When removing old panel, labelled a bare wire to the frame as 12V.Having my doubts.Is it 12V or 120V ground?I suspect it is a needed 120V ground. My mental picture is a loose 120 hot wire laying on the frame.Like the old, the new panel is has a 120 to 12 converter and circuits in both voltages.The electric brakes use the frame as the neutral wire. The onboard 12V items have white neutral wires. Seems like the 120V stuff would need the metal frame grounded. My simple mind would prefer the 120 system, the 12V onboard stuff and the 12V from the tow vehicle all be separate. My inclination is to ground the 120V to the frame, leave the 12V onboard things ungrounded, and cross my fingers the 12V from the truck isn't harmed by using the grounded frame as the neutral wire.Advice please.Mike

My electrical panel has a bare wire for the 120v safety ground and an insulated wire for 12v ground. Both tie to the same ground lug on the frame.

rjxj wrote:Mine are black and insulatedThat's a danger. Ground Should be green, bare or at least white, can't see any good reason for a black ground wire.

Both should be grounded to frame of RV. I don;t like the use of black for ground either. It's counter to what the vast majority of RV's use and could be easily mistaken for something else.

Yes both 12v and 120v ground to the frame. The TT brakes use the frame as the neutral but hopefully the TT is not plugged in while it's going down the road....One of the hazards of RV wiring is the mix of 120v residential and 12v automotive. In 120v residential, the wiring standard is black/red/any color is hot, white is neutral and green/bare is ground. In 12v auto, the standard is white/any color is hot, black is neutral, no separate ground needed. So Black can be either hot or neutral depending on whether it's on the "high side" or "low side" wiring.

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krobbe
Explorer
Sep 02, 2017

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seaeagle2
Explorer
Sep 02, 2017
Marine 12Volt has gone to green with yellow stripe or yellow for ground to eliminate the is it a 120 hot or 12v ground issue.
mjeggum
Explorer
Sep 02, 2017
Thanks for all the thoughtful responses.
Good stuff.
My new wfco 8735 has no specific ground wire. All you get to deal with is a bunch of clearly described wires (battery, several hots, 1 bigger white neutral), coming out of the sealed back of the 12v circuits.
Thanks again.
Mike
beemerphile1
Explorer
Aug 23, 2017
Both 12vdc and 120vac are grounded to the chassis/frame.
Happyemptyneste
Explorer
Aug 23, 2017
What KD4UPL said!!! Exactly.
KD4UPL
Explorer
Aug 23, 2017
You're thinking too hard. The bare or green wire of the 120v should be hooked to the frame. So also the 12v negative wire should be hooked to the frame. It's the same ground.
BurbMan
Explorer II
Aug 22, 2017
Yes both 12v and 120v ground to the frame. The TT brakes use the frame as the neutral but hopefully the TT is not plugged in while it's going down the road....

One of the hazards of RV wiring is the mix of 120v residential and 12v automotive. In 120v residential, the wiring standard is black/red/any color is hot, white is neutral and green/bare is ground. In 12v auto, the standard is white/any color is hot, black is neutral, no separate ground needed.

So Black can be either hot or neutral depending on whether it's on the "high side" or "low side" wiring.
ScottG
Nomad
Aug 22, 2017
Both should be grounded to frame of RV.
I don;t like the use of black for ground either. It's counter to what the vast majority of RV's use and could be easily mistaken for something else.
GordonThree
Explorer
Aug 22, 2017
rjxj wrote:
Mine are black and insulated

That's a danger. Ground Should be green, bare or at least white, can't see any good reason for a black ground wire.
azrving
Explorer
Aug 22, 2017
Mine are black and insulated