Victron Energy 4500W Auto 115/230V Isolation Transformer, 120/240V Output, IP21

Overview

The Victron Energy ITR050452042 is a 4500W isolation transformer for boat shore power systems that need AC electrical isolation, galvanic corrosion protection, and automatic input voltage detection for 115V or 230V supplies. It accepts 115V or 230V AC input, outputs 120V or 240V AC depending on configuration, and runs at 50/60Hz.

By separating the vessel AC system from the shore-side ground, this transformer helps reduce galvanic corrosion risk on underwater metal parts such as shafts, propellers, through-hulls, and fittings while still supporting safe onboard grounding practice. It is a practical fit for cruising boats, fishing boats, and larger vessels that connect to marina shore power for charging, appliances, heating, air conditioning, and dockside AC loads.

The unit has a 38A output current rating at 115V and 19A at 230V. It uses a toroidal transformer with a 1:1.05 ratio, soft start to limit inrush current, and an aluminium enclosure with IP21 protection, so it belongs in a dry, protected technical space rather than an exposed cockpit or deck locker.

Key features

• 4500W shore power isolation for vessel AC installations using 115V or 230V supply.
• Automatic AC input voltage detection switches between 115V and 230V input ranges.
• Configurable AC output supports 120V or 240V onboard AC layouts.
• Helps break electrical continuity between shore power and the boat to reduce galvanic corrosion risk.
• Soft start limits transformer inrush current, helping prevent nuisance tripping of shore power protection.
• 38A output rating at 115V and 19A output rating at 230V for matching shore power capacity and onboard load planning.
• Toroidal transformer construction keeps weight and operating noise lower than many conventional transformer layouts.
• Aluminium blue RAL 5012 enclosure with IP21 protection for installation in a dry machinery space, electrical locker, or similar protected area.
• Operating temperature range is -20°C to 40°C with maximum 95% non-condensing humidity.
• EN 60076 safety standard, 21.8 kg weight, and 362 x 258 x 221 mm dimensions for layout and mounting checks.

Installation and setup

This transformer is installed between the shore power inlet and the vessel AC distribution system. Shore power connects to the AC input terminals, and the vessel AC loads connect to the AC output terminals. The enclosure ground is connected to the vessel grounding system, and the neutral-to-earth link on the output side is set as part of the installation so downstream GFCI protection can operate correctly.

The AC output voltage must be configured for 115V or 230V use with the included black jumper wires. Minimum cable cross-sections are 6 mm² or AWG 10 for 115V operation and 4 mm² or AWG 11 for 230V operation. AC shore power work should be handled by a qualified marine electrician because correct grounding, overcurrent protection, cable sizing, and fault protection are critical on board.

Electrical and system integration

The transformer can be used in 115V to 120V, 230V to 240V, 115V to 240V, and 230V to 120V shore power arrangements. The 1:1.05 ratio raises the AC output slightly compared with the input, which should be considered when checking compatibility with onboard AC equipment and marina supply conditions.

When the vessel is out of the water for maintenance or winter storage, the AC input earth and AC output earth can be linked inside the transformer with the included yellow and green jumper wire. This keeps the shore earth connection in place during on-land service conditions.

Use cases on board

This isolation transformer is a strong match for boats that spend regular time connected to shore power and need a clean separation between marina AC supply and the vessel electrical system. It is especially useful where galvanic corrosion control matters, such as boats with exposed shafts, propellers, metal through-hulls, or mixed underwater metals.

Because the enclosure is IP21, the installation location should be sheltered from spray, bilge water, washdowns, and direct weather exposure. Plan for the 21.8 kg weight, airflow around the enclosure, and access to the terminals and jumper positions during installation and inspection.

What’s included

• 1 isolation transformer
• 1 hanging bracket for mounting inside a vessel
• 1 long yellow and green jumper wire with female 6.35 mm spade connectors for linking AC input earth to AC output earth when the vessel is out of the water
• 1 long yellow and green wire with eye terminals for case grounding
• 1 short yellow and green jumper wire with female 6.35 mm spade connectors for the AC output neutral to earth link
• 4 short black jumper wires with 6.35 mm female spade connectors for AC configuration
• 7 mounting screws

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