What happens if I bridge L1 and L2 on a 120 genset

Discussion in 'Electrical Forum discussion & Blog' started by chefwong, Dec 1, 2012.

  1. chefwong

    chefwong New Member

    Messages:
    710
    Location:
    District of Columbia
    Dual EU2000i.
    To power a 220 on the transfer switch.
    Power is enough on the genset.

    Will a cheater cord of L5-30P coming off the genset to a L14-30 with L1 and L2 Bridge going back to the transfer switch be OKAY - as long as I'm withing the power capabiities ?

    So the Genset cable from Genset to Transfer Inlet - 5-30P to L14-30 would be
    1 Hot to L1/L2 on the Inlet side.
    Last edited: Dec 1, 2012
  2. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,136
    Location:
    Houston, TX
    The Breaker will Pop ?

    Try it and give us a report.

    I would like to know.
  3. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    You can do it, just make sure you disable any 240V loads powered by the transfer switch.

    Also, it is an L14-20 female cap you need, not L15-20.
  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,013
    Location:
    New England
    We may be misunderstanding the terms, but if you have any common neutral circuits, you could easily overload the neutral and potentially burn something up. This could happen if you used x-3 to power two circuits where the neutral is common via a dual-gang breaker. ANd, obviously, it wouldn't work if there were any 240vac circuits.
  5. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,136
    Location:
    Houston, TX
    Doing something like this could produce Smoke.

    Please post your Video.

    Why not get the proper equipment and do it safe and correct ?
  6. chefwong

    chefwong New Member

    Messages:
    710
    Location:
    District of Columbia
    I bought 2 eu2000 Gas Sipping Gensets.
    I don't expect to use them except maybe every 2-3 years....
    I do plan to excercise them though.

    I don't need a genset that uses 3-6 gallons a day .
    The defeated the whole purpose for ~my needs~.

    Hence the 2 gas sipping inverters.

    I'm not opposed to a 220 genset IF I need it for the 220 application.

    But for all intents and purposes, I was just checking in to see if bridging the L1/L2 on the plugs so the transfer switch sees the 220 load....would it Work or what issues are there from a safety standpoint if I do it this way.
  7. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,982
    Location:
    NW Ontario, Canada
    The issue that Jim mentioned is that a "split" could be wired with the neutral sized to only half the max load and with both legs going to the same source, the neutral could carry twice as much as it was rated for.

    Some people setup a separate sub-panel for critical circuits with a manual X-fer switch to power it from a 110/120V genset.
  8. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    Doing this will not give you a 220 volt anything nor will anything see 220
  9. chefwong

    chefwong New Member

    Messages:
    710
    Location:
    District of Columbia
    Got it.
    So for now, I'll use put 110 items on the transfer.

    The transfer switch has 2 legs.
    It's at least OKAY to still make the cord with L1/L2 bridged so that the transfer switch is seeing power right ?
    I plan to put a linesman *decal tag* on the cord to identify that L1/L2 has been bridged
  10. big2bird

    big2bird IBEW Electrician

    Messages:
    141
    Location:
    Anaheim, Ca.
    I would not, and frankly, I am deeply concerned that you even asked.
  11. chefwong

    chefwong New Member

    Messages:
    710
    Location:
    District of Columbia
    Why not.

    I plan to install the outside inlet once, so future-proofing with the 120/220 on the box + the switch is fine.
    As long as I'm not tying any 220 to the switch, and to get 120 to both legs of the switch, L1 and L2 needs to be bridged.
    The breaker on the genset will pop ......

    So where is the issue here ?

    It doesn't make sense to just buy 120 switch only to reinvent the wheel and buy a new switch, inlet, etc IF there is a possibility of me feeding it 220 down the road.

    For now, I am sticking with the EU2K for it's FUEL Sipping capacity. I probably will end up using only 1, but I have the 2nd as a backup as well as a parallel unit.
    Last edited: Dec 1, 2012
  12. big2bird

    big2bird IBEW Electrician

    Messages:
    141
    Location:
    Anaheim, Ca.
    Parallel unit? As in at the same time?
  13. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,013
    Location:
    New England
    Many gensets cannot be run in parallel - they must remain in sync - exactly, or things go wonky. Only if they are designed for it, and are setup properly, can this be done.
  14. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    No transfer switch for this generator just use cords from the receptacle on the generator to the load.

    No ---the breaker will not pop-----the damn generator will pop.

    STOP!!!!!!!!!!! What you are planning is dangerous and deadly.
  15. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    GUYS! I know everyone is justifiably up in arms about this, but the Honda EU2000 is specifically designed to run in parallel with two units and a wiring kit from Honda.

    All he wants to do for now is jump out L1 & L2 to feed the GEN side of the transfer switch. NOTHING will produce smoke as long as the 240V loads are turned off, and it is NOT dangerous. It is ill advised as 2000 watts is a tiny amount and the gen breaker will definitely trip from time to time, but it is not unsafe.
  16. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    Several things come into play with these generators. The size generator that you have chosen will only deliver 120 volts at 1600 watts which is little power.

    This type generator can also be used with a companion generator but that companion generator must be a designated generator and not just any old generator will work. Not even two of the same make and model will work together it must be a companion generator.

    When two are connected together you will still only have 120 volts. There is no way to achieve 240 volts using two at one time. To jumper from one leg to the other leg in order to make both sides of the panel hot is a very bad idea and even dangerous.

    Under full load this little box will go through a tank of fuel in about 2 ½ (from experience) hours and when two are being used the fuel use doubles. Not much savings when two small generators are being used in the place of one larger one.

    In order to be installed in a code compliant manner they must be connected to the premises wiring through a transfer switch that switches the neutral or they must be connect to the premises wiring as a Separately Derived System.

    These types of generators are designed to be used with cords. In order to save money and I think that is the purpose of using one of these, plugging a cord into the receptacle of the generator and into the load being used is the proper method of use.

    If it is your intention to use one of these for heat you might want to rethink your design and spring for something of value like a 30kw type generator. Unless you heat with gas or oil this little bugger will not be of much help and if you do have gas or oil it will be all that little box can do to start the fan motor to running if it will start it at all. It will take about 4000 watts to start a ½ HP 120 volt motor which is more than two of these units will pull.

    Then we come to the best part, the warranty. Unless this generator is installed and used according to its listing and labeling then the warranty is void. For more information to the listing of this generator see UL White Book FTCN. The information about the warranty voidance can be found in the equipment manual.
  17. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,136
    Location:
    Houston, TX
    I Don't understand why you would want to connect a Inverter to 2 circuits when it will barely power 1 circuit.

    You should get a Real Generator if you go thru the trouble of putting in a transfer switch.

    You could have bought a Good Gasoline or NG Generator that puts out 240 for what you paid for them 2 Honda Play Toys.

    Were they on Backdoor Special ?
  18. chefwong

    chefwong New Member

    Messages:
    710
    Location:
    District of Columbia
    Noise, portability, Fuel.

    The EU is fine for the current application.
    My home in NC in the sticks has a propane fueled generac but that is the Right genset for the application.

    For my primary residence, I get a brownout -- maybe once every year in the summer. Anywhere from 45 minutes to maybe 3-5 hours ? The last power outage aside from Sandy was the great Northeast blackout.

    So these small sipping gensets use less fuel. I can run LEAN to run the stuff I need to . I'll let it throttle to 3600 RPM when full and it will just idle back when it needs to.

    Bigger is not necessarily better given the application. I don't look at how many W per $ I am getting when looking at the APPLICATION for this genset.
    I have a friend who has both a small inverter and a big diesel. Even with a 2 week outage, he will run his single 2K inverter and then run the diesel to run the well, etc.
  19. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,136
    Location:
    Houston, TX
    Sounds like you have a plan.

    That type of Generator is good for what it is designed for. It is Overrated when it come to continuous full load use.

    I think Charging a battery would be good for when you run out of fuel then you can at least have lighting.

    Good Luck.

    Be careful playing with electricity, It can be a shocking experience.
  20. cwhyu2

    cwhyu2 Consultant

    Messages:
    1,347
    Location:
    Cincinnati OH
    I have a brand new 18000 k/w B&S sitting at the shop that wants a home.It can run N/G or propane transfer switch included.
    Last edited: Dec 4, 2012

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