seven-Delta-FortyOne]

The best way to shut down an air cooled home standby Generac while under load is, switch the breaker on the gen to off, let the unit run for about 2 minutes, and then push the off button.

Remember to go back and push auto after power comes on, or it won’t transfer automatically.

Manufacturers like to complicate things sometimes.

 

[MrTomas]

Thanks, y'all. For completeness, here are the steps in the owner's manual:

1. Set utility MLCB to OFF (OPEN).
2. Set generator MLCB (generator disconnect) to OFF (OPEN).
3. Allow generator to run for cool-down for approximately one minute.
4. Set generator to OFF at the controller.
5. Remove 7.5A fuse from controller.

Step 1. is the step of my original question, which we established is not necessary. I am guessing step 5. is to remove power from the controller and save the battery. Any idea how long it would take the battery to drain if the controller fuse is not removed? Has to be a pretty low power draw.

 

[qcroanoke]

Thanks, y'all. For completeness, here are the steps in the owner's manual:

1. Set utility MLCB to OFF (OPEN).
2. Set generator MLCB (generator disconnect) to OFF (OPEN).
3. Allow generator to run for cool-down for approximately one minute.
4. Set generator to OFF at the controller.
5. Remove 7.5A fuse from controller.

Step 1. is the step of my original question, which we established is not necessary. I am guessing step 5. is to remove power from the controller and save the battery. Any idea how long it would take the battery to drain if the controller fuse is not removed? Has to be a pretty low power draw.

I wouldnt do step 5 either.

 

[MrTomas]

I wouldnt do step 5 either.

And for what reason?

 

[qcroanoke]

I wouldnt do step 5 either.

Steps 1 through 4 will effectively shut the generator down and prevent it from starting automatically. Step 5 is just making really sure and losing the fuse is a real possibility and then you're dead in the water.

 

[Seven-Delta-FortyOne]

You are correct that without utility power and without the generator running, you have no battery charger.

If you are just shutting it down overnight you should be fine. Any longer and I would pull the fuse. You will get a “battery charger missing” error code which you will have to clear.

 

[LarryFine]

Pulling the fuse also means resetting the exercise timer.