Installation Guide

How to Install a Victron Inverter

A practical walkthrough of installing a Victron inverter in your RV — planning, sizing, cabling, safety and configuration.

Installing a Victron inverter is a significant upgrade that transforms how you use power on the road. This guide walks through the professional installation process, the safety considerations, and the best practices that keep a system running reliably for years. Prefer we do it for you? See our Victron installation service.

Planning Your Installation

Proper planning is the difference between a system that works for years and one that gives trouble. Before buying equipment or starting work, get clear on your power requirements and system design.

Calculate Your Power Needs

Start by listing every AC appliance you plan to run from the inverter:

Microwave ovens (typically 800–1,200W)
Coffee makers (600–1,200W)
Hair dryers (1,200–1,800W)
Laptops and phone chargers (50–100W each)
TV and entertainment systems (100–300W)
Kitchen appliances (variable)

Choosing the Right Size

Your inverter should be sized for your largest single appliance plus 20–30% headroom. For most RVs, a 2,000–3,000W inverter is versatile. Remember that starting loads — microwaves, power tools — can spike to 2–3× their running wattage.

Popular Victron Models for RVs

MultiPlus 12/2000: good for smaller campervans and caravans with modest needs.
MultiPlus 12/3000: the popular choice for full-size motorhomes and larger RVs.
Quattro series: for those needing dual AC inputs (shore power + generator).
Phoenix inverters: a standalone inverter option where charging is handled separately.

Tools & Materials

The right tools make for a professional, safe installation:

Torque wrench

Multimeter

Drill & bits

Cable crimpers

Wire strippers

Heat gun

Essential Materials

Battery cables: sized to the inverter's spec (typically 4 AWG or larger for 2,000W+ systems).
Fuses / circuit breakers: properly rated (ANL fuses or MRBF breakers recommended).
Battery terminals: quality crimp-on lugs rated for your cable size.
Heat-shrink tubing: marine-grade, for weatherproofing connections.
Mounting hardware: stainless-steel bolts and anti-vibration mounts.
Cable management: UV-resistant ties and protective conduit.

Critical Safety Warning

Working with high-current DC and 230V AC is dangerous. If you're not confident in your electrical skills, hire a qualified RV electrician — mistakes can cause fire, equipment damage, serious injury or death. Always disconnect all power sources before starting work. In NZ, fixed 230V work must be done by a registered electrician.

Safety Guidelines

Disconnect everything: shore power, solar, generator and battery connections.
Use proper PPE: insulated gloves, safety glasses, non-conductive footwear.
Double-check polarity: reversing DC polarity will instantly destroy the inverter.
Ventilation: inverters generate heat and need adequate airflow.
Fire extinguisher: keep a suitable extinguisher nearby during installation.
Follow AS/NZS standards: comply with local electrical codes for mobile installations.

Step-by-Step Installation

Choose the Location

Pick a spot that's as close to the battery bank as possible (shorter cables = less voltage drop), well-ventilated, protected from moisture and road spray, accessible for maintenance, on a secure surface that handles vibration, and away from sleeping areas (inverters make noise when running).

Mount the Inverter

Victron inverters mount vertically for optimal cooling. Use the mounting template to mark holes accurately, secure with stainless-steel bolts, and consider anti-vibration mounts to reduce stress during travel.

Size & Install DC Cables

The most critical step. Cable size depends on the inverter's maximum current draw, the cable length from battery to inverter, and keeping voltage drop under about 3%. A 3,000W 12V inverter can draw around 250A, so cabling is crucial — most installs need 4/0 AWG or larger for runs over ~1.5m.

Cable Sizing Example

A 3,000W MultiPlus 12/3000 with a ~2m cable run: use 4/0 AWG (107mm²) to keep voltage drop under 2%. Never use automotive battery cable — it isn't rated for continuous high current.

Install Overcurrent Protection

Every inverter install must have a fuse or breaker on the positive cable, close to the battery. For a 3,000W system, use a 300–400A ANL fuse or MRBF breaker. This protects against catastrophic cable failure and is required by electrical codes.

Make the DC Connections

With all power disconnected: crimp quality terminals with proper crimpers, apply heat-shrink for weatherproofing, connect the negative first (reduces spark risk), then the positive through your fuse/breaker, torque to spec, and apply anti-corrosion compound.

Polarity Check

Before connecting to the inverter, triple-check polarity with a multimeter. Connecting backwards destroys the inverter instantly and voids the warranty. Red = positive, black = negative. No exceptions.

AC Wiring

The 230V side needs care: connect shore-power input to your RV's inlet (for a MultiPlus/Quattro), wire the AC output to your distribution panel or dedicated outlets, connect to the RV's AC ground system, and install appropriately rated breakers. On integrated systems, the Victron switches automatically between shore power and inverter power. This 230V work must be carried out and certified by a registered electrician in NZ.

Power Up & Configure

Once everything's secure: re-check all connections, verify battery voltage is in range, switch the inverter on, check for error codes, then use the VictronConnect app (Bluetooth or VE.Direct) to configure settings.

Test & Optimise

Run various appliances to confirm operation, listen for unusual noise or vibration, monitor battery voltage under load, test automatic transfer switching (if fitted), and adjust settings for best performance.

Configuration Tips

The VictronConnect app unlocks the inverter's full potential. Key settings to get right:

Battery type: set correctly for your chemistry (AGM, lithium, gel).
Charging parameters: absorption voltage, float voltage and charge current.
AC input limits: set current limits so you don't trip campground breakers.
PowerAssist: lets the inverter boost limited shore power with battery power.
Low-voltage cutoff: protect the batteries from over-discharge.
Remote monitoring: set up VRM for internet-based monitoring.

PowerAssist

A game-changer for RVers: it lets the inverter supplement limited shore power, so you can run high-draw appliances on a small connection without tripping breakers — the inverter adds battery power automatically when needed.

Common Mistakes to Avoid

Undersized cables — cause voltage drop, overheating and fire risk.
Missing overcurrent protection — dangerous and non-compliant.
Poor ventilation — don't install in a sealed compartment.
Loose connections — high-current terminals must be torqued properly.
Ignoring polarity — always double-check before powering on.
Wrong battery settings — incorrect charge profiles damage batteries.
No monitoring — fit a battery monitor to track system health.

Prefer to Have It Done for You?

Inverter installation involves high-current DC and 230V AC work. If you'd rather leave it to the experts, we design and install Victron systems professionally at our Christchurch workshop — sized, wired, certified and commissioned.

See Our Installation Service Book an Enquiry

This guide is general information to help you understand the process, not specific electrical advice for your vehicle. In New Zealand, fixed 230V work must be carried out and certified by a registered electrician — always have inverter and 230V installation done to AS/NZS standards.