Installing Our Whole House Generator

We had some really bad storms and lost our power for over a week. We had a generator and ran an extension cord into the house to the fridge, freezer, coffee maker, microwave, wifi and an electric blanket. So, we didn’t really suffer. But when we were offered a Generac whole house generator, we jumped at it.

This is what was involved in setting it up.

The generator is a Generac Guardian so we looked on the Generac website.

Can I install the generator myself?

As an option, Generac offers the Guardian Series systems prepackaged and pre-wired with comprehensive installation instructions. You could perform the simpler site preparation steps and have a professional make the electrical panel and fuel connections, or you could complete the entire installation yourself. However, for safety reasons and to ensure adherence to all local, state and national electrical codes, particularly for non pre-wired or larger systems, Generac recommends you use an authorized Generac dealer or licensed contractor. When selecting a site, always follow the guidelines in the Site Selection and Preparation section of your unit’s installation manual.

How hard could it be?

Choosing the Generator Location and Site Preparation

• Install the unit where air inlet and outlet openings will not become obstructed by leaves, grass, snow, etc.
• Install the generator on high ground where water levels will not rise and endanger it.
• Allow sufficient room on all sides of the generator for maintenance and servicing. A good rule is to allow three feet of space on all sides.
• Install the generator as close as possible to the transfer switch.

We don’t have a transfer switch yet, but we will put it close to the generator and close to the main service breaker.

It says to “install the generator as close as possible to the fuel supply to reduce the length of piping.” We can’t do that because that is the lowest side of the house. We would have to put the generator on legs like the heat pump.

It also says that if “strong prevailing winds blow from one direction, face the generator inlet openings to the prevailing winds.” But we don’t have prevailing winds.

When our power was out, we put our portable generator behind the carport. There are no windows at all on that side of the house, so no chance of CO2 drifting in and killing us in our sleep. We weren’t the only ones with no power, so the incessant racket of generators came from every direction, but at least it wasn’t right behind our bedroom wall.

We decided that this would be a pretty good location for our new used Generac whole house, automatic generator.

The installation guide says that the genset “must be installed on a level surface. The base frame must be level within two (2) inches all around.

Cliff built a frame out of scrap lumber we had around.

Then he filled it with gravel and leveled it.

Ready to go!

Preparing and Ordering Parts

So Cliff built a frame, filled it with gravel and smoothed it level. We figured the gravel would make sure water couldn’t stand.

He read the on-line instructions for the generator and ordered the parts we will need to hook it up.

He bought a battery, a Group 26 battery for $60. It looks just like a car battery.

Cliff bought an all in one transfer switch from Lowe’s, but when he read the instructions in the box, he realized that was for a new sub-panel service. So, not what we need.

We needed to make our own transfer switch to work with what we have. The whole idea is, you need to be able to have the generator only send electricity to the house. You have to disconnect from the power grid or your generator is sending electricity into the wires to your house. The power company guys trying to fix the lines could end up electrocuted.

We needed a breaker to connect the generator to the house. We needed an interlock so we didn’t kill anybody.  Cliff ordered a generator interlock kit from eBay.

The picture shows it installed, but the interlock is just this little piece of metal. It prevents you leaving the house on the power grid when you turn the generator on. You have to switch off the top 200 Amp switch to be able to slide the metal part up. Then you can switch the generator on.

Adding an external interlock onto an existing breaker panel allows the main breaker to be turned on or one designated load breaker to be turned on, but not both at the same time.

Under normal conditions, the main breaker is on, accepting power from the external mains into the panel, and the backfeed breaker is off, isolating the generator. The external mains feeds the panel, but the panel cannot backfeed the generator.

In generator mode, the backfeed breaker is on, accepting power from the generator into the panel, and the main breaker is off, isolating the external mains.

Backfeeding the external mains is unsafe and illegal, because it can potentially electrocute lineworkers, start fires, and overload or damage the generator.

From Wikipedia, but edited

We only needed a 30 amp dual pole, but we went ahead and put in a 60 amp in case we ever want a larger generator.

We could have put in a dedicated transfer switch so that the power would automatically switch the generator on any time there was a power outage, but they cost a lot more.

Permits

Both gas and electric have to be permitted and inspected. That’s a residential combo permit. The electrician applied for the permit, but it was in the names of both contractors.

They both came out and looked at what we were doing.

The gas guy said we did not have enough gas coming to our house to power the generator, so we called the gas company to increase our gas pressure and volume.

He told us what parts he would need, but he ordered them for us.

Whole House Generator Electrical Connections

The electricians came out first. They installed the interlock onto our panel and put in a breaker from our main power for a trickle charger to the battery in the generator.

They tested all the connections and everything worked.

While the electricians were working, the pipe and other things the gas guy had ordered were delivered.

Whole House Generator Gas Connections

I found out that, at least here, a plumber is who does gas. I guess because they both work with pipe.

The plumber ran gas pipeline from our meter on the other side of the house to the generator.

The pipe that Schumacher used was flexible plastic. The new pipe to the generator is rigid metal.

The hose faucet was exactly where we needed to put the gas, so he moved the hose faucet over.

They used this clamp to hold it in place while they cut it.

It’s just a clamp, to hold the pipe while they cut it to length.

He also ran gas to where we are putting in a gas fireplace.

They put in a support to hold up the gas line to the generator.

The generator uses more gas than our hot water heater and gas fireplace, so he added regulators to the gas line. It acts as a step-down line regulator to reduce the gas pressure to the traditional one-third PSI that residential appliances are designed for.

They sealed where the pipe came out of the wall.

This is a pressure test. The pipe has to pass before they can run gas through it.

The electricians came back to bond the gas pipe to ground. Green means ground. Bare copper means ground.

The inspectors came and checked everything.

And we passed! Approved to have the gas run to the generator.

Dominion Energy

Dominion Energy came out and changed us from 7 column inches to 2 PSI.  7 column inches is standard natural gas pressure, one-third pound-per-square-inch. But the generator requires a lot more.

They didn’t change the pipe to the house. They changed the meter.

This is the new meter. The pipe on the left is the new gas line. The one on the right is the original one going to the hot water heater.

Starting up the Generator

Finally! We can start up the generator!

Cliff had already checked the oil. The gas lines have been tested.

In case we forget, instructions to start up the generator are written inside the breaker box cover.

You start the generator before you switch the interlock over.

When it first started, all of the lights flashed.

This is what all the things on the control panel are.

Then it settled down to a steady green.

It started so fast it startled me, but really it wasn’t very loud. Kinda like a car engine with the hood open.

As soon as Cliff closed the lid, it was much quieter. There is thick insulation all around.

The whole house generator is way quieter than the portable generator.