Wiring an inverter correctly is mostly about three things: short heavy cable, the right fuse, and proper grounding. Here's the step-by-step for a US van or RV build, building on the inverters & 120V power guide.
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Step 1: Mount it close to the battery
Inverter cable carries the highest current in the system — at 2,000W, roughly 190A. Every foot of cable at that current adds cost and voltage drop, so mount the inverter as close to the battery/bus bars as the install allows, in a ventilated spot (inverters generate heat under load and need airflow).
Step 2: Run the DC cable
Size the positive and negative DC cables for the inverter's full-load current — for a 2,000W inverter, that's 2/0 AWG or larger. Both cables run from the inverter to the bus bars (not directly to the battery terminals). See the AWG wire size chart for other sizes.
Step 3: Add the fuse
A dedicated fuse goes on the positive DC cable, sized to the inverter's full-load current:
- Under ~1,000W: an ANL or MIDI fuse rated appropriately.
- 2,000W+: typically an ANL or Class T fuse rated 200-250A, placed as close to the bus bar/battery as practical.
See RV fuse sizing for the full method.
Step 4: Ground the inverter
- Chassis ground: connect the inverter's case/ground terminal to the vehicle's single chassis bonding point — the same one used for the rest of the 12V system.
- AC output ground: if the inverter feeds fixed 120V outlets, the AC ground conductor follows the same grounding/bonding scheme as the rest of the AC system, per NEC Article 551.
The AC output side needs NEC-compliant wiring
Running the inverter's 120V output to fixed outlets means that wiring — breakers, GFCI, grounding — falls under NEC Article 551. The DC input side (steps 1-3) is DIY-friendly; the AC output side should be installed or inspected by a licensed electrician.
Step 5: Add a remote switch (optional but recommended)
Inverters draw power just being switched on (standby draw). A remote on/off switch, mounted somewhere convenient, lets you fully power down the inverter when you're not using AC — without crawling to reach the unit itself.
Step 6: Test before relying on it
With the inverter wired and fused, test with a small known load (a lamp, a phone charger) before connecting anything sensitive. Confirm the battery monitor shows the expected current draw, and check cable temperatures after a few minutes under load — warm is normal, hot is not.
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