Victron Energy Autotransformer, 120/240V, 50/60Hz, IP21

Overview

The Victron Energy Autotransformer is a 120/240V autotransformer for AC systems that need step-up, step-down, or split-phase output balancing. It helps create a usable neutral and balance uneven 120V loads across a 120/240V supply, which is useful on boats with a mix of inverter, generator, shore-power, and onboard AC loads.

The range runs at 50/60Hz and is available with 32A or 100A maximum 240V feed-through current. Both versions use a toroidal transformer in an aluminium enclosure, include an input circuit breaker, carry an IP21 protection category, and measure 425 x 214 x 110 mm. Neutral current is rated at 32A for 30 minutes and 28A continuous at 40°C/100°F.

Key features

• Works with 120/240V AC systems for step-up, step-down, split-phase, stacked inverter balancing, and generator balancing configurations.
• 32A and 100A pass-through-current versions let the unit match the AC capacity of the installation without changing the core function.
• Built-in grounding relay supports split-phase systems used with Victron Multi or Quattro inverter/chargers when the inverter/charger ground relay is disabled.
• Temperature protection disconnects the autotransformer from the supply when overheating occurs, with manual reset after the fault is addressed.
• Aluminium enclosure with IP21 protection is suited to electrical spaces that stay dry and protected rather than exposed cockpit or deck locations.
• EN 60076 safety compliance, 50/60Hz operation, and toroidal transformer construction support use in permanent AC power installations.

Variants

The product is offered in two pass-through-current configurations. Both variants share the same 120/240V AC input/output voltage, 50/60Hz frequency rating, neutral-current rating, IP21 protection category, aluminium enclosure, and 425 x 214 x 110 mm enclosure size.

The main difference is the maximum 240V feed-through current and the two-pole input circuit breaker rating, so the correct selection depends on the current rating of the AC system around it.

• ITR000100001: 32A pass-through current with a 32A two-pole input circuit breaker. This keeps the autotransformer aligned with systems protected at the 32A level.
• ITR000100101: 100A pass-through current with a 100A two-pole input circuit breaker. This keeps the pass-through path aligned with installations protected at the 100A level.

Installation and setup

This is an AC power component, not a low-voltage DC accessory. It belongs in the vessel's protected electrical area with appropriate overcurrent protection, wiring size, ventilation, and grounding practices for the complete AC system. Installation should be handled by a qualified marine electrical professional, especially when the unit is used with shore power, a generator, or inverter/charger equipment.

For split-phase balancing, the autotransformer creates the neutral point rather than relying on an uneven neutral from the source. In systems using a Victron Multi or Quattro, the grounding relay in the autotransformer is used for this function while the internal grounding relay in the inverter/charger is disabled.

Use on board

This autotransformer fits vessels that need to manage 120V and 240V AC loads from a shared split-phase system, such as boats running appliances, chargers, air conditioning, or other AC equipment from a generator, shore connection, or inverter setup. It is most relevant where uneven 120V loading can leave one leg near its limit while capacity remains unused on the other leg.

Because the enclosure carries an IP21 rating, it should be treated as equipment for a cabinet, utility space, or machinery space with protection from spray and washdowns. It is not the right type of component for an exposed deck, wet locker, or location where saltwater can reach the housing.