MultiPlus-II 12/3000/120-50 120V

Victron MultiPlus-II 12/3000 120V

Name: Victron MultiPlus-II 12/3000 120V
Brand: Victron

Single 120 V AC MultiPlus-II: 3000 VA / 2400 W at 25°C, 120 A charger and 50 A transfer switch, with a 12 V DC house-bank connection. The 230 V and 2x120 V versions are different models. DC draw and surge values below are planning estimates; verify actual operating conditions.

Use this component in Crimp Show sizes in AWG

The reference run on this page is 3 m one way, sized against ABYC E-11. Your own run will differ, and the canvas sizes that one.

Wiring diagram

How the MultiPlus 3000 is wired.

The drawing shows where the feed, the return and the fuse land on this part. The starter uses the same reference circuit and sizing assumptions. Read the installation notes for manufacturer requirements before adapting the runs.

House bank +
positive connection
120 mm² (4/0 AWG) · 400 A fuse
3 m one way · 215 A design
To MultiPlus 3000 DC +
House bank −
negative connection
70 mm² (2/0 AWG) · unfused return
3 m one way · 215 A design
To MultiPlus 3000 DC −

Single-path calculation only; parallel cables require manual review.

Victron MultiPlus-II 12/3000 120V: 2 DC connections from the same editable starter, with individual feed, return and supply-lead assumptions. Read the installation notes before adapting this example.Single-path calculation only; parallel cables require manual review.

120 V AC model, DC planning example only. The manual specifies a 400 A DC fuse and TWO 1/0 AWG cables per polarity for 0–5 m runs (two 2/0 AWG for 5–10 m), with 90°C copper and no closed conduit. Crimp currently calculates each drawn path as one conductor; its displayed wire is NOT a verified substitute for that parallel pair. The starter uses a 400 Ah placeholder bank and pins the manual's fuse rating. Review the bank, actual fuse/holder, disconnect and parallel-cable design separately. AC wiring and surge duration are not verified here. Manufacturer installation manual

Open starter in Crimp

Build it out

Build the system it goes in.

Open the canvas with MultiPlus-II 12/3000/120-50 120V already placed, then add your batteries, charging, distribution and loads around it.

Every cable you draw there is sized against ABYC E-11, from the same tables as the reference on this page.

Technical reference

Specs, terminals and the parts around them.

The catalog facts for this part, which terminal takes what, and the hardware you'll want around it. Check the nameplate on your own unit before you order.

Catalog specification

Compatible systems: 12 V
Rated power: 2,400 W
Estimated DC draw: 215 A
Rated output: 120 A
Estimated DC peak (duration unknown): 500 A

3 m reference run

12 V DC · 120 V AC model

Wire: 120 mm² · 4/0 AWG
Fuse: 400 A
Design current: 215 A
Voltage drop: 1.6%

Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. The design current is a catalog planning estimate for inverter operation at nominal battery voltage, not a measured draw. Actual current changes with load, battery voltage and efficiency; charging uses the same DC paths. The single-path cable result does not verify the manual's parallel conductors. The length is one way; voltage drop includes an equal-length return. The shared starter uses 3.048 m (10 ft) runs unless a shorter run is stated. These are example assumptions for you to adapt to your own installation.

Supporting parts

6.1 m total of 120 mm² (4/0 AWG) marine cable
Terminations for 120 mm² cable, matched to the equipment's screw terminals, leads or studs
400 A fuse and holder on the positive run
Heat-shrink, strain relief and terminal boots sized to the cable

Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.

Terminal map

This is MultiPlus-II 12/3000/120-50, single 120 V AC. DC + and DC − carry both inverter discharge and charging. The drawn DC connections are logical paths, not the manual's parallel cable pairs. AC terminals are left disconnected: protective earth, AC-out-2, grounding relay behavior and AC protection are not modeled. Catalog DC current values and terminal limits are planning assumptions, not verified connector ratings.

TerminalPolarityRoleLimit

AC IN L

ac-in-l

neutral · input

neutralinput50 A

AC IN N

ac-in-n

neutral · input

neutralinput50 A

DC +

dc-pos

positive · input

positiveinput400 A

DC −

dc-neg

negative · input

negativeinput400 A

AC OUT 1 L

ac-out-l

neutral · output

neutraloutput50 A

AC OUT 1 N

ac-out-n

neutral · output

neutraloutput50 A

Field notes

How it actually goes in.

What we've read and heard about installing this exact part. These are notes, kept apart from the numbers Crimp works out.

Which MultiPlus-II 12/3000 voltage variant is this?

This page represents MultiPlus-II 12/3000/120-50, single 120 V AC, with a 12 V DC bank connection, 3000 VA inverter, 2400 W continuous output at 25°C, 120 A charger and 50 A transfer switch. See the exact column in the 120 V specifications.

The 120 inside 12/3000/120-50 is the charger current, not proof of AC voltage. The separate 2x120 V catalog model and the 230 V 12/3000/120-32 require their own manuals. Switching this page to AWG changes units, not hardware.

What DC fuse and battery cables does the manual require?

The 120 V manual, section 4.3, specifies a 400 A DC fuse and two 1/0 AWG conductors per polarity for 0–5 m; its 5–10 m row specifies two 2/0 AWG conductors per polarity. It calls for 90°C copper, excludes closed conduit, and gives a 400–1200 Ah battery-capacity range. These are model-specific installation requirements, not a fuse rule derived from amp-hours.

Crimp currently models each drawn DC path as one conductor. The displayed single-path wire result does not verify or replace the manual's parallel pair. The same limitation travels into the starter's notes. Review the physical parallel conductors, protection, disconnect and actual battery with the manual before installation.

What opens in the editable example?

A 400 Ah placeholder house bank connects to DC+ and DC−. The same paths carry inverter discharge and battery charging. The manual's fuse rating is pinned; the engine calculates the displayed single-path wire and voltage drop from the same system opened in Crimp.

The catalog's DC draw and peak values are planning estimates, not manufacturer-tested current curves. The bank's acceptance, BMS, actual low-voltage draw and surge duration remain unverified. Use the exact-fuse checker for fuse/holder and fault-current evidence; the amp rating alone cannot settle those questions.

What about AC wiring, monitoring and distribution?

This starter covers the DC connection only. AC supply, protective earth, output protection and grounding behavior require the manufacturer's AC instructions and qualified installation. The catalog's abbreviated AC terminals are not a complete mains pinout.

Use the SmartShunt example to plan the monitored return and the Lynx Distributor example for branch distribution. The conversion guide explains where charging and battery-protection checks fit into a refit.

The campervan and RV DC wiring examples cover solar, alternator charging and small loads before an inverter upgrade. They leave this MultiPlus and its AC/parallel-cable design out of scope.

Verified against the manufacturer's documentation (rev. 15 — 08/2026), checked 2026-09-11. Manufacturer documentation →

Method & provenance

What is known, assumed and computed.

The manufacturer publishes some of these numbers and Crimp works out the rest. It's worth knowing which is which.

From the maker

What the catalog says

Manufacturer, model, ratings and which terminal does what come from the catalog. A newer revision, or the nameplate on the unit in your hand, can say something different — when it does, the nameplate wins.

ABYC E-11

What Crimp worked out

Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. The run length and the current above are what drive the result. Crimp doesn't know how warm your space gets; draw the cable inside an engine-bay zone on the canvas and it sizes for the heat.

Read how the sizing works

Next step

Draw the MultiPlus 3000 into your own system.

It lands on the canvas already placed. Add what it connects to, and every run gets its wire and fuse as you draw.

Use this component in Crimp