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Blackdiamond's avatar
Blackdiamond
Explorer
Jul 06, 2015

New Inverter Charger, wiring question

I just installed a new inverter/charger with an automatic transfer switch and it appears to be working properly but I am confused on the ground wiring and want to make sure I don't have a problem down the road.

The old converter/charger had a ground wire connected to the frame yet the negative side of the batteries are also connected to the frame, so I connected the new inverter the same way.

My question is...is that the common and correct way to wire these? My concern is when the time comes to plug in something to the inverter circuit that requires a ground (3 prong plug) there might be issues.

The other question I have is I just unplugged the old converter charger and left it and the wiring in place, will that cause any issues?

10 Replies

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  • brulaz's avatar
    brulaz
    Explorer
    Oct 22, 2015
    dstr_59 wrote:
    I too am installing an inverter(1500 watt, no charger).
    my directions say to use the same gauge wire to run the ground for the unit, as used for the dc input wiring. In my case that's 1/0 wire min.
    yet they expect me to connect it thru a mere 10-32 terminal. really ???
    my input wiring, positive and neg, connect thru a 5/16 stud.
    unit is a intertek (nature power).


    Worse situation here.

    My 1000W inverter instructions make zero reference to chassis ground. Not in the diagrams or the text.

    But on the case there is a tiny 5/32" bolt that looks like it could be the inverter's case ground and is connected according to my ohmmeter to the inverter's AC output ground, which in turn is connected to the chassis via the permanent 12ga AC line leaving the inverter.

    Is this case ground to Inverter AC ground to chassis ground sufficient?

    Attaching a 12ga or bigger cable to that tiny 5/32" bolt just doesn't seem right.
  • time2roll's avatar
    time2roll
    Nomad
    Oct 22, 2015
    #8 is fine for chassis ground. Prosine 1800 and GoPower 2000 both call for the same #8 wire.
  • Salvo's avatar
    Salvo
    Explorer
    Oct 22, 2015
    I would disconnect the old converter output. When connected, it will pull current from the battery forever. Why
  • dstr_59's avatar
    dstr_59
    Explorer
    Oct 22, 2015
    I too am installing an inverter(1500 watt, no charger).
    my directions say to use the same gauge wire to run the ground for the unit, as used for the dc input wiring. In my case that's 1/0 wire min.
    yet they expect me to connect it thru a mere 10-32 terminal. really ???
    my input wiring, positive and neg, connect thru a 5/16 stud.
    unit is a intertek (nature power).
  • Blackdiamond's avatar
    Blackdiamond
    Explorer
    Jul 06, 2015
    Thanks everyone!!!!Glad to know I am okay, this thing was a pain to wire due to the limited space and tight wire runs.
  • Blackdiamond's avatar
    Blackdiamond
    Explorer
    Jul 06, 2015
    MrWizard wrote:
    he has a spare charger/converter

    yes ground to the frame with the Ground lug

    but run a NEG wire all the way to the batteries
    do not use the frame for the negative path

    do not ground the inverter to the NEg cable/the batteries
    the negative power path and the safety ground/frame path
    are two separate physical and electrical paths
    never mine that they will read continuity with a meter
    they are individual physical circuits
    connecting the inverter ground to the NEg cable/battery can induce AC into the DC path
    it also removes the safety factor.. the safety factor to be real the ground is frame ground, not battery negative


    Just to clarify; Neg (and pos)cable from new inverter is going directly to the battery, ground from inverter is going to frame, same place as old charger, neg from house batteries are going to frame.
  • time2roll's avatar
    time2roll
    Nomad
    Jul 06, 2015
    Yes the chassis ground is correct to the frame and should be independent of the B- connection.
    This keeps the unit grounded during service of the 120v, the battery or battery connection.
    The idea is that for safety it is better for a fault to be conducted by the wire instead of a person.

    No issues with the old unit sitting unplugged ready to go if needed.
  • MrWizard's avatar
    MrWizard
    Moderator
    Jul 06, 2015
    he has a spare charger/converter

    yes ground to the frame with the Ground lug

    but run a NEG wire all the way to the batteries
    do not use the frame for the negative path

    do not ground the inverter to the NEg cable/the batteries
    the negative power path and the safety ground/frame path
    are two separate physical and electrical paths
    never mine that they will read continuity with a meter
    they are individual physical circuits
    connecting the inverter ground to the NEg cable/battery can induce AC into the DC path
    it also removes the safety factor.. the safety factor to be real the ground is frame ground, not battery negative
  • Ivylog's avatar
    Ivylog
    Explorer III
    Jul 06, 2015
    Where else are you going to find a ground on something that moves? So, yes that is correct. Sounds like you'll have a spare inverter that will be easy to hookup if this one gives trouble.

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