Whole house generator

Pre-64

Sergeant of the Hide
Belligerents
Minuteman
Dec 14, 2019
321
902
99
I live in a rural area, looking to get a generator for my house. I want to get a portable one in case it needs service. Friends that have a permanently mounted standby always complain it’s hard to get someone out to service/fix it. I would like to run my water pump, heat pump, water heater, central air, fridge and a light or two and the tv. If I add all the amps up in the fuse box it goes to about 300 amps, can someone tell me what size generator in watts that would require? I’ve tried doing the math but I’m stupid. I’m thinking a 9000-10000 watt generator would work? Thanks for the help.
 

rjacobs

Sergeant
Belligerents
Mar 10, 2013
1,288
437
189
10 KW generator is only about 40 amps...

A permanent mount whole house biggest you can REASONABLY get is 22kw... that will run about 90 amps... Most will not run central HVAC or at least not recommended. They also have auto transfer switches and a bunch of other stuff...

Most portable interconnect kits are limited to ~30amps.

And you dont do an amp draw assessment by adding up the breaker panel, way more involved than that. You aint drawing 300amps as your main shutoff is likely a 200a breaker
 

Jscb1b

Old Salt
Belligerents
Minuteman
Dec 22, 2018
3,094
4,948
119
Cummins has a kw calculator on their website. Real easy to use. My SWAG for your house is 25kw.
 
  • Like
Reactions: M76 and BAMCIS

rjacobs

Sergeant
Belligerents
Mar 10, 2013
1,288
437
189
Cummins has a kw calculator on their website. Real easy to use. My SWAG for your house is 25kw.
Anything higher than 22kw from Generac or Cummins Onan(I am 95% sure) goes to water cooled and the price SKYROCKETS...

22kw Generac is like $5500-6000 plus installation(couple thousands) plus needs a 500 gallon propane tank minimum.

Ive done a TON of research on whole house generators...

To the OP: how many times in the past 5 years have you been without power? Thats the question that was asked to me by a few people including the Generac and Cummins sales guys...
 

TxWelder35

Online Training Member
Online Training Access
Belligerents
Minuteman
Oct 17, 2018
896
876
99
DFW
Buy an engine drive Welder.

My Lincoln Ranger 250 GXT is a 11000 watt generator and has a 50 amp 220v plug you can wire into your panel with a heavy duty cord with the help of an electrician.

$4500 plus you get a welder...
 

W54/XM-388

Online Training Member
Online Training Access
Belligerents
Oct 1, 2005
8,147
14,597
219
Dallas, TX
I would like to run my water pump, heat pump, water heater, central air, fridge and a light or two and the tv.
One quick note is that for anything needing heating, such as house heating, water heating, cooking and such, it's way more efficient to use the fuel to generate heat directly rather than to make electricity with it and use the electricity to make the heat. If for example you were to put in a big propane tank you could run the water heater and house heater and cooking off that.
 

Maggot

Kill a Commie for Mommy
Belligerents
Jul 27, 2007
11,924
7,698
219
Anything higher than 22kw from Generac or Cummins Onan(I am 95% sure) goes to water cooled and the price SKYROCKETS...

22kw Generac is like $5500-6000 plus installation(couple thousands) plus needs a 500 gallon propane tank minimum.

Ive done a TON of research on whole house generators...

To the OP: how many times in the past 5 years have you been without power? Thats the question that was asked to me by a few people including the Generac and Cummins sales guys...
Another option is Briggs and Stratton Commercial. A buddy of mine sells and installs them. Says the service and warranty R&S is much better and they are more reliable.
 

roostercogburn98

Private
Belligerents
Nov 3, 2010
1,280
2,727
219
Generac has a calculator on their page as well. 22kw is what it told me and I run gas for water and cooktop. That also means I have to turn the shop off or go bigger.
 

candyx

Private
Belligerents
Minuteman
Apr 6, 2014
2,423
4,242
219
Home Depot gas generator with 220V runs my entire house when we lose power , well, refrigerators,heat and AC. Portable starts with one pull runs all night.
 

Jscb1b

Old Salt
Belligerents
Minuteman
Dec 22, 2018
3,094
4,948
119
Home Depot gas generator with 220V runs my entire house when we lose power , well, refrigerators,heat and AC. Portable starts with one pull runs all night.
How many watts is it?
 

respiegel

Private
Minuteman
Jun 20, 2020
30
19
12
Alabama
With a full sine inverter you can make 220VAC from a 9V battery, just a matter of the conversion efficiency...

When we do need the generator i just wire it up to the HVAC disconnect outside and back feed the panel after turning off the main breaker from the meter and that's enough to run the refrigerator, lights, hot water, and the TV

If you have 110v, you can make 220.
 

Do-nothing

Sergeant of the Hide
Belligerents
Minuteman
May 29, 2019
166
181
49
Generator electricity is expensive electricity. I have natural gas heating, cook top, and water heater. I also have a gas fireplace. I had an electrician wire my panel with an appropriate disconnect and back feed so I can run a portable generator for electricity. We don't loose power all that much but it happens on occasion. I can run the fridge, lights, etc, with no problem and heat if I need it. I have a 6800 watt Rigid generator from Home Depot. If I keep the load at 50% or so I can go about 8 hours on 5 gallons of gas. We treat not having electricity like camping out without the bugs.😎
 
  • Like
Reactions: Zeroit and Pre-64

MadDuner

Rankless Infidel
Belligerents
Minuteman
Sep 6, 2019
1,114
2,641
119
Pros and Cons and Compromises...
If you are talking about running a whole house, you are talking in the 30 to 40 kw range. That means water cooled, whether it’s NG, Propane or Diesel. Propane will store forever - but takes 3.5X as much fuel for the same output as diesel. Diesel stores for about a year. Obviously if you can slim down your demand for power, you can get down to air cooled range and also include gasoline. But of course gasoline stores for even less time. But as was just said - generator power is expensive!
 

Bolo

Apprentice of Disaster
Belligerents
Minuteman
May 26, 2020
102
136
49
New York
Don't take this the wrong way... I swear I'm not a tree hugger, but is solar a possibility? Add in a couple of Tesla Powerwall battery packs so you can run off-grid.
Depending on how expensive your electric company is, you might get lucky and have a pretty quick ROI (10 years or so).
Otherwise.. I'm a big fan of Kohler. Pretty bulletproof and easy to get parts, dirt simple to service. 17kW runs my 2700sf house, AC and all, without breaking a sweat.
 

FS1

Unbalanced
Belligerents
Mar 24, 2014
5,299
8,669
219
Earth
When using a genset the thing most folks don't get is motor starting. Motors need 3-4 times run current to start. running motors no problem, starting them is. This is even more critical if by some chance two motors try and start at the same time.

I have a 20kw Nat Gas genset. My hot water is gas on demand, drier gas and stove also gas. All need electric to operate. Not much but they can't run without it. So my biggest load is AC. Like I said above, motor starts are the critical factor. You can damage motors with low current starts. I have enough genset that If my AC and fridge or my AC and clothes drier start together I won't lose one or the other.

Also if you go portable you can manage the load manually with the breakers. Turn AC off then water heater on, after shower, water heater off AC on. But you can't just ignore the load. You need at least 12kw to run a house central AC and that's pushing it on starting.
 
  • Like
Reactions: Srgt. Hulka

BAMCIS

Sergeant
Belligerents
Minuteman
Jul 26, 2006
342
275
69
CO
Onan/Cummings
Kholer
Generac
You'll need to size your needs
Fridge,,separate freezer,, in floor radiant,,
Water heater,,any gas appliances,,heat,,gas/ wood insert? Well? City water?
Use data plates off appliances to gather info. Use amperages,,wattages.

Once spent 8 yrs installation service.
Most were LPG,,rural CO Western slope .
There were exceptions
One even got a duel fuel NG/ LPG,,as well as 40 solar panels,, inverter,transfer switch.
As a resource I recommend get a copy of Backwoods Solar catalogue.


If you need standby,,
Get a automatic transfer switch.
With a battery pack,,48v system.
Set up that gets charged continuous by your grid power,aka powerline supplier.

Set up properly,,it'll switch over automatic to battery system.
24v,,48v sytems

Also use your tax dollar based funds check resources at National Renewalable Labs


For water / well pump,,only one name
Windy Dankoff

 
Last edited:
  • Like
Reactions: Sean the Nailer

brianf

Private
Belligerents
Apr 8, 2010
2,571
2,604
219
43
NY
Also need to balance loads in the house.
No matter how big if you microwave, fridge, coffee maker is in the same leg of the house you might overload a large genset.
It has the gross power but your dumping it all on one half of the actual generator (not the engine).
 

346ci

Sergeant
Belligerents
Mar 26, 2010
1,129
108
169
NC
No way I'd pay $6k+ for a briggs lawn mower engine genset, even more so when you find out how inefficient the LP fuel is to run it.

I was close to buying a used 25kw diesel as we have a tank here for the tractors. 2018 was rough with Florence and Michael. Ended up going with a used Yamaha EF6300iSDE that is super quite and wired it to the panel, it will run everything but the hvac.

The welder/generator is great if you are a mobile welder, they are not very fuel efficient when used as a home generator.
 

Fig

Janitor of the Hide
Belligerents
Minuteman
Mar 15, 2018
5,729
11,692
119
The Most Dangerous City in the USA
Spend the money. Liquid cooled is the only way to go. Once you’re at a $10k system it’s about $1k per 5 kW more, and it’s good to overkill your needs by at least 5kW. Our Generacs are so quiet and kick over so smooth the only way to know you’ve kicked is the lights slightly dimming for a moment.
Natural gas in the city and propane away from the main grid. Practically zero maintenance and no worrying about life of fuel for either. Poor man’s (on/)off the grid without the huge $$$.
 
  • Like
Reactions: plong

army_eod

Retired Army
Belligerents
Minuteman
Apr 20, 2008
415
529
99
68
AL
How bout a couple of Army Cold War era 15 kw generators?
 

E. Bryant

Gearhead
Belligerents
Oct 25, 2010
2,539
1,960
219
MI
Generators are like tractors, get more hp than you think you need.
Careful with that philosophy - taken too far, you'll pay a price in fuel efficiency at lower loads. For those of us on propane, that means less time.

Generac's website does indeed have a good calculator. With a 16kW unit, I'm good to go on heating and cooling needs. I probably can't fire up the shop air compressor and welder at the same time we're running the dryer, stove, cooktop, and AC; that's a minor price to pay for run time off whatever fuel is in the propane tank when we happen to be out of town and the power goes out.

I did my entire install. The unit with one 200A transfer switch was ~$4000, then I added another 200A for the shop ($700). There is probably another $800-1000 in all the other miscellaneous material for running propane to the unit (including a larger supply line from my tank), wiring from the unit to the transfer switches, and redoing the wiring from the meter pan to the existing service disconnects (I have a Class 320 service drop to the house and shop, so everything is 2x). Figure about 40 hours of total time in the various install tasks, which saved me $3000 compared to the quoted full install from a local dealer. Everyone can decide for himself whether that's a good trade-off. It was a good project to keep my sons and I out of trouble for a few weeks.

My main regret is not making the appropriate accommodations when I redid the service entrance and propane supply during a big remodel about eight years before installing the generator. I would have saved myself from doing much of this work twice.

IMG_20200610_091257.jpgIMG_20200622_200935.jpgIMG_20200622_201438.jpg
 

Gunfighter14e2

Rusty Nail
Banned !
Belligerents
Jul 9, 2002
7,948
10,749
219
Alabama
eHam.net
With a week or two behind me in the EPG field, I would suggest never even thinking about a gen-a-junk or junk-a-rak. In the size your going want once you learn more, do not buy a 2 pole unit (3600rpm) flyapart. Also never buy any whole house genset from a Mfg that sells their shit in/threw/with box stores. When you buy a genset you will either pay for it up front an never worry, or on the back side with tons of heart burn.
 
  • Like
Reactions: Maggot

Fig

Janitor of the Hide
Belligerents
Minuteman
Mar 15, 2018
5,729
11,692
119
The Most Dangerous City in the USA
I’ve never had a lick of trouble In about ten years, and I have three. Definitely not the most expensive, but not made to run indefinitely either.
On one of them I have a separate tank with a bridge to the main tank as that whole house is propane, and it’s a rental property. The tank gets topped off once a month, but sometimes it’s down as low as 50% if they’re running the pool heater and there’s 10+ people per week. It would be my luck a hurricane hit when the tank’s at 50%, so I added an even bigger tank dedicated to the generator.
 

MadDuner

Rankless Infidel
Belligerents
Minuteman
Sep 6, 2019
1,114
2,641
119
Don't take this the wrong way... I swear I'm not a tree hugger, but is solar a possibility? Add in a couple of Tesla Powerwall battery packs so you can run off-grid.
Depending on how expensive your electric company is, you might get lucky and have a pretty quick ROI (10 years or so).
Otherwise.. I'm a big fan of Kohler. Pretty bulletproof and easy to get parts, dirt simple to service. 17kW runs my 2700sf house, AC and all, without breaking a sweat.
I manufacture diesel generators for a living, and have a 40kw unit on a trailer parked in the back yard. Not quite a tree-hugger here either.

I’m working on a solar arrangement to maintain a large battery bank. My main concern is enough solar power and battery pack to run lights, comms, microwave, freezers and refrigerators. HVAC and electric water heater are not going to be necessities if SHTF. If everything else is off, the sound of a diesel generator running can be heard for a long way, and I sure don’t want to turn myself into any more of a target than I need to. I can cover my necessities with 6kw worth of resources.
 

W54/XM-388

Online Training Member
Online Training Access
Belligerents
Oct 1, 2005
8,147
14,597
219
Dallas, TX
But of course gasoline stores for even less time.
Buy ethanol free gasoline for the extra money and add stabilizer to it, and if stored in good cans, it will last 12 to 18 months without a problem.
Then just pour it into your daily drivers when it's time to rotate.
 
  • Like
Reactions: Jefe's Dope

seansmd

In a minute man
Belligerents
Minuteman
Aug 8, 2018
1,462
1,036
119
San Jose, CA
I had a generac gp8000e, and a interlock kit for my panel it allowed me to run my whole house including the well, pump, fridges,tvs etc. This allows you to safely back flow your whole panel and select circuits very cheaply. You still have to turn some stuff off but are doing it on the panel.
 
  • Like
Reactions: Pre-64

dang472

Sergeant
Belligerents
Feb 3, 2012
591
217
49
36
Kingston, IL
I’ve had a 16kw generac with the automatic transfer switch for 4 years. It has saved my ass numerous times when I’ve been out of town or the wife has been home with the kids without me. My house is a 1700sq ft ranch with a full finished basement. Everything runs on the generator. The transfer switch has a load sensing feature that will delay the A/C if there’s too much running but I haven’t had that issue. My main appliances are propane so that helps. Also all light bulbs are LED and all my wiring is modern Romex with a ground.
 
  • Like
Reactions: Pre-64 and Fig

Xshot

Private
Belligerents
Dec 21, 2009
257
193
49
68
Evansville, WI
I have a Kohler 10Kva Kohler diesel (Kubota)genset. Came out of an offshore racing trailer with less than 300 hours. My main electrical panel is in the heated shop, house is fed by it, and the genset sits right next to it on industrial caster wheels. When power goes out, I just wheel near the overhead door and run flexible exhaust pipe under it. Sips fuel and powers heat, well and AC no problem. Best part is by being a DIY guys on cost me $800.00 bucks.
 
  • Like
Reactions: BAMCIS and MadDuner

MadDuner

Rankless Infidel
Belligerents
Minuteman
Sep 6, 2019
1,114
2,641
119
I have a Kohler 10Kva Kohler diesel (Kubota)genset. Came out of an offshore racing trailer with less than 300 hours. My main electrical panel is in the heated shop, house is fed by it, and the genset sits right next to it on industrial caster wheels. When power goes out, I just wheel near the overhead door and run flexible exhaust pipe under it. Sips fuel and powers heat, well and AC no problem. Best part is by being a DIY guys on cost me $800.00 bucks.
Those little Kubotas are sweet!
 

Paul Bergara

Sergeant of the Hide
Belligerents
Minuteman
Jan 13, 2019
296
51
34
I have a Generac 22 kw generator with a whole house transfer switch that runs everything in the house. I'm fortunate to be able to use my Town's natural gas service as opposed to a tank. You might want to download the maintenance manual for the specific unit your interested in to get an idea about normal service. I perform the service on my unit which is not frequent or difficult. Best of luck with your selection.
 
  • Like
Reactions: Pre-64

Pre-64

Sergeant of the Hide
Belligerents
Minuteman
Dec 14, 2019
321
902
99
Thanks for all the replies, so when I look at the breaker box it has two switches that are connected to several things, like the water heater, furnace, water pump, so on, both switches have 30 on them, is that 30 amps or 60 amps?
 

E. Bryant

Gearhead
Belligerents
Oct 25, 2010
2,539
1,960
219
MI
A municipal gas utility is not immune to catastrophes.
Agreed, but if one is suffering simultaneous failures of power and gas, then we're talking about countermeasures that go well beyond a standby genset.

The Generac units are easily converted from NG to LP by flipping a lever, and someone who is normally on NG could plumb in a LP tank (better be a proper tank - not one of those 100lb portable cylinders), regulator, and selector valve. Good luck getting that arrangement signed off by the local mech inspector.
 

Gunfighter14e2

Rusty Nail
Banned !
Belligerents
Jul 9, 2002
7,948
10,749
219
Alabama
eHam.net
Mine is a dual fuel, NG as primary an two 250gallon LP tanks as backup to that. I have ran mine (25KW) on wood gas an she banked out at 19.2 KW still plenty for everything here. However I sold the gasifier but have everything to build another. Just wanting the Steam project finish, before jumping on the gasifier, and this time it's not for sale,...LOL
 

seansmd

In a minute man
Belligerents
Minuteman
Aug 8, 2018
1,462
1,036
119
San Jose, CA
I'm still sticking by the 7-8kwgen and the interlock. Wheel it out, fire it up, plug it into a dedicated 240 outlet and run what you want when you want. Installed less than 2k with the generator. No extension cords running through the house as you have to do with a gentran type system unless you get big enough to run your whole house.
 

Badfinger

Major Hide Member
Belligerents
Minuteman
Aug 11, 2013
1,723
2,735
219
68
Dayton, OH Area
We have a 20kw Generac on propane with the automatic switch and love it. If the power goes off we count to ten and it's back on.
 

Racer88

Firearms Pedant
Belligerents
Minuteman
Nov 10, 2018
961
1,218
99
I'm in hurricane country (Florida). Semi-rural area... house is on well water. So, if we have no power, we have no water.

15 years ago, just days before hurricane Wilma, we had a full-house standby generator installed. 25kw. Runs everything, including central a/c. 500-ga propane tank underground. Automatic transfer switch. It's a Coleman, which isn't made anymore. Runs on a 2.5-liter 4-cylinder Ford engine (liquid cooled). Coleman got out of the generator business years ago, unfortunately.

Our generator maintenance dude raves about our generator (says the components are industrial grade) and is NOT a fan of Generac. I don't know which brand he recommends now (I'll ask him tomorrow, since he'll be here). But, I know he thinks Generac is shit, based on the maintenance / repairs he has to do on them.

I believe locally-stored LP is the way to go for fuel. 500-ga minimum. Utility-supplied NG can be interrupted in natural disasters.

Gasoline has two issues... it goes bad, unless you rotate it (as mentioned above). But, the bigger issue, IMO, with gasoline is that it's DANGEROUS to store in large quantities. Diesel is not as dangerous but also has storage longevity issues.

Our system was $11,000 soup-to-nuts fifteen years ago. When the power goes out during a hurricane, and it always does, it's NICE to have everything working like nothing happened.