Well pump off of a generator

[Muleskinner]

Hi! New to the forum, glad to have found you folks. Seems like this might be the right place to ask some questions about what we're trying to do.

We have a piece of property on the olympic peninsula that we're building out ourselves and we're attempting to run our three wire well pump off of a generator and have it feed a water holding tank located a few feet from the well itself. All we want to do is run the well pump to fill the holding tank- no pressure tank because all our pressure will come from gravity from the 1100 gallon holding tank as the usage area is located about a hundred feet below the tank. Can anyone help with figuring out how to wire a three-wire 1/2 horsepower red lion well pump w/ a separate control box to a generator, without a pressure switch/tank, so that we can pump water up from the well into the holding tank? It's a 230 volt well pump, we have a plenty powerful generator (9000 watts, 240 volt) with a 4-prong outlet. We simply want to run the generator once in a while to fill the tank as needed, we don't need any kind of automatic on/off system or anything complicated. Would love some help with this!

 

[Boycedrilling]

Simplest? Plug it in with the generator off. Start the generator, and the pump runs.

 

[Sponsor]

 

[Boycedrilling]

Or get a 1/2 hp rated snap switch (light switch). Wire it it in line after the plug. Turn the switch on or off to start and stop the pump.

 

[Muleskinner]

Sorry, maybe I wasn’t clear- the generator is a four prong outlet- two hots and a neutral. The control box for the 3-wire pump only has l1/l2 input connections and a ground. What happens with the neutral? I’d also like to place a breaker between the generator and the control box.

 

[Boycedrilling]

Ok. Go to Lowe’s or Home Depot. Get an outdoor rated 4 to 12 circuit main lug panel. They cost $25-75. You will back feed a 2 pole breaker with the same rating as your generator outlet. Your two current carrying conductors get wired into the outlets of this breaker. (L1 & L2) That’s why is called back feeding. This is now your main breaker for this panel. You will need to install a hold down kit on this breaker. The neutral and the ground wires BOTH go to the ground lugs in this panel, because this is being used as a MAIN panel. They are separated in any sub panel. You need to drive TWO ground rods 8 ft long at least 6 feet apart. They are connected with a continuous uninsulated wire to the ground lug in the panel.

now install a 15 amp 2 pole breaker for the pump. It will take two current carrying conductors and a grounding conductor from the panel to the control box of the pump.

if you want any addition 120 volt outlets, install 15 or 20 amp single pole breakers in the panel. They will have to be gfci protected.

I would use a piece of SO 4 wire cord from the breaker to the generator, with the proper plug wired into it.

I would mount the breaker box and the pump control box on a 4x4 wood post, unless you have some other structure available.

clear as mud?

 

[Boycedrilling]

You don’t need or use the neutral wire in a 230 volt only application. You only need the neutral wire if you have 120 volt loads. The neutral wire is the return path for electricity in a 120 volt application. In a 230 volt application the other current carrying conductor is the return path for the opposite wire. The equipment grounding wire is the same regardless of the voltage or number of current carrying conductors.

 

[Muleskinner]

Ok- this is really helpful, thank you. I have a 60 amp 4 circuit main lug panel now, as well as a 30 amp two pole breaker. You say I need the 30 amp two pole breaker for the generator and an additional 15 amp two pole breaker, I’m thinking I need a bigger panel than one with just two spaces, correct?

 

[Boycedrilling]

Actually with 6 breakers or less, you don’t need a main breaker, per NEC. so you just need the 15 amp 2 pole breaker for the pump. Everything else is optional. L1 and L2 from the generator, go to the main lugs. The ground wire still goes to the ground bar. If there isn’t one buy the ground bar kit. Since this is a main panel, not a sub panel, the neutral wire also goes to the ground bar unless there is a separate neutral bar. I prefer to install a separate neutral bar if there isn’t one. It’s neater that way. To be NEC compliant, you still need TWO ground rods as I mentioned previously. What I have described will be a code compliant installation.

you can go to L&I, purchase an electrical permit, and have it inspected and approved.