The final step in this installation project is to complete the wiring that sends power from the generator to the house panel through the automatic transfer switch. When I wired the garage I installed a 1" conduit from a box in the garage wall into the basement utility area for use with a generator. Our original plans for a generator was to use an outlet in the box and send power to a manual transfer switch. Since we are now going with this automatic system I removed the manual switch and installed the enclosure for the automatic unit. I used a fish tape to pull the three #6 copper conductors from the box in the garage.

Wall box in garage

Sandy guided the wires into the box in the garage while I pulled them from the basement utility area. It was an easy pull as the conduit was sized larger than needed and there were only a couple elbows.

Wire pulled into the transfer switch

I drilled a 1" KO sized hole through the back of the box and siding and installed an air conditioner disconnect connected with a chase nipple so that I could pass the conductors outdoors and through sealtite to the generator. I did not use the disconnect portion of the enclosure as a disconnect is not needed.

The conductors run though flexible weatherproof conduit

The sealtite connected to the back of the generator with a 90 degree fitting and I terminated the conductors on the 65 amp breaker inside the control panel of the generator. The arrow points to the entry point of the conductors.

Power connections

The entire unit is grounded through a ground lug on the back of the unit. I drove an eight-foot ground rod in beside the generator and connected it with a #6 copper wire.

Generator is grounded

Although the generator has most of the sophisticated control components itself, it needs information from the automatic transfer switch to know when the utility current has failed and when it has returned to full capacity. To accomplish this the unit requires four control wires to connect the switch to the generator. Since these are low voltage wires they need to be in a separate conduit. Generac did not provide a knockout for this conduit so I used my knockout cutter (red arrow) to produce the proper sized hole.

Producing a knockout

I installed a conduit from the generator to the switch through the crawl space. This picture shows the four wires connected to the terminal strip. I had to mark the four wires with the appropriate numbers as the polarity makes a big difference on this installation.

Control wires in generator

I connected the four wires to the terminal strip in the switch.

Control wires in switch

Perhaps the most difficult portion of this project was cutting the utility service and re-routing it through the switch. The picture below shows the utility power coming into the switch from the conduit on the bottom right. Then the power leaves the switch through the conduit on the lower left and enters the house panel and connects to the main breaker. This required nearly two hours of work, most of it in the crawl space where I cut a 2 PVC conduit to allow a junction box where I used compression connectors to splice onto the aluminum conductors.

Utility service run through switch