Beckwith Electric M‑0067E Tapchanger Control

The Beckwith Electric M‑0067E is a microprocessor‑based tapchanger control designed for automatic voltage regulation of power transformers equipped with load tap changers (LTCs). It continuously monitors the transformer output voltage and issues raise or lower commands to the tap changer motor drive to maintain the voltage within a programmed bandwidth. The M‑0067E is suitable for distribution, substation, and industrial transformers, offering precise voltage control, programmable settings, and robust construction for reliable long‑term operation.

Control and Operation

The M‑0067E features a voltage setpoint adjustable over a wide range, with independent bandwidth and time delay settings. It includes line drop compensation (LDC) to account for voltage drop along the feeder, ensuring that the voltage at the end of the line remains within acceptable limits. The control supports both single‑phase and three‑phase sensing, and includes a built‑in voltage reduction function for conservation voltage reduction (CVR) programs. A front‑panel keypad and LCD display allow easy local programming and monitoring.

The unit incorporates advanced algorithms to prevent excessive tap changer operations, extending the life of the LTC. It includes a block timer that limits the number of operations per hour, and a voltage‑dependent time delay that accelerates or decelerates response based on the magnitude of the voltage deviation. These features ensure stable voltage regulation while minimizing wear on mechanical components.

Key Features

Programmable voltage setpoint, bandwidth, and time delay. Line drop compensation with adjustable R and X settings. Voltage reduction mode for load shedding or conservation. Automatic and manual operation modes. Output contacts for raise, lower, and alarm functions. LED indicators for status and fault conditions. Communication via RS‑485 Modbus RTU for remote monitoring and control. The unit is housed in a rugged metal enclosure suitable for panel mounting.

Technical Specifications

Voltage input: 100‑480 VAC, 50/60 Hz, single‑phase or three‑phase. Accuracy: ±0.5% of reading. Output contacts: 2 Form C (raise/lower), rated 5 A at 250 VAC. Alarm contacts: 1 Form C, rated 5 A at 250 VAC. Power supply: 24‑250 VDC or 120‑240 VAC. Operating temperature: –30°C to +65°C. Enclosure: IP30, panel‑mount. Compliance with IEEE C57.15 and IEC 60255.

Applications

The M‑0067E is used on power transformers in utility distribution substations, industrial plants, and renewable energy installations. It is suitable for transformers with off‑circuit or on‑load tap changers, providing voltage regulation for feeders serving residential, commercial, and industrial loads.

Installation and Commissioning

Mount the control in a panel cutout. Connect voltage sensing leads from the transformer secondary, control power, and motor drive outputs. Commissioning involves setting the voltage setpoint, bandwidth, time delay, and LDC parameters. The unit includes a simulation mode for functional testing without operating the tap changer.

Reliability and Quality

Beckwith Electric’s M‑0067E is built with industrial‑grade components and conformal‑coated circuit boards. It undergoes rigorous testing for temperature, humidity, and surge immunity. The control has a proven MTBF exceeding 100,000 hours.

Conclusion

The Beckwith Electric M‑0067E tapchanger control offers precise, reliable, and programmable voltage regulation for transformer load tap changers. Its advanced features and robust construction make it an ideal solution for maintaining voltage quality in distribution and substation applications.