Transfer switch

[guschash]

I just recieved a home generator ( Generac ) and I have to buy the automatic transfer switch. But have a question about the neutral . Do I run the neutral from bottom of meter along with the line wires to the transfer switch and back to main panel. I guess what I'm asking is does the neutral get switch.

 

[LarryFine]

The neutral can, but doesn't have to be, routed through the transfer switch. It depends on the conductor routing. If the conductors enter the transfer switch through one path, and return to the panel through another, you must route the neutral with them.

If they enter and return through a single nipple or conduit, it can remain undisturbed, and you can add a neutral "jumper" conductor that is sized large enough for the generator feed; i.e., the same size as the generator's feeder neutral conductor.

In either case, if the transfer switch becomes the service's main disconnect, the green main bonding jumper between the neutral and grounding buses must remain. If there is a main disconnect ahead of the transfer switch, the jumper should be removed.

In both cases, the main panel remains, or becomes, a sub-panel, and the main bonding jumper remains out, or must be removed, and the neutrals stay, or must be, separated from the EGC's. That means that the panel feeder must be four-wire.

 

[augie47]

In 99%+ of the Generac residential installations I've seen the Neutral is not switched by the Transfer Switch. Sine you are coming off the meter the ATS must be service rated and common practice is to route your neuitral thru the ATS using it's neutral bar and install the bonding jumper (as I recall it may be provided with the switch).
Keep in mind with no switched neutral, your generator is not a SDS and must have a separate equipment ground back to the ATS.

 

[Strathead]

The neutral can, but doesn't have to be, routed through the transfer switch. It depends on the conductor routing. If the conductors enter the transfer switch through one path, and return to the panel through another, you must route the neutral with them.

If they enter and return through a single nipple or conduit, it can remain undisturbed, and you can add a neutral "jumper" conductor that is sized large enough for the generator feed; i.e., the same size as the generator's feeder neutral conductor.

In either case, if the transfer switch becomes the service's main disconnect, the green main bonding jumper between the neutral and grounding buses must remain. If there is a main disconnect ahead of the transfer switch, the jumper should be removed.

In both cases, the main panel remains, or becomes, a sub-panel, and the main bonding jumper remains out, or must be removed, and the neutrals stay, or must be, separated from the EGC's. That means that the panel feeder must be four-wire.

Doesn't the code require the neutral to be run with the hots?

 

[LarryFine]

Doesn't the code require the neutral to be run with the hots?

If the hots pass through a nipple, run through the contacts, and back through the same nipple, there is no issue. The currents will match, just like a switch loop.

On generator power, the neutral current, sharing the same nipple, would carry any imbalance and still match.