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RonRN18's avatar
RonRN18
Explorer
Apr 19, 2019

"Open Ground" from generator

I picked up my new trailer today, a Mesa Ridge 2410RL. After playing with towing and backing of the trailer, I started my first modification, installing a Progressive Industries EMS-HW30C hardwired Electrical Management System. It turned out to be a little more complicated than I originally expected because one of the Romex cables for one circuit was too short, preventing me from pulling the circuit breaker/fuse box out very far (I'm guessing they must have wired it before the side walls were in). I ended up having to pull the grill off the furnace, which gave me access into the space behind the breaker/fuse box. Once I had everything secured, I wanted to test it out. I do not have a 30-amp circuit with an RV outlet at my house, but I had purchased a Champion Model #100524 3500 Watt dual-fuel generator from Sam's Club and got it up and running. I plugged the trailer into the generator and came inside. The EMS unit was reporting an "E2" for "Open Ground" in the wiring and would not power up the trailer. I then decided to pull out an extension cord to plug the trailer into a 15-amp house outlet with an adapter. It now showed "E0" for no errors and a second or so later, the trailer was powered. This tells me that the "Open Ground" is specific to the generator. I'm curious if anyone has any first-hand knowledge as to this issue. Could it be that the generator needs to be grounded? Do I need to get a copper spike and a ground strap attached to the generator?
  • pianotuna's avatar
    pianotuna
    Nomad III
    Apr 19, 2019
    Hi,

    Generators have a floating neutral.

    You can correct it by adding a "bonding plug" on the generator.


    The easiest way to do a N-G Bond is to create a N-G Bonded Edison Plug, this is done by simply buying a replacement male plug and wiring the Neutral (White Wire/Silver Screw) to the Ground (Green Wire/Green Screw) using a 12-14 Gauge piece of wire. Just make darn sure you don’t wire the Hot leg tot he ground. Then when you need to power something like a RV or HE Furnace with your generator you plug it into a empty outlet.


  • sgfrye's avatar
    sgfrye
    Explorer
    Apr 19, 2019
    i have had the same generator as yours for almost 2 years. great generator. our first TT was 30 amp with progressive ems 30amp system. had the same code. talked to champion tech support which is great. they explained why i was getting the code. bonding plug mentioned should work but honestly ive used the generator many times with no ems and never had a problem. YMMV is my disclaimer. the generator now runs our current TT which is 50 amp. 15k btu a/c even on propane (not in economy mode) with no problems. generator on gas will produce more wattage. we just don't run anyother high draw applicances like microwave at the same time.
  • SoundGuy's avatar
    SoundGuy
    Explorer
    Apr 19, 2019
    pianotuna wrote:
    Generators have a floating neutral.


    Some do, some don't, depending on the manufacturer's intended use for that genset.

    pianotuna wrote:
    You can correct it by adding a "bonding plug" on the generator.


    You really don't have an "open ground" as your EMS is telling you, it's really a floating neutral. Bonding the genset's neutral to ground is the solution.
  • SoundGuy's avatar
    SoundGuy
    Explorer
    Apr 19, 2019
    sgfrye wrote:
    ... bonding plug mentioned should work but honestly ive used the generator many times with no ems and never had a problem.


    Of course it works, it's not the trailer that cares whether the genset has a floating neutral or not, it's the EMS.
  • Bobbo's avatar
    Bobbo
    Explorer II
    Apr 19, 2019
    pianotuna wrote:
    Hi,

    Generators have a floating neutral.

    You can correct it by adding a "bonding plug" on the generator.


    The easiest way to do a N-G Bond is to create a N-G Bonded Edison Plug, this is done by simply buying a replacement male plug and wiring the Neutral (White Wire/Silver Screw) to the Ground (Green Wire/Green Screw) using a 12-14 Gauge piece of wire. Just make darn sure you don’t wire the Hot leg tot he ground. Then when you need to power something like a RV or HE Furnace with your generator you plug it into a empty outlet.



    This is the answer ^^^^^^^^^^^^^^^^^.

    SoundGuy wrote:
    You really don't have an "open ground" as your EMS is telling you, it's really a floating neutral.

    You can ignore the sematics lesson here. What you call it really doesn't matter.

    SoundGuy wrote:
    Bonding the genset's neutral to ground is the solution.

    But, he still agrees that pianotuna's solution is the correct one.
  • ktmrfs's avatar
    ktmrfs
    Explorer II
    Apr 19, 2019
    yup, goes back to NEC code that says neutral and ground should only be bonded at the main panel, no where else downstream. So, since a trailer is meant to be plugged in downstream of the main panel, ground and neutral are NOT to be bonded in the trailer.

    And most stand alone generators also don't bond ground and neutral for safety reasons.

    So, yes an EMS will detect the"fault". And the solution is to either have a bonding plug in the generator or turn off the EMS.
  • kmac7800's avatar
    kmac7800
    Explorer
    Apr 19, 2019
    You can also use the switch on the display unit of the Progressive EMS to "ignore" this issue because you are using a generator.

    Just a thought.

    Have fun!

    //KMac
  • SoundGuy's avatar
    SoundGuy
    Explorer
    Apr 19, 2019
    SoundGuy wrote:
    You really don't have an "open ground" as your EMS is telling you, it's really a floating neutral.


    Bobbo wrote:
    You can ignore the sematics lesson here. What you call it really doesn't matter.


    Of course it "matters" as in any other situation an "open ground" is an entirely different problem than a "floating neutral". :S And BTW, in the interest of accuracy it's spelled "semantics". :W

    SoundGuy wrote:
    Bonding the genset's neutral to ground is the solution.


    Bobbo wrote:
    But, he still agrees that pianotuna's solution is the correct one.


    Of course, why wouldn't I as a bonding plug at the generator output is the correct solution to this problem. Either that or don't use the EMS when powering from a genset.
  • Ron3rd's avatar
    Ron3rd
    Explorer III
    Apr 19, 2019
    ktmrfs wrote:
    yup, goes back to NEC code that says neutral and ground should only be bonded at the main panel, no where else downstream. So, since a trailer is meant to be plugged in downstream of the main panel, ground and neutral are NOT to be bonded in the trailer.

    And most stand alone generators also don't bond ground and neutral for safety reasons.

    So, yes an EMS will detect the"fault". And the solution is to either have a bonding plug in the generator or turn off the EMS.


    Correct, and as others have explained it, the trailer is basically seen as a sub panel and sub panels don't have the neutral/ground bond which is only done at the main panel.

    I've never really thought about the issue because although I have a Progressive EMS, I've never used it with my Honda generator.
  • Bobbo's avatar
    Bobbo
    Explorer II
    Apr 20, 2019
    SoundGuy wrote:
    And BTW, in the interest of accuracy it's spelled "semantics". :W

    You are absolutely correct. Thank you.

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