Home Backup Generator.

[Drew]

We are considering a home backup generator. Looking at Kohler and Generac. I wanted to check and see if the HiveMind had any constructive input? So far the plan is auto transfer switch, natural gas fuel. 20 kW. We have natural gas at the house, gas furnace.

My understanding is that the electrical side is pretty simple... split ground and neutral in what is now the main panel, route their blocks and the hots to new transfer switch which is now the main panel, and what was the main panel becomes a subpanel. Ground and neutral get bonded in the transfer switch (new main panel).

Wild Card is manual transfer switch, portable generator, and we take a risk of something happening while we're out of town... cuts the cost in half, but the Point of the Exercise is to not have to think about this anymore.

Any other brands? Kohler and Generac both have dealers here that have been good so far, both have provided quotes.

Any other input would be much appreciated. Grazi.

[Mabouya]

A buddy of mine at work recently went through the Kohler vs Generac decision and got a Kohler. I believe his choice was driven by the fact that Kohler had a model that met his requirement without having to go with a liquid cooling system. (going on memory here, I'm not 100% sure of that final point) He has the automatic transfer switch system, specifically so he doesn't have to worry about it if he's out of town.

One down side was that there was a very, very long wait for the hardware (well over 6 months) due to COVID supply chain issues. Check to see if those have been resolved.

Good Luck

[gregl]

We purchased a 16KW, air-cooled, Generac unit two years ago. The installation was as described in the OP, natural gas fuel and automatic transfer switch. I am pleased with the unit’s performance and would recommend Generac to potential buyers. The local dealer did a good job on the installation, with minimal issues noted by picky me. Here’s the positives from my perspective:

- It works reliably, exactly as advertised. We sized the generator for the whole house, including AC. It’s super convenient to have every feature and appliance in the house usable when the power fails.

- IMO it’s well designed and constructed. I do my own routine maintenance and I’m always impressed with the unit when I have it opened up.

- The unit runs and self-tests weekly, bi-weekly, or monthly as desired. We configured this to occur mid-month, mid-morning to avoid annoying the neighbors.

- Routine maintenance is very simple. The unit is designed for easy access to all maintenance items. After maintenance, you need to reset the maintenance minder. If not reset and maintenance intervals are exceeded, the unit won’t start. Pro tip: make sure the installer gives you their maintenance reset code. I told the dealer that I wanted the option to perform my own maintenance or no sale. Accordingly, the code is written inside my owner’s manual.

- The unit is well suited to cold weather. The battery and oil systems have heaters to ensure the unit starts well in cold temps.

Only two issues I don’t care for: (1) It’s a bit noisy. Not too bad when you’re inside with doors and windows closed, but it’s a good idea to install the unit as far as possible from bedrooms. (2) You have to pay an annual subscription to use Generac’s web-based monitoring and control app. After paying $$$ for the system, monitoring should be free!

Hope this helps!

Greg

[monadnocky]

Whole-house Kohler here (where we lose power A LOT), 16KW. We have a local generator guy do the yearly maintenance; all I do is just add oil when it's needed (it's rarely needed).
Monitoring app is free and pretty handy. Can even start the thing if you're in Timbuktu, if you wish.
Self-test we have scheduled for 20 minutes every Sunday at noon.
It's noisy, relatively so, like Gregl said, but not obnoxiously so. Still, place it away from bedrooms if possible.
We feed it from a buried propane tank - not sure of the size of the tank, but even with two of those snowman-sized bottles I wouldn't be confident of it lasting for more than a couple of days here.

[monadnocky]

- The unit is well suited to cold weather. The battery and oil systems have heaters to ensure the unit starts well in cold temps
Greg

Greg- I'm curious about this - how does this work? I'm not aware if my (Kohler) has any such system and I think it would drain the battery pretty quickly? Never had a problem starting up, even in very cold weather here in NH, so now I'm wondering if there is something and I'm not even aware of it? I'm not aware of any (domestic) power being supplied to the unit.

[gregl]

Greg- I'm curious about this - how does this work? I'm not aware if my (Kohler) has any such system and I think it would drain the battery pretty quickly? Never had a problem starting up, even in very cold weather here in NH, so now I'm wondering if there is something and I'm not even aware of it? I'm not aware of any (domestic) power being supplied to the unit.

Domestic power is supplied to the Generac system under normal circumstances. This enables battery charging, heating, and system diagnostics to be continuously powered. Both the battery and oil filter have electrically heated blankets around them.

Greg

[monadnocky]

Domestic power is supplied to the Generac system under normal circumstances. This enables battery charging, heating, and system diagnostics to be continuously powered. Both the battery and oil filter have electrically heated blankets around them.

Greg

Huh, looking online I see that Kohler has these kits as well. Now I'm thinking that, when it was installed, they might have hard-wired these accessories, as my unit routinely starts up in less than 0 degrees F. I'll open it up later today and check it out now that I know what these look like.
Things I never knew....

[jclay]

This doesn't address your questions but if you haven't thought about fuel consumption vs the outage situations your planning for it might be worth some head scratching.

We have several short outages/year (two to four hours) and occasionally as many as a half dozen/year; at this point just about every house in our 'hood has a whole house genset. Fuel isn't a problem for these relatively short outages but when a hurricane knocks power down for a week or two, which has happened here several times during our tenure, it will be for the larger machines. LP deliveries won't happen, most gasoline stations will be down, the others inundated and traffic snarled. I went the small machine, small fuel storage requirement, minimal, but adequate, household systems support route.

I decided that running an adequate subset of our utilities (lighting, ceiling fans, fridge, TV+Internet) with a small machine having a small fuel demand made most sense. A Yamaha 2200 watt inverter genset with a two or three gpd max fuel consumption and a manually switched sub-panel does the trick for us (and it's quiet). To do it over I might get the 3500 watt unit but it really hasn't been necessary for us. During the usual two or three hour outage we live pretty much as normal, sans water except for what the pressure tank provides. But when a hurricane hits and power is down for a couple of weeks, which has happened to us a couple of times, a relatively modest fuel supply will suffice. Water is the only potential issue but since hurricanes are well announced we plan accordingly and store enough to get the job done. I have considered getting a 240 v non-inverter unit for the well pump but so far it just hasn't been worth the dosh or trouble.

Going this route requires careful planning and power budget figuring (refrigerator going into defrost mode is our largest power hog) but it might be worth a thought. And all that said, you may (likely) have a completely different set of circumstances to deal with, like cold weather. But in any event, consideration of fuel logistics vs what you really need to deal with the types of events at issue, is worthwhile.

[ldamelio]

We're an LP (and well water/septic) house - surprisingly off the grid with relatively frequent electrical outages for being on the border of suburbia and rural. I've had a Generac 17kW for 12 years now, fueled by LP. The two tanks will run it for about 14 days - never had to go more than four (hurricane Sandy 2012). It's been pretty flawless. A warranty claim (actually during Sandy) was handled quickly - there was a crew here after dark.

[Too Tall]

@Drew "Wild Card is manual transfer switch, portable generator, and we take a risk of something happening while we're out of town" << That is me.

About 15 years ago we had a need to power the house in case of a extended outage. Despite living in the city, our little corner of paradise is at the end of the line for services and we are out frequently.

What I did was to buy the largest generator on wheels I could get iirc it is 17kv something like: https://www.generac.com/all-products...eries/gp17500e Wired a heavy line from the panel to the exterior of our garage and also made a long generator extension cord. Within the panel I installed a square-d interlock kit ( https://www.geninterlock.com/interlock-kits/square-d/ ) and Bob's your uncle.

Obviously, I did this on the cheap however it is safe and very standard use.

If I were to do it again I'd do it again.

[j44ke]

Keep the mud dauber wasps out of your generator’s gas regulator vent and the other air tube off the engine. I fabricated wire mesh caps for each after the buggers got in and partially filled the regulator with mud. Screening was just enough to keep the wasps out without restricting air flow too much. Wasps seem to love generators.

Also check the oil regularly.

I think the tendency is more often to get too small a generator than too big. My guess is that power outages are more likely to get longer than shorter in the future. Make sure you have the power and fuel supply for longer run times.

Also a good idea to have whole house surge protectors to protect all the chip boards in your appliances from electrical variances during a power outage and generator run. And run UPS/surge protectors on sensitive/expensive appliances to be extra cautious. The amount of computers in things you’d never guess had them is kind of ridiculous. A lot of gas stoves are not off-grid appliances, because everything in them operates by wire, not knobs and valves.

A neighbor has wired in an outlet for an all-in-one battery so the weekly generator tests keep the battery charged. The battery will give him enough juice to run things in the house if the propane tank runs empty and the tanker truck can’t get there immediately. The box is pretty big and heavy, but once wiring is done, it just plugs in. He can just as easily connect to a photovoltaic panel.

[Too Tall]

Jake's neighbor is cool. He gave me detailed plans for that battery. Need to hit Whole Foods first.

Potato-Battery-and-voltmeter-scaled.jpg

[j44ke]

Jake's neighbor is cool. He gave me detailed plans for that battery. Need to hit Whole Foods first.

Potato-Battery-and-voltmeter-scaled.jpg

Hah. He’s probably more of a prepper than a Whole Foodist. Brand of his battery is Bluetti, though calling it a battery is an understatement. It seems to do a lot of things. A few more than those potatoes, except you can’t eat it.

https://www.bluettipower.com/

Our generator is a Winco. It is powered by a Honda engine. It is connected to the house by an Asco Auto-Transfer Switch.

[Mark Kelly]

I think the tendency is more often to get too small a generator than too big. My guess is that power outages are more likely to get longer than shorter in the future. Make sure you have the power and fuel supply for longer run times.

On the other hand generators lose efficiency when run at fractional power: this is logical because the motor still consumes fuel with the generator idling. In rough round terms if a generator uses 100 units of fuel at 100 percent capacity it will use 15 - 20 units at idle; interpolation between those points will give you a good estimate of fuel use at fractional power.

[d.bancroft]

We're an LP (and well water/septic) house - surprisingly off the grid with relatively frequent electrical outages for being on the border of suburbia and rural. I've had a Generac 17kW for 12 years now, fueled by LP. The two tanks will run it for about 14 days - never had to go more than four (hurricane Sandy 2012). It's been pretty flawless. A warranty claim (actually during Sandy) was handled quickly - there was a crew here after dark.

How big are your LP tanks? I'm thinking about a whole house generator, probably next year as this year I have other house projects that the wife has deemed higher priority.

[ldamelio]

They are 120 gallons - so about 120 gallons/week for a 17kW generator running full time.

[Drew]

Thanks for all of these comments.

The quotes for whole-house are expensive, that will be $17k by the time it's said and done. What was supposed to be a simple project turned complicated; the gas company needs to install a bigger meter, run my home at a higher pressure, and install regulators on the other appliances so they still run correctly. Otherwise there is risk that the appliances won't work correctly when the genset is running. Sigh. Never simple. The LP route was explored, but my HOA has a restriction that the tank must be buried, = more dollars and plumbing, about the same as the nat gas issues cost-wise.

Backfeed and manual lockout are significantly fewer dollars, I think I can get that done for about $5k all in, but it won't run the whole house, and if we aren't home, it doesn't work. Also requires a little foresight to make sure I have fuel on hand. But I think I can get one of the Honda suitcase generators - there is a 3200w version now that is "handheld" - and run one leg of the house with the furnaces and lights. Next step is a conversation with the Boss to see what she is comfortable with.

I am leaning toward the lockout and portable generator route. And have enough money left to purchase a nice, mid-line bicycle... like a new Sachs... since his queue just opened... and a Sachs is mid-range... sorry for the sideways cross-thread sarcasm from the "peg does not do gravel" thread.

[Too Tall]

Thanks for all of these comments.

The quotes for whole-house are expensive, that will be $17k by the time it's said and done. What was supposed to be a simple project turned complicated; the gas company needs to install a bigger meter, run my home at a higher pressure, and install regulators on the other appliances so they still run correctly. Otherwise there is risk that the appliances won't work correctly when the genset is running. Sigh. Never simple. The LP route was explored, but my HOA has a restriction that the tank must be buried, = more dollars and plumbing, about the same as the nat gas issues cost-wise.

Backfeed and manual lockout are significantly fewer dollars, I think I can get that done for about $5k all in, but it won't run the whole house, and if we aren't home, it doesn't work. Also requires a little foresight to make sure I have fuel on hand. But I think I can get one of the Honda suitcase generators - there is a 3200w version now that is "handheld" - and run one leg of the house with the furnaces and lights. Next step is a conversation with the Boss to see what she is comfortable with.

I am leaning toward the lockout and portable generator route. And have enough money left to purchase a nice, mid-line bicycle... like a new Sachs... since his queue just opened... and a Sachs is mid-range... sorry for the sideways cross-thread sarcasm from the "peg does not do gravel" thread.

Drew, you'll need a bigger boat. That modest Honda inverter genset will run lights and the freezer but it might not have the peak starting power to run your furnace or HVAC. The rest of what you have in mind is fine and what I use for many years. The link I posted earlier is for 10K + gensets.

[Drew]

Drew, you'll need a bigger boat. That modest Honda inverter genset will run lights and the freezer but it might not have the peak starting power to run your furnace or HVAC. The rest of what you have in mind is fine and what I use for many years. The link I posted earlier is for 10K + gensets.

Copy - thanks. There is capability to run two of them in parallel. But still 120v only. I get what you're saying about the bigger generator... I need to go do the mathalation and figure out what I want to run and how much it will take. Appreciate the input.

[Too Tall]

Copy - thanks. There is capability to run two of them in parallel. But still 120v only. I get what you're saying about the bigger generator... I need to go do the mathalation and figure out what I want to run and how much it will take. Appreciate the input.

As much as I'l like not to spoil your research deep dive a few more things. Running two gensets linked in tandem gives you more need to feed gas. It's really meant more for RV people who want enough juice to run their AC using units they can carry to their pick-um-up-trucks.
For the past couple yrs. I've managed the facilities at a campground. We have two deep water wells and use a Wen brand genset for power backup. I was pleasantly surprised how nice these are and the price is no joke. Also, for the $$ you get dual fuel if that is something you are interested in: https://wenproducts.com/collections/generators Mind the performance numbers when assessing a genset using propane. The rating will drop some.

FWIIW I *think this is the Wen genset we use. Smokin' deal if I say so myself: https://wenproducts.com/collections/...hutdown-sensor