How to Ground an Inverter in a Van or RV: What's Required
Grounding an inverter correctly is one of the most misunderstood aspects of van electrical systems. Get it wrong and you create shock hazards, nuisance GFCI trips, or equipment damage.
Two different grounds
DC ground (negative DC return): The inverter's negative DC terminal connects to your main negative bus bar, which connects to chassis ground. This is the return path for 12V power. Standard practice — no ambiguity here.
AC chassis/equipment ground: The inverter's chassis (metal case) should be bonded to the vehicle chassis. This ensures that if the AC output's hot wire ever contacts the inverter's metal case, the fault current has a path to ground — tripping a breaker or GFCI rather than energizing the chassis with 120V.
Neutral-to-ground bonding
In a standard 120V AC system, the neutral and ground are bonded at the source — in a house, this is at the main panel. In a van with a standalone inverter, the inverter's AC output is the source.
For a standalone inverter: Most inverters create the neutral-to-ground bond internally. The AC output neutral and ground are connected inside the inverter. Your downstream outlets, fuse panel, and GFCI outlets all work correctly from this single bond point.
Do not add a second neutral-to-ground bond at a distribution panel or outlet. Two bond points create a ground loop — ground loop current can trip GFCIs, create humming in audio equipment, and in some cases create a shock hazard.
For an inverter/charger (MultiPlus, etc.) with shore power: When shore power connects, the neutral-ground bond should come from shore (the campground's source). The inverter/charger may have a neutral-to-ground relay that opens when shore power is detected — Victron MultiPlus units do this automatically. This is correct behavior and why the MultiPlus transfer switch is more than just a relay.
Practical wiring
Battery positive → [fuse] → Inverter DC+
Battery negative → Inverter DC- → Bus bar → Chassis bolt
Inverter AC output → [distribution panel/outlets]
Hot (black) → panel breakers → outlet hot
Neutral (white) → outlet neutral (no additional bond)
Ground (green) → outlet ground → chassis bolt
The ground and neutral come from the inverter and stay separate from chassis ground in the AC distribution — they only meet at the inverter's internal bond point.
GFCI outlets
Install GFCI outlets (or a GFCI breaker) on all 120V outlets in the van. GFCI protection is required by NEC for areas near water (kitchen, bathroom) and is good practice everywhere in a van. The single neutral-to-ground bond at the inverter allows GFCI to function correctly.
Don't skip the chassis ground bond
The AC equipment ground (green wire from inverter chassis to van chassis) is a shock protection conductor. If the AC hot wire inside the inverter ever contacts the inverter case, this bond ensures fault current flows to ground and trips a GFCI rather than energizing the van body with 120V.