When the power goes out and I use my generator I am currently running an extension cord through a cracked door from the garage into the house, down the basement stairs and to my sump pump (which is all that I'm concerned about during a storm, when the power usually goes out.)

What I would like to do is somehow run an extension cord to the interior garage wall, plug it into something that passes through the wall into the basement, where I would have another extension cord already plugged in that runs to the sump pump area where I can just unplug the sump pump from the wall, and plug it into the extension to the generator.

I don't want to wire an inlet to the breaker box and power the whole house, just a line to the sump pump where I can unplug and re-plug as needed. Also, backfeeding and suicide cords are ABSOLUTELY out of the question.

Am I making sense in my explanation? Basically I want a self-contained wall plug that is male on one side that I plug the extension cord from the generator into the wall (garage side) and female on the other (basement) side of the wall that I plug an extension cord into that runs to the sump pump area.

I've seen people suggest just drilling a hole into the wall, sticking a PVC pipe through and just cap the ends when not physically passing a full extension cord directly through a hole in the wall. I don't like that idea. I prefer having a plug on each side of the wall to plug into. Not sure what parts I'd be looking for or whether this is something that would violate electrical codes. I can visualize what I want to do, but I have no idea what the parts would be called or what to look for at the hardware store.

I'm a computer guy, not a tradesman, so I'm not overly handy in this area, but I'm confident I can work it out with just a little guidance. Any suggestions from professionals who know better would be awesome.


3 Answers 3


You need a generator inlet that feeds a single outlet.(you seem to know what an inlet is, but it doesn’t need to feed the breaker box, it could just feed a single outlet.) This new outlet should be placed next to your current sump pump outlet, and properly labeled to avoid future confusion. (Assume here I’m talking about a future homeowner or tradesman— you won’t be confused but others might be in 10-20 years.) This new outlet would be dead when not fed by the generator.

Do NOT run your generator in the garage, it must be outdoors! Generators emit Carbon Monoxide which is odorless and extremely lethal.

(Note: the linked example is weatherproof, non-weather proof models are made for standard knockout sizes the are found on Hoffman-style enclosures, which are typically larger than needed for this project. Since the easiest to install are all weatherproof there is a message there—these should be indoors or in the garage.)

  • Yeah, that's pretty much it. Have an inlet hardwired to an outlet. Use standard wiring methods. May 16, 2018 at 1:58
  • Thanks @Tyson. So, to make sure I understand this correctly, I would wire this directly to just a standard interior wall outlet like I would find for any other wall outlet in the house? And I always run my generator outside my garage, but I have to run the wire in through the door to the house. Not ideal, obviously. :)
    – Tam
    May 16, 2018 at 13:37
  • Yep, regular straight forward wiring, inlet to plug. Your dealing with 15 amp plug configuration, but the circuit breaker on your generator for the outlet is likely 20 amp, if that the case use 12-2 NM-B between the inlet and outlet. Basically your building an extension cord into your house, with a male plug (the inlet) and a female (the outlet) in the other end.
    – Tyson
    May 16, 2018 at 13:45
  • That's perfect. Thank you. One final question though, since the generator is likely outside during a downpour of rain, do I need to have an outlet with the GFCI to trip? Is water a concern?
    – Tam
    May 16, 2018 at 13:52
  • To add GFCI (if your generator doesn’t already have it), for this setup, I’d use an inline GFCI and plug it in FIRST at the generator and continue from there.
    – Tyson
    May 16, 2018 at 14:52

Pardon me for making an XY problem out of this, but I've done the calculations and it doesn't take that much energy to move water.*

It should be well possible within the range of a deep-cycle battery and mains-attached charger. If you had an especially long outage, you could run 12V from your car to top it up.

Simply put, 1 KWH of energy, or about the capacity of a deep cycle car-sized battery, can lift 2,655,220 foot-pounds, i.e. that many pounds 1 foot, or 265,522 pounds 10 feet. If you've got 265,522 pounds of water (31,800 gallons) of water coming into your basement in the time length of a power outage, you've got bigger problems...

Anyway, given the relatively small power requirement, it seems crazy to run a generator. I would look at 12V battery driven sump pump solutions.

* a guy had to lift water 200' vertically but 700' horizontally to supply a hilltop home off city water. He wanted to put in a 20A pump circuit, but 20A voltage drop on the 800' wire run was calling for insanely large wire, like 3/0. I was like Wait a minute. There must be an easier way. I ran the numbers on "energy needed to lift water" and figured out he could use a sanely sized solar panel to pump the water past his cabin to 90' above it, to a storage tank, and the extra 90' of head pressurizes his system. It would be passive and power-failure-proof. All he needed was a "tank full" sensor and 14 AWG would suffice for that.

Anyway, your water lift is a LOT shorter both vertically and horizontally.

  • I've been considering a product called "Ace in the hole" which sounds like a battery backup to a second sump pump which would cover both power and primary pump failures. Thanks for the information, Harper. I appreciate it! I'm going to mark Tyson's answer as "accepted" since it answered my original question, but I thank you for the input also!
    – Tam
    May 16, 2018 at 13:43
  • @Tam I understand (and hardly need rep :) Yeah, the second battery backed up sump pump is a solution I've seen before and seems like a good way to go. Puts most of the wear/tear on the other pump. Still, test it annually. May 16, 2018 at 14:38

I drilled a hole through the house wall where I wanted to locate the aux power receptacle. Put the receptacle box into the wall connected to 14 wire. Ran plastic conduit ( with wire) several feet to where I set up the generator when needed. A short length of wire at the end of the conduit has a male plug to put into the generator. All standard hardware. The 14 wire was an extension cord with the female end cut off.

  • Hrm....400.8 much? Given that you put a conduit in, running proper Chapter 3 wiring to an inlet shouldn't be hard, though... May 16, 2018 at 23:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.