Standby Generator

Plan 'B' Power Supply

Mrs. Cog: We recently completed a major addition to our long term Plan B preparations when hubby installed a Generac propane powered whole house standby generator. To say that this was not your standard run-of-the-mill installation would be an understatement. For this portion of the program I turn the blog over to hubby for his show and tell presentation.


Cog:  After several months of research into both the various types and brands of standby generators as well as multiple installation methods, including a complete assessment of our home's unique electrical setup (two 200 amp services rather than the normal one) and construction method (a log home that was half factory built and half custom built on site) we decided on the 17 kilowatt Generac propane powered model with a separate 16 circuit transfer switch instead of the whole house transfer switch.

There just wasn't an easy or cheap way to separate one 200 amp electrical service from the other. Transferring the generator over to power both electrical services ran the very real possibility of overloading the generator at any time, especially during a heavy winter load. Using the 16 circuit transfer panel allowed me to select specific critical circuits that I wanted to power with the generator without the risk of overload. Ultimately this allowed me to run nearly everything in the house as well as the water wood stove while building flexibility into the system to quickly switch in or out other circuits as needed or desired, an option that will be most welcome during extended power outages.

After several phone calls to various suppliers we purchased the 17kw Generac online from Northern Tool & Equipment. Overall we were pleased with Northern Tool's customer service and ultimately with Generac, but not with Generac's shipping company. After several missed delivery appointments and repeated warnings from us to use a shorter delivery truck of course they sent it out on a tractor trailer.

Ultimately when the delivery driver stopped at the entrance to our dirt road and would go no further out of fear of getting stuck, neighbors we had never met before offered the driver the use of their pickup truck to off load the 600 lbs of generator/transfer switch and deliver it the final mile of dirt road to our house. A perfect example of neighbor helping neighbor that is unspoken and simply a way of life out here on the mountain.

I directed them to the vacant lot across the road from us that just happened to have an abandoned deck whose height easily matched the height of the rear of the pickup truck deck. I did not want to try and wrestle all that weight down from the back of the pickup in a hurry.

Below you can see the generator partially unpacked on the deck with the transfer switch already unpacked and on a cart ready to be hauled across the street.

Click on the images for more detail.


After setting up a ramp system I managed to muscle the generator down and onto a hand built cart left by the prior owner of our home using a steel bar and rope to lift one side, then the other. Can you say rope burns on the neck and shoulders?


The generator location we selected was about 35 feet from the house on the other side of two rows of 15 year old pine trees that were planted by the prior owner as a wind break. This put the generator out of eye sight with the trees acting as a noise buffer.

However because the generator was placed more than the usual five feet from the house I needed to bury two inch electrical conduit and pull oversized (4 gauge) electrical conductors and 12 gauge control wires from the basement to the generator site.

While digging the trench thru the trees I ran into some very large roots. Rather than damage the trees I carefully ran the conduit under two large root bundles.


The generator feed wire pull was actually done in two stages. The first stage was to pull the majority of the wire from the junction box out to the generator pad. Below you can see the conductors and control cables fed into the conduit at the house with 16 feet left to run into the house later.

Here you can see the other end of the feed cable bundle after it was pulled thru the conduit and out to the generator pad site I had previously built.

An old broom stick came in handy to hold the individual rolls of wire that were pulled down thru the conduit. You can see the loop at the end of the combined bundle where I then tied the rope I had previously buried inside the conduit in order to pull the wire bundle thru. I also pulled thru an extra rope just in case I wanted to add additional wire to the conduit at a later time.


Here you can see where I am now pulling the wire bundle inside the house and into the basement. The extra conduit rope is safely tied off so it doesn't slip back down into the conduit.


After the wife and daughter helped push and pull the generator from the delivery deck across the road to the generator pad site (they worked harder than the slaves on the pyramids) we manhandled it onto some metal pipe and then rolled it on the pad itself. Easy peasy. The pressure treated wood 'box' was pinned to the earth with pressure treated stakes, then back filled with paver base, then pea stone for a nice stable foundation.


Here is an image of the finished exterior installation minus the propane regulator which came a week later. You can see the conduit riser pipe connecting to the generator junction box which then feeds the flexible watertight cable to the generator.


Below you can see the factory pre-wired 16 circuit transfer switch mounted on the basement wall. The armored BMX cable coming in from the top was factory pre-wired to be used as the main feed cable from the generator. But since I located the generator much further from the house than the 30 feet allowed with the original cable bundle I reused and rewired that cable to feed an additional sub panel in the basement (which was powered by the second 200 amp service just to complicate matters) which powers the entire basement as well as the (heat and air conditioner) air handler blower and the water wood stove.

Since this transfer panel was originally designed to be placed within two feet of the main electrical distribution panel, something I could not do because the main panel was shoehorned into the closet wall of the upstairs bedroom, that two foot long main pre-wired connecting cable coming in at the bottom left had to be discarded and new conduit installed and wired. Several of the heavier gauge cables were increased in gauge size to compensate for the longer run. Better safe than sorry.


In the image below the conduit coming in from the lower right is the new upgraded wire bundle feed cable from the generator. Total run from the transfer switch to the generator was almost 50 feet. In this picture (below) I have already stripped out all the factory pre-wire from the transfer switch/16 circuit panel that you see above and connected the newly run and upgraded generator feed and control cables.

The conduit coming in from the lower left is running upstairs into the front bedroom where the main 200 amp distribution circuit panel is located. Inside that two inch conduit are three 4 gauge power feed cables plus a 6 gauge ground, forty two 12 gauge wires, six 6 gauge wires, three 8 gauge wires and six 10 gauge wires. This obviously equals more than 16 circuits, but I wanted extra wires already installed in the conduit to allow me to change circuit panel wiring configurations quickly and easily. I over built for increased flexibility.

Below is the completely re-wired 16 circuit electrical panel in the basement. The extra unused wires that I ran in the conduit for future use are coiled up and stowed away below and behind the breaker panel.



(See image below) Just above the 16 circuit breakers (in the basement generator transfer panel) you will find the automatic transfer switch which contains some mechanical control circuitry as well as the electromechanical transfer switch. When the electronic control panel on the generator itself senses that the utility power has failed (or drops below 60%) it waits 10 seconds, then starts the generator.

Five seconds later it physically throws the switch via the electromagnets and physically shuts off the main disconnect from the outside power and connects the now running generator to the 14 circuits I moved/rewired from the panel upstairs in the bedroom and the 2 circuits from the second 200 amp service panel. I only moved 14 circuits from upstairs because the two basement circuits (feeding an additional basement sub-panel) were already located in the basement and were transferred using a different cable.


Below you can see the upstairs bedroom 200 amp main distribution panel wired for 22 circuits. This doesn't include the sub-panel in the basement powered by the second 200 amp service previously discussed that runs the basement, blower and water wood stove boiler. In the lower left hand side of this main distribution panel you can see where I removed a two inch knock out and drilled out the plywood on the inside of the closet.

This is where I am running the two inch conduit, up thru the closet floor and into the back of the main distribution panel. This main distribution panel is located in the bedroom closet wall within 10 inches of a solid log exterior wall. There was just no other way to work this and still keep a neat appearance in the bedroom. The installed conduit in the closet barely intrudes into the usable space in the closet.


Below is the upstairs bedroom main distribution panel after all re-wiring is complete. Everything is nicely labeled and carefully coiled and routed, especially the extra unused circuits which have been properly capped and taped to prevent shorts. Since I never pulled the utility meter this was a live box I was working on. The wife was carefully watching me to make sure I did not fry myself.

In the upper left corner of the panel in the image below you can see a double pole 70 amp circuit breaker that I added. This actually feeds main utility power to the 16 circuit transfer panel in the basement. In other words what this system does is it takes power from the main distribution panel (in this case 70 amps) and sends it down to the 16 circuit transfer panel in the basement.

14 circuits of the original 22 found in the upstairs main distribution panel are then disconnected from the main distribution panel and transferred down to the 16 circuit sub panel in the basement via all those wires I ran in that two inch conduit thru the closet floor and down into the basement. The remaining 8 circuits stay wired into the main distribution panel and are energized by the main panel. Essentially 14 circuits and the electricity needed to power them have been moved to the basement. Everything else left in the main panel upstairs (8 non critical circuits such as a redundant heating system, outside outlets etc.) still works "normally" until the power fails.

When the outside utility power goes down the entire upstairs main distribution panel loses power including the 8 remaining circuits and the 70 amp double pole circuit breaker feeding the panel in the basement. Remember that the 14 circuits are no longer connected to the main distribution panel, only the remaining 8. The 14 were move/rewired to the panel downstairs.

If the utility power is lost (meaning the utility power is lost to the upstairs main distribution panel and to the basement panel) the generator starts, the basement transfer switch is activated and switches off the connection between the transfer panel in the basement and that 70 amp double pole circuit breaker upstairs. This isolates the panel in the basement from the outside world and prevents the generator from back feeding power through the upstairs distribution panel and outside into the utility lines.

We don't wish to inadvertently electrocute a utility lineman with our operating generator who might be working on the power lines after a storm. Only the panel in the basement is powered by the generator. This system prevents my generator from back feeding into the utility power distribution system.


The completed generator installation after the propane tank was set and lines run. Nice, neat and professional just the way I like it.


Below is an image of the generator itself before I installed the battery and fired her up. This is the re-designed 2013 17kw Generac model with the 992cc V-Twin industrial engine, pressurized lubrication system and electronic controllers. I programmed it to start up once a week and run for 12 minutes to exercise all functions except power transfer. It doesn't switch power over to the house when it is being exercised unless utility power is lost during the exercise.

The actual generator itself is the black cylinder in the bottom middle with the twin cylinder engine to the right. The electronic controller is located top right, intake and air cleaner middle top and the engine exhaust is isolated in the black boxed area to the left. This helps prevent the intake from sucking in its own exhaust. The generator has its own separate cooling air intake located in the back while the engine air intake enters from the right. All in all a real pretty machine.

I was genuinely surprised when, after replacing a low voltage fuse I blew with a replacement I had overnighted to me, she started up and everything worked perfectly. It just didn't feel quite right not having to troubleshoot some stupid mistake I had made. Maybe I'm getting better with old age or maybe I just had some dumb luck. Either way I'll take it.

A freebee that came with the generator that I haven't installed yet is a wireless "Mobile Link" that allows me to monitor the unit from my computer or smart phone. It keeps track of hours run, exercise cycles and maintenance performed which is invaluable if there is ever a (5 year) warranty claim. I can even make changes to many functions remotely. Boys and their toys.


We decided to go ahead and spend the extra money to have the gas company run a second propane line and regulator into the basement where it is stubbed in and capped off. This gives us an additional option when it comes to heating and cooking if we need it. Better to be prepared then to wish you had done so.


After taking delivery of the generator and carefully examining the transfer switch I realized I was at least two pay grades over my head with this project. Thankfully I stopped several times during the installation process and conducted more research before pushing on. I kept thinking about that old adage......"When you find yourself in a hole the first thing you do is stop digging". Words to the wise which I heeded.

3 thoughts on “Standby Generator”

  1. I may be Captain Obvious here, but make sure to do the maintenance on the generator. We have one, and being more or less hapless by nature, we forgot to do the annual stuff — fortunately when the weekly test threw an error we could get the parts in and a service tech out to get it up and running before the next storm hit, but frankly, the work would have been much more easily accomplished in 60 degree weather than it was at 20 degrees.

    1. That is very good advice and if it were up to me… I would prolly forget the annual stuff. Cog, however, has a very personal relationship with that generator. He has even installed a small modem in it so it texts AND emails us each time it has the hiccups, sneezes or runs in test mode. As part prank, part learning experience, Cog has the generator emailing and texting the teenager as well and threatens to add other people (like my mother lol) all the time to the list of people it corresponds with.

      Glad to hear you were able to get yours serviced before the next bad weather. :-) What a season it’s been!

  2. I’ll second that – run the thing just to make sure it works now and again. Being off the grid – I learned early to have hot spares for my hot spares. Generators only seem to fail in ugly weather and on weekends when no parts are available.

    While my main, solar powered system is a bit more complex, my backups are actually simpler. The main system has every power source feeding big batteries, and the campus runs off inverters from that, 24/7. So all I have to do is keep the batteries up to a reasonable charge – cycling them shortens their life anyway, so I baby those expensive things.

    It turns out that in my (very different) case, that all I need is to keep up with my *average* watt hour use, which isn’t that high unless I’m deliberately using a lot (welder, lathe and so on). So, it turns out my main backup is a 1kw Honda inverter-generator (about 90cc), which delivers about 600w (over twice my normal draw) into a battery charger from a forklift system. I also had a larger, cheaper, generator, in fact, I’d at one point collected quite a stack of those that all failed in use (your basic hardware-store 5-6hp thing) since the use-case didn’t really fit them. And they were FAR less efficient than the Honda running almost wide open (gasoline engines are like that – they are most efficient at full throttle at the torque peak – compression ratio and pumping losses matter). After hauling off a stack of those to the metal recycle place, I’ve not bought any more of them, they are just too flakey. The Honda copies use (like Honda) a pressed on cam drive gear. When that slips, it’s toast, as it bends valves. Or they spin the shaft seal and die from that, and it’s in a bad place to fix.

    Now that I also have a Chevy Volt, I use it as a secondary backup. For one thing, there’s most often 10 usable kWh in its own HV battery, that it can push into its smaller 12v battery on demand. I added a 1.2kw inverter to the 12v system, which can in turn drive the forklift battery charger on the campus system. You just move the extension cord to the backup source (and there’s never an actual outage on the mains – not even one half cycle – computers don’t crash and so on). In the case of the Volt, you just turn on the car and the inverter, and it takes care of only running the main engine when the big battery gets low. At equilibrium, it runs about 90 seconds every 15 or so minutes under my loading and uses even less gasoline than the tiny Honda! This is because, of course, they could afford to do a much better job in the car. Variable cam timing on both intake and exhaust separately (it doesn’t even use a throttle), higher compression, controlled temperature, stuff like that. And since I drive the car, and it was actually designed by experts at making things live outdoors, it’s one heck of a lot more reliable than most fixed-installation generators already. It gets checked for working automatically, since it’s also how I get beer and catfood.

    Worst case, I can simply hunker down, like the old bad days. My battery bank will run me for weeks if I simply turn off most of the inverters that drive the conveniences, vs the one that runs the very-necessities.

    Here’s a link on my trusty little Honda – it has another advantage – I can lift it and take it in to the warm/dry to work on it when required.
    I also use it for my electric chainsaw in the woods. Since I’m taking in a tractor to get the wood back out anyway, this is worth looking at – it’s a lot less total work, it’s more reliable than a 2 stroke chainsaw, far quieter…uses less gasoline. And the saw weighs a lot less for the same cutting ability – a biggie for me, I’m a small guy. You just have to be a little careful to not cut your cord.

    And one on the Volt based system. This is old, before I’d worked out the main solar upgrade (which is on the same subforum on my site as well). This last time – neither was really needed, the panels shed the snow.

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