Run one house on two generators?

[IHDiesel73L]

I have two generators. One I've had for years and used to use to power my old house during outages. It's a Craftsman (Generac) 7.8HP 4200W continuous (Not sure of the surge rating) that I got used but it starts and runs well. The other I just recently received as a gift after moving into our new house-a brand new Troy-Bilt 6250W continuous/8500 surge. The problem is, running my entire house on the Troy-Bilt alone is a tall order as my essential loads are as follows:

1/2 HP Well pump (about 100' deep)
Two full size refrigerators
Oil boiler with two circulator pumps and five zone valves
Lighting (eight rooms/2600 SF but mostly LED)
Two flat panel LED TVs
Gas dryer*
Washing machine*
Dishwasher*

*= Would shed other loads while operating these

I feel as though if it were night time with lights on, a TV or two going, refrigerators humming, and the boiler firing, if the pressure tank dropped and the well pump kicked on it would either stall the Troy-Bilt or cause serious voltage drop which is not good in general. Then I began thinking about some way to be able to isolate the well pump and run it off of the Craftsman 4200W alone, which would free up the Troy-Bilt to run the other loads. The question is how to do it safely. I plan to install an interlock device on the panel which locks out the main when the generator breaker is closed and vice versa. However, this doesn't help me with the well pump. I suppose there is a way to do it by installing a small breaker box somewhere downstream of the panel that would allow one to lock out the power feed from the panel and close the generator breaker, but there would be a lot of room for operator error. Anyone have a solution to this?

 

[Rustyiron]

I would think with your list that the 6250/8500 would handle it by itself. The oil boiler & circs are minimum, well is intermittent, you can turn the lights off in empty rooms and I think these LED tv's are miles away from the old 50 pound tv's for energy use.
I've run 2 fridg's & 2 freezers & misc household stuff + the well - 400' on a 3800w. To run it safely without feeding (and listening to) 2 genny's, I'd just throw the well pump breaker and when you need showers, limit the other items.

 

[JPRambo]

I have two generators. 3500/4500 watt and a 6500/8500 watt. I use the 3500/4500 for a well on property in Georgia, well is 3/4 HP and 380 feet works good.
The 6500/8500 I used for both Hurricane Charlie (2004) and Irma (2017) The loads are 1 HP well pump and 3/4 HP house pump, full size refrigerator, full size freezer, lights and fans, 42 LED TV and other loads in a 2800 sq ft home.

 

[Sawyer Rob]

You only need to plug the freezers in a couple hours a day, so unplug them while everything else is running.

Same with other big loads, unplug it for a few hours while the freezers are running ect...

SR

 

[Tractor Seabee]

If load shedding doesn't work for you just set up 2 emergency panels, one for each genset. I have a 17.5 KW that has a 50 and a 30 Amp outlet. The 50 is less than the total output capacity. I put the water heater on a seperate 30A circuit W/DPDT switch for it, 50 went to the emergency panel via interlock breakers. My electrician buddy advised not to connect the two together to increase capacity to 70A on one feeder which can have its own set of problems.

Ron

 

[IHDiesel73L]

The 6500/8500 I used for both Hurricane Charlie (2004) and Irma (2017) The loads are 1 HP well pump and 3/4 HP house pump, full size refrigerator, full size freezer, lights and fans, 42 LED TV and other loads in a 2800 sq ft home.

Just to confirm you ran all of this off the 6500/8500 alone? If so I should be fine-thanks!

 

[LittleBill21]

i have a 7k unit and run more then that, i even run the oven and electric water and dryers while managing the load. you don't need to run everything at once, you need to have both fridges on and the well pump and i doubt you would even be at 80% capacity

 

[CobyRupert]

One could put a 2 pole 30 amp double throw disconnect switch (transfer switch) in the devoted well pump branch circuit so that you can switch pump source between panel and devoted genny. (Redneck/ non-code compliant way is to install a receptacle for the genny into the pump circuit and switch off panel breaker before starting genny.)

 

[buickanddeere]

I have two generators. One I've had for years and used to use to power my old house during outages. It's a Craftsman (Generac) 7.8HP 4200W continuous (Not sure of the surge rating) that I got used but it starts and runs well. The other I just recently received as a gift after moving into our new house-a brand new Troy-Bilt 6250W continuous/8500 surge. The problem is, running my entire house on the Troy-Bilt alone is a tall order as my essential loads are as follows:

1/2 HP Well pump (about 100' deep)
Two full size refrigerators
Oil boiler with two circulator pumps and five zone valves
Lighting (eight rooms/2600 SF but mostly LED)
Two flat panel LED TVs
Gas dryer*
Washing machine*
Dishwasher*

*= Would shed other loads while operating these

I feel as though if it were night time with lights on, a TV or two going, refrigerators humming, and the boiler firing, if the pressure tank dropped and the well pump kicked on it would either stall the Troy-Bilt or cause serious voltage drop which is not good in general. Then I began thinking about some way to be able to isolate the well pump and run it off of the Craftsman 4200W alone, which would free up the Troy-Bilt to run the other loads. The question is how to do it safely. I plan to install an interlock device on the panel which locks out the main when the generator breaker is closed and vice versa. However, this doesn't help me with the well pump. I suppose there is a way to do it by installing a small breaker box somewhere downstream of the panel that would allow one to lock out the power feed from the panel and close the generator breaker, but there would be a lot of room for operator error. Anyone have a solution to this?

It will cost more time and money to Mickey Mouse two generators than to purchase one large generator . Wait till the power fails and sell one generator . Prior to Y2K generators cost $1000 per Kw. Now generators can be purchased for $100 per Kw.
How is the generator connected to the house ?

 

[RSKY]

We were without power for more than two weeks during the 2009 Ice Storm. We started with a 2000 then got a 4000 generator (all we could find) and moved the 2000 to a different home. Had a bunch of heavy extension cords running under the garage door, into the utility room, then throughout the house. Freezers were set at the coldest settings and my wife plugged them in before she went to bed and unplugged them first thing in the morning. Pain in the rear to keep up with but everything was manageable. We had as many as a dozen people staying with us because we had gas logs and therefore heat. Only thing we couldn't do was run the water heater. The point I am trying to make is that with careful management of the load you can survive on a lot less power than you think.

 

[JerryK]

The new gen you bought should run the important stuff you need to have on, and you can turn off/on breakers to manage the rest. I start by shutting everything off except specially marked breakers [ reflective tape you can see by flashlight in the middle of the night when you are half asleep ], shut the main off, fire up the generator then start turning breakers on as needed. I run a forced air furnace and deep well pump with my gen that is similar to yours. The TV's and most needed lights are nuisance loads.. don't really mount to much. So the better half can watch TV, read, or whatever whilst you are outside feeding fuel to the beast and flipping breakers... Here is a picture of my barn panel, which I backfeed. The house is fed off this panel via a 100 amp breaker. I have two switched neon lights clipped onto the feed coming from the meter to monitor if/when the store bought power comes back on.

 

[JerryK]

The plug in freezers and other misc loads you could run via extension cord and your old gen if you wanted......

 

[leciafosl]

I totally agree with Rustyiron, from what you have said, the 6250/8500 should actually handle it by itself. I am actually haiving a similar dilemma right now, as my dad gifted me a brand new generator, and I do not know which one I should be using right now. I've run 2 fridges & 2 freezers on my older 3800w and it was doing ok, so I do not think that using the new generator is a good idea. However, I hope that I would not need the generators in the near future, as we are finally getting the Economy 7 tariffs electricity plans, and hope that we are not going to have outages so often. If you guys are also tired of using generators and of those stupid outages, just read this article What is a Letter of Authority? - Simply Switch , you will understand immediately what you should do.

 

[RalphVa]

I have two generators. One I've had for years and used to use to power my old house during outages. It's a Craftsman (Generac) 7.8HP 4200W continuous (Not sure of the surge rating) that I got used but it starts and runs well. The other I just recently received as a gift after moving into our new house-a brand new Troy-Bilt 6250W continuous/8500 surge. The problem is, running my entire house on the Troy-Bilt alone is a tall order as my essential loads are as follows:

1/2 HP Well pump (about 100' deep)
Two full size refrigerators
Oil boiler with two circulator pumps and five zone valves
Lighting (eight rooms/2600 SF but mostly LED)
Two flat panel LED TVs
Gas dryer*
Washing machine*
Dishwasher*

*= Would shed other loads while operating these

I feel as though if it were night time with lights on, a TV or two going, refrigerators humming, and the boiler firing, if the pressure tank dropped and the well pump kicked on it would either stall the Troy-Bilt or cause serious voltage drop which is not good in general. Then I began thinking about some way to be able to isolate the well pump and run it off of the Craftsman 4200W alone, which would free up the Troy-Bilt to run the other loads. The question is how to do it safely. I plan to install an interlock device on the panel which locks out the main when the generator breaker is closed and vice versa. However, this doesn't help me with the well pump. I suppose there is a way to do it by installing a small breaker box somewhere downstream of the panel that would allow one to lock out the power feed from the panel and close the generator breaker, but there would be a lot of room for operator error. Anyone have a solution to this?

You cannot put 2 generators together unless you have some way of electronically making sure they don't multiply and give you maybe as much as 480 volts.

I agree with some others that you can probably run all that load with 1 generator. I once had a 4400 watt one with similar loads, but I had to take everything off to run the well pump to pressurize my tank and then shut it off. It would not take the startup load of the well pump with anything else on it.

Now, with a 12.5 kw diesel-powered generator, I can run nearly the whole house but the swimming pool pump, 4 ton heat pump and a few other things on the one 200 amp panel. The electric clothes drier can be run if there's room in the generator. I've 4 circuits that only are allowed to come on if there's room in the generator. Never been a problem with not running anything.