Victron isolating transformer 120/240V-100A

The 100A isolation transformer from Victron Energy (MPN: ITR000100101) offers an efficient solution for balancing upward, downward, and split phase outputs in power supplies. With a rating of 120/240V and a maximum current of 100A, it is particularly suitable for applications where different loads occur on your 120/240V circuits. The autotransformer absorbs this asymmetry to utilize the maximum available power while ensuring stable operation. In addition, the transformer is equipped with an integrated grounding relay and protects against overheating by automatically shutting down, ensuring safety and ease of use. Whether as an alternative to coupled inverters such as the MultiPlus or Quattro, or to optimize existing systems, the autotransformer is a valuable addition to any electrical installation.

Product information about the isolation transformer

• Alternative to coupled inverters
• Compensation of upward, downward, and split phases
• Transformer type: Toroidal
• Temperature protection, overcurrent protection
• Versatile application options
• Safe installation and cabling

When operating with inverters/chargers

In inverter mode, it is crucial that the neutral conductor of the inverter/charger is connected to the ground to ensure the proper functioning of a GFCI (ground fault circuit interrupter). This reduces the risk of electric shock or fire. In the case of a split-phase supply, the neutral conductor must also be grounded. For this purpose, the autotransformer has an integrated grounding relay that is controlled by the 230/240V Multi or Quattro. To ensure optimal operation, the internal grounding relay of the 230/240V Multi or Quattro must be deactivated.

Types of use

Compensation - An autotransformer is particularly useful for utilizing the full power of a split-phase source such as a generator or connected inverters. Often, a single-phase load cannot draw more power even though a circuit is not fully utilized. The autotransformer solves this problem by creating a new neutral conductor and balancing unbalanced loads with the help of the autotransformer. The two circuits of an autotransformer operate independently of each other, except that there is a fixed phase shift of 180 degrees. This ensures that the sine waves run in opposite directions, creating double the voltage between the circuits.

Increasing the voltage - Deep well pumps and air conditioning systems often require a split phase of 120/240 VAC. If the available power source does not meet the requirements, a step-down transformer can double the input voltage. Instead of connecting two 120 VAC inverters, it is recommended to use a single 120 VAC inverter together with a step-up transformer.

Voltage reduction - In installations that use a split-phase generator and a single-phase inverter, an autotransformer can be used to reduce the voltage. It allows optimal use of the total available power from both circuits of the generator to supply loads and charge batteries. If the available AC source is insufficient, it regulates the voltage to the required level.

Grounding relay - In TT configurations, which are common in private and mobile energy systems, the neutral conductor (N) is grounded to increase safety. The connection between the neutral conductor and protective earth (N-PE) makes it possible to detect current flow in secondary circuits and interrupt the circuit in case of danger. In some systems, a shunt transformer can also generate its own neutral conductor. It has a grounding relay that is used for this purpose and can be controlled by an inverter/charger.

Protection against overtemperature

In the event of overheating, the autotransformer automatically disconnects from the power supply to prevent damage. A manual reset is required to restart the system.

Toroidal winding technology

A toroidal winding style consists of a coil wound around a ring-shaped core that has the shape of a torus or a donut. In a transformer, this means that the wire winding is wound in a closed loop around the torus-shaped core. This offers the following advantages:

• Low electromagnetic interference
• Efficient energy transfer
• Low-noise operation, compact design

Technical data

• Input and output voltage: 120/240 V
• Circuit breaker input: 100 A, two-pole
• Frequency: 50/60 Hz
• Max. switchable current at 240 V: 100 A
• Neutral current, 30 min: 32 A (3800VA)
• Neutral current, continuous at 40°C: 28 A
• Transformer type: Toroidal
• Housing: Aluminum
• Protection class: IP21
• Weight: 13.5 kg
• Dimensions: 425 x 214 x 110 mm

Scope of delivery

1x Victron autotransformer 120/240V-100A
Includes grounding relay