Industrial Control Transformers

An industrial control transformer provides a stable, low-voltage power source for control circuits used in machinery and electrical equipment. It isolates control wiring from the main power circuit and helps maintain consistent voltage during momentary inrush conditions caused by contactors, relays, or solenoids. These transformers ensure control reliability, reducing voltage dips that could cause nuisance tripping or component failure. They are commonly installed in motor starters, conveyors, HVAC systems, and automated industrial equipment where dependable control voltage is critical for safe and efficient operation.

An industrial control transformer is designed to handle high inrush currents and intermittent loads, whereas a power transformer is optimized for continuous operation at full load. The control transformer’s lower impedance and enhanced voltage regulation characteristics allow it to maintain stable secondary voltage even under sudden inrush demands. Its magnetic core is optimized for high flux density, enabling quick recovery and reduced voltage drop during contactor energization. This makes it ideal for control circuits and pilot devices that must function reliably even under fluctuating load conditions, which a standard power transformer may not accommodate effectively.

To size an industrial control transformer, calculate the total steady-state VA of all connected control devices, such as coils, timers, and indicator lights, that will operate simultaneously. Next, multiply that value by an inrush factor (typically between 3× and 10×, depending on coil type) to account for momentary demand. Select a transformer whose continuous VA rating meets or exceeds this calculated requirement. Rex Power Magnetics provides comprehensive sizing charts and engineering support to help customers select the appropriate model for their system voltage, frequency, and environmental conditions. Proper sizing ensures voltage stability, prevents overheating, and extends equipment life.

Rex Power Magnetics industrial control transformers are typically supplied with dual primary and dual secondary windings—for example, 240×480 V primary and 120×240 V secondary—allowing flexibility in connection for various voltage requirements. These windings can be connected in series or parallel to accommodate single- or three-phase systems. Custom voltage ratings, frequencies (50/60 Hz), and tap configurations are available upon request to meet global application standards. The design versatility makes it easy for OEMs and system integrators to use the same model in different control panels or machinery configurations, simplifying inventory and reducing installation time.

All Rex Power Magnetics industrial control transformers are CSA certified and UL recognized. They comply with CSA C22.2 No. 66 and UL 5085-2 standards, ensuring adherence to industry requirements for safety, insulation, and performance. Each unit is manufactured under an ISO 9001-certified quality management system that guarantees traceability and process control. The designs meet or exceed temperature rise specifications, while dielectric testing ensures long-term reliability in demanding environments. Rex’s adherence to international standards demonstrates its commitment to consistent quality, durability, and dependable performance across all control transformer applications.

Industrial control transformers experience short, high inrush current when loads such as contactors or solenoids are energized. Rex Power Magnetics designs its transformers with optimized magnetic core materials, low-impedance windings, and high thermal capacity to handle these transient demands. This ensures the secondary voltage remains stable, even during peak current events. The transformer’s design includes superior voltage regulation characteristics and minimal magnetic losses, allowing it to quickly recover to steady-state voltage after an inrush event. This performance minimizes voltage dips that could otherwise cause control circuit malfunctions, ensuring smooth and reliable equipment operation.

Rex Power Magnetics offers industrial control transformers in several configurations to suit diverse installation requirements. Open core-and-coil units are ideal for integration within OEM control panels, while enclosed models are available in NEMA 1, 3R, 4, and 12 rated housings for additional protection. Enclosures can be wall-mounted, floor-mounted, or panel-mounted, providing flexibility for indoor or outdoor installations. Each design supports easy access for wiring and inspection while maintaining safety and ventilation standards. The wide range of mounting and enclosure options ensures compatibility with both standard and custom control system layouts.

Yes. When properly installed in rated enclosures or used in conjunction with Rex Power Magnetics’ hazardous-location designs, industrial control transformers can safely operate in demanding environments. These include areas exposed to moisture, dust, corrosive agents, or explosive vapors. Suitable NEMA-rated or explosion-proof housings ensure compliance with environmental protection standards. Additionally, transformers can be designed with epoxy or varnish encapsulation to improve moisture resistance. Proper grounding, ventilation, and insulation practices are essential for maintaining performance and safety in such locations, and Rex provides guidance to ensure compliance with applicable codes and regulations.

Industrial control transformers are generally low-maintenance devices, but periodic inspection is recommended for optimal performance. Maintenance involves verifying that terminals are tight, checking insulation for discoloration or cracks, and ensuring adequate ventilation around the unit. Any accumulated dust or debris should be removed to prevent overheating. If the transformer operates in high-humidity or corrosive environments, visual inspections should occur more frequently. Under normal operating conditions, Rex Power Magnetics industrial control transformers provide years of reliable service with minimal attention, thanks to robust construction and high-quality insulation materials.

Yes. Rex Power Magnetics specializes in custom industrial control transformer solutions tailored to unique applications. Options include non-standard voltage ratios, frequency adaptations, fusing, terminal configurations, special nameplates, and mechanical mounting variations. Engineering support is available to assist OEMs and system designers with technical requirements such as space constraints, harmonic considerations, or environmental protection. Each custom unit undergoes the same rigorous testing and quality assurance as standard models, ensuring performance consistency and compliance with applicable standards. This flexibility allows Rex to meet specialized industrial and international market needs effectively.