ETE MV400P3S3 Multi-Voltage Control Transformer 400VA 0/120V + 0/120V to 0/12V + 0/12V

Why Choose the ETE MV400P3S3 Multi-Voltage Control Transformer?

The ETE MV400P3S3 is a versatile 400 VA single-phase multi-voltage control transformer designed to provide reliable electrical isolation and flexible low-voltage AC power for industrial machinery, electrical control panels and automation systems. Part of the ETE MV Multi-Voltage transformer series, it features dual 120 V AC primary windings and dual 12 V AC secondary windings, allowing different input and output voltage configurations.

Manufactured by Eastern Transformers & Equipment (ETE), the MV400P3S3 supports 120 V AC input using parallel-connected primary windings or 240 V AC input using series-connected primary windings. Its secondary windings can be connected in parallel to provide 12 V AC or in series to provide 24 V AC, making it suitable for industrial installations requiring adaptable control voltages.

With a rated capacity of 400 VA, Class E insulation and 8% voltage regulation, this transformer provides a practical solution for electrical control systems requiring selectable primary and secondary connections. Measuring 120 × 108 × 120 mm and weighing 5.5 kg, the MV400P3S3 is suitable for integration into industrial electrical equipment, with EPH 3 or EPN 2 specified as enclosure references.

Key Advantages

• 400 VA rated capacity supports a range of industrial control circuit applications.
• Dual 120 V AC primary windings provide flexible input voltage configuration.
• 120 V AC parallel primary connection accommodates compatible 120 V AC supplies.
• 240 V AC series primary connection accommodates compatible 240 V AC supplies.
• Dual 12 V AC secondary windings provide flexible low-voltage output connections.
• 12 V AC parallel secondary connection allows the windings to share the connected load.
• 24 V AC series secondary connection provides a higher nominal output voltage.
• Electrical isolation between the primary supply and secondary control circuits.
• 8% voltage regulation provides a defined measure of secondary voltage variation under load.
• Class E insulation supports dependable industrial transformer operation.
• EPH 3 or EPN 2 enclosure references assist with protective enclosure selection.

Key Features

• ETE MV Multi-Voltage transformer series.
• 400 VA rated apparent power.
• Single-phase transformer configuration.
• Primary terminals: 0/120 V + 0/120 V.
• Dual primary windings configurable for 120 V AC parallel or 240 V AC series input.
• Secondary terminals: 0/12 V + 0/12 V.
• Dual secondary windings configurable for 12 V AC parallel or 24 V AC series output.
• Flexible primary and secondary winding arrangements for compatible control systems.
• 8% voltage regulation.
• Class E insulation system.
• EPH 3 or EPN 2 enclosure reference.
• 120 × 108 × 120 mm overall dimensions.
• 5.5 kg transformer weight.

Flexible 120 V AC or 240 V AC Primary Connections

The ETE MV400P3S3 features two separate primary windings, each with terminals marked 0/120 V. This dual-primary arrangement allows the transformer to operate from either a nominal 120 V AC or 240 V AC supply when the windings are connected correctly.

• 120 V AC input: The two primary windings are connected in parallel with matching polarity so that each winding receives the nominal 120 V AC supply.
• 240 V AC input: The two primary windings are connected in series with the correct polarity so that the nominal 240 V AC supply is applied across the combined windings.

This flexibility makes the MV400P3S3 particularly useful for OEM machinery manufacturers, electrical panel builders and industrial control system integrators working with equipment intended for different supply voltages.

The transformer does not automatically detect or switch between supply voltages. The primary windings must be configured correctly before energising the unit, following ETE's connection instructions and applicable electrical safety requirements.

Selectable 12 V AC or 24 V AC Secondary Output

The MV400P3S3 incorporates two separate secondary windings, each with terminals marked 0/12 V. These windings can be configured to provide either a nominal 12 V AC or 24 V AC output for compatible control equipment.

• 12 V AC parallel output: The two secondary windings are connected in parallel using matching polarity, maintaining a nominal 12 V AC output while allowing the windings to share the connected load.
• 24 V AC series output: The two secondary windings are connected in series with the correct polarity to provide a nominal combined output of 24 V AC.

The 400 VA rating applies to the complete transformer and must not be interpreted as 400 VA available independently from each secondary winding. Parallel connections require correct winding polarity and appropriate current sharing, while series connections must be arranged to produce the intended combined voltage.

All primary and secondary winding connections should follow ETE's wiring instructions, including suitable circuit protection, conductor selection and load assessment. Incorrect series or parallel connections may cause excessive current, incorrect output voltage or damage to connected equipment.

Reliable Control Power with 8% Voltage Regulation

The ETE MV400P3S3 has a specified 8% voltage regulation, describing the change in secondary voltage between the manufacturer's defined loading conditions. This provides useful information when selecting the transformer for control circuits where the connected load may vary during operation.

Combined with its Class E insulation system, 400 VA capacity and configurable primary and secondary windings, the transformer offers a practical solution for industrial applications requiring adaptable low-voltage AC control power.

Typical Applications

• Industrial electrical control panels requiring isolated 12 V AC or 24 V AC supplies.
• Machinery operating from nominal 120 V AC or 240 V AC supplies.
• Industrial automation and machine control equipment.
• 12 V AC and 24 V AC relay and contactor control circuits.
• Low-voltage industrial signalling and indication equipment.
• OEM machinery manufactured for different electrical supply voltages.
• Building services and HVAC control systems.
• Manufacturing plant and production line control equipment.
• Electrical panel building and control system integration.