Multiple ATS, One Generator, Kohler

[Seven-Delta-FortyOne]

I’m pretty fluent with Generac air cooled, sort of, but Kohler is set up differently.

If you have multiple ATS with one generator, do they usually run the 2-wire start circuit to each ATS, or just one?

On Generac if you run utility sense to each ATS, it can do some really funky stuff.

 

[hillbilly1]

You can parallel as many transferswitch start signals as you want. It is just a dry contact. With Generac, the generator controls the transferswitch, With Kohler, the transferswitch controls the generator. The two wire switches just tell the generator to start, and once the voltage and frequency is right, the switch transfers. If any one switch loses power, it will start the generator and transfer. If the other switches still have power, they will sit there and not transfer.

 

[Seven-Delta-FortyOne]

You can parallel as many transferswitch start signals as you want. It is just a dry contact. With Generac, the generator controls the transferswitch, With Kohler, the transferswitch controls the generator. The two wire switches just tell the generator to start, and once the voltage and frequency is right, the switch transfers. If any one switch loses power, it will start the generator and transfer. If the other switches still have power, they will sit there and not transfer.

Kinda what I thought, but you never know. Thanks for that.

 

[ATSman]

Just to add to hillbilly, typically with 1 gen and multiple ATSs the eng start pair of wires are run to the closest ATS (to gen) then daisy-chained (paralleled) to the others. Although it is rare, the pair can be wired from each ATS to gen and paralleled there. This takes more labor, conduit and wire which is why it is rarely done.
Not sure what you mean by your last sentence but with most installations (non-Generac) the utility sensing is wired to each ATS to assure that the gen will start and feed the load no matter which ATS looses power. If it is wired to only one then the other ATSs would not start the gen to feed their loads if they loose utility.

 

[hillbilly1]

Just to add to hillbilly, typically with 1 gen and multiple ATSs the eng start pair of wires are run to the closest ATS (to gen) then daisy-chained (paralleled) to the others. Although it is rare, the pair can be wired from each ATS to gen and paralleled there. This takes more labor, conduit and wire which is why it is rarely done.
Not sure what you mean by your last sentence but with most installations (non-Generac) the utility sensing is wired to each ATS to assure that the gen will start and feed the load no matter which ATS looses power. If it is wired to only one then the other ATSs would not start the gen to feed their loads if they loose utility.

With Generac, the generator controls the transferswitchs, so it only needs one utility sense, which is at the generator, which starts the generator if the generator sees power loss, not the transferswitch. Cheaper way to build.

 

[Birken Vogt]

In fact, with Generac if using multi transfer switches you CANNOT parallel the utility sensing, because if you do, you have paralleled the transfer switch utility feeders also, through 18 gauge wire and 6.3 amp fuses, which will promptly blow, (especially if you cross the phases)

With Kohler RDT, if you want to be lazy, you can hook the start contacts to the easiest switch and leave the others open. So long as the power does not go out to the other switches at different time, the first switch will start the generator, and the others will not know that they were not the ones that told the generator to start.