Need advice on wiring sump pump outlet for emergency generator / 220v split to(2)120v

Discussion in 'Electrical Forum discussion & Blog' started by TSPORT, Nov 5, 2010.

  1. TSPORT

    TSPORT New Member

    Messages:
    46
    Location:
    Philly,PA suburbs
    Hi all. I have a portable generator to power my sump pump in the event of a power outage. Rather than snaking an extension cord that will reach from my driveway to the sump pump in the basement, I am installing a 120v outlet/receptacle next to the existing sump pump outlet and hard wiring it to an "inlet" in the garage that I can hook the generator up to when the need arises. Here's what I need help with. My generator has an L1420R receptacle on it for 120/240V. I have a cord set that fits it. I have a matching flanged L1420 inlet receptacle that I want to put in a box in the garage. My plan is to run the 240 volts using 12/3 wire w/ ground from the garage box down to the basement by the pump. The pump is 120v. Can I use a regular 20amp 120v duplex receptacle down there, seperate the hot side (break out the little tab that connects the 2 outlets together) and then wire the 2 hots seperate ( a red and a black) and run my white neutral to both giving me (2) 120v outlets? Is this sound thinking/safe or am I nuts? What I am trying to accomplish is having 1 outlet available for the sump pump and 1 for a light in the basement when using the generator. Figured I would have more amps available if I used the 240 outlet on the generator rather than a single 120 on it. I also like the twist lock feature so the cord doesn't pop out. The 120v outlets on it do not have that feature. I appreciate any and all input! Thanks.
    Last edited: Nov 5, 2010
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,048
    Location:
    Cave Creek, Arizona
    That scheme will work, although I doubt that the pump AND light together would tax either side of the 240 feed. And certainly NOT need all the amps the generator could provide.
  3. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,559
    Location:
    North Carolina
    The available wattage of the generator will be the same at 120 or 240.

    If the 240 volt receptacle on the generator is GFCI protected then the GFCI will Trip.

    If the generator is not GFCI protected the receptacles in the basement will require GFCI protection so no the tab cannot be broken.

    Does this generator not have 120 volt receptacles? If not then we have a problem using it for 120 volt circuits without the benefit of a transfer switch.
  4. TSPORT

    TSPORT New Member

    Messages:
    46
    Location:
    Philly,PA suburbs
    "Does this generator not have 120 volt receptacles? " - Yes, it does.
    "If the 240 volt receptacle on the generator is GFCI protected then the GFCI will Trip." - No GFCI in generator.
    "And certainly NOT need all the amps the generator could provide. " - The generator is rated 3750 watts. I will only be powering the sump pump and a lamp or two. It's not tapped into the house circuits, I am just creating a "hard-wired" extension cord with a split duplex outlet if you will. As I mentioned before, I mainly wanted to retain the locking feature of the L14-20 receptacle on the generator and make things as easy as possible to keep things running (pump & light) in the event of a power outage to avoid a ruined finished basement. I don't trust the battery back-up pump to do the job in heavy rains.
    Thank you both for your replies.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,048
    Location:
    Cave Creek, Arizona
    For all practical purposes the generator is creating about 15 amps per leg, and your sump pump and light will be LESS than that, so you could use the other leg for something useful, like your freezer or refrigerator.
  6. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,559
    Location:
    North Carolina
    The one thing to think about when trying to make such an installation as you propose is that this little generator is not producing very clean current and anything that is looking for clean current such as electronic equipment will not fair too well with this generator.

    The next question you should be asking yourself is just how safe you want this installation to be. The best answer would be to install the proper size cord from the generator to the appliance being served instead of splitting the 240 volt circuit on this small generator.

    No matter how you choose to make the installation remember that your and your family’s safety lies in the way you make the installation.

    The law mandates that there can not be utility power and generator power on the same circuit at the same time. This means that the circuits you install must be separate and apart from any circuits that the power company supplies. This can be achieved through the required transfer switch.

    Should you make an unsafe installation the power company can turn off your power and refuse to reconnect which would leave you with a generator that supplies a pump and a couple of lights and nothing more.
    The inspections department can also condemn you home forcing you to move out until which time the home is inspected and deemed safe for human occupancy.
    Will these things happen? I don’t know but I do know that it is possible for them to happen and it is a big chance to take just to have something unsafe.
  7. TSPORT

    TSPORT New Member

    Messages:
    46
    Location:
    Philly,PA suburbs
    re: "The law mandates that there can not be utility power and generator power on the same circuit at the same time. This means that the circuits you install must be separate and apart from any circuits that the power company supplies. This can be achieved through the required transfer switch. "

    - My little set-up is not connected in any way to the household power supply, nor will it be. Not sure how a transfer switch would figure in to this. It's just basically a hard-wired extension cord splitting the 240v into (2) 120v outlets. I have no intention of hooking it into the rest of the house, I just wanted to be able to plug the sump pump in and also a perhaps a light in the same room without messing with extension cords. We don't get extended power outages here so I am not too concerned about the fridge, etc.. Flashlights, etc. would be fine in the rest of the house. Again, appreciate the info. - TSPORT
  8. jetlag

    jetlag New Member

    Messages:
    84
    Location:
    Ga.
    A 240 is allowed to be ran this way and is called a multiwire branch circuit , you wind up with two circuit that share a neutral , the neutral only carries the unbalanced load , if both loads are exactly the same , there will be no current in the neutral . like one of the posts said if the 240 was on a GFCI it would trip because of the shared neutral . The problem with this set up is In the unfinished basement or crawl space where the sump pump is , the receptales must be GFCI , and there is no tab to remove , you cant put different circuits on the top and bottom screws .,, Now you could do this if you install a 2 gang box with 2 Gfci receptacles one hot to each recept and share the neutral .. But I really hate for you to do this , do yourself a favor and use the 120 outlet on the gen and install a gfci receptacle by the pump , but only do that if you have an approved inlet connection for the 120 . Dont use a male plug on both ends of a cord and fed into a recept , they call that a " widow maker " cord
  9. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Poor guy just wanted 2 circuits to use a few hours a year, and now his house is being reposessed and he's buying a 300$ transfer switch or 2 GFCI's that he never had on the pump or fridge or lamp to begin with.

    Not a crawl space if he has lamps and a fridge, so probably not a "damp space or wet area". I wonder how our parents survived all those years in basements without even a ground wire on the outlets.
  10. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,559
    Location:
    North Carolina
    Didn't know that ground wires were required for these lights. Are these not the ones used by our parnets?

    Attached Files:

  11. jetlag

    jetlag New Member

    Messages:
    84
    Location:
    Ga.
    Doesnt matter if lights and frig are there , all receptacle outlets in unfinished basement , garage , or crawl space must be GFCI . Does not matter if it is wet or damp , it can be dry as a bone . Some of the parents didnt survive , because of electrocution . If the gfci has saved poeple , it is worth it .
  12. jetlag

    jetlag New Member

    Messages:
    84
    Location:
    Ga.
    Only the lucky ones that could afford keroseen in Hoover days
  13. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    I think NEC requires that lantern to be bonded to the main panel or have its own ground rod now, so its cheaper to use the un-grounded outlets.

    Also, the UBC would require automatic sprinklers, smoke alarm, and CO2 detector in any room that light is in.

    Could not be used in any public establishment by law , as the "second hand" smoke would kill the patrons.

    In California and Vermont, it would emit lead particulate and thus would subject you to a jail term.

    Also in California it may only be filled with an approved container in color and with an anti-spill spout.

    That light provided alot of work for contractors when it burned down Chicago a hundred years ago.

    Better stock up on candles before they get banned outside of churches, and entry permitted only by signing a waiver at the door.
  14. TSPORT

    TSPORT New Member

    Messages:
    46
    Location:
    Philly,PA suburbs
    Thanks for the good advice. I am just curious how what I propose is any more dangerous than just plugging a long extension cord into my generator and snaking it down the basement to hook up the sump pump in a power outage. I am 100% for safety so will likely go with the 120V gfci set-up recommended. The thing is, I already have a nice 4 prong 20amp generator cord set and a matching male flanged inlet and was hoping I could utilize the items on hand. Just my own version of a hard-wired extension cord. - TSPORT
  15. jetlag

    jetlag New Member

    Messages:
    84
    Location:
    Ga.
    You can use one of the hots on the cable you have for one GFCI and only connect to one hot neutral and ground in the inlet . I just didnt figure you would want to waste the other hot on the 220 . why dont you run another recep from the inlet box somewhere else and connect it to the other hot , that might not need gfci , depending on where you put it , you can share the neutral in the inlet box .
  16. TSPORT

    TSPORT New Member

    Messages:
    46
    Location:
    Philly,PA suburbs
    I decided to heed the advise on the GFCI and revamped my project. Went with a 125V inlet receptacle in the garage for a regular extension cord to the generator when in use. The receptacle is hard wired to a GFCI outlet in the basement. Already had the 12/3 WG run so I just capped off the extra conductor. All tested and working properly.
    Thanks guys - TSPORT
  17. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,048
    Location:
    Cave Creek, Arizona
    Maybe you should just do what 95% of people would, and install your wiring without asking for permission, assuming YOU know what you are doing.
  18. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,559
    Location:
    North Carolina
    As a side note in some cases your home insurance company can come after you for work that is not inspected in the event something goes wrong.
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