Description

Part-turn Intelligent Electric Actuator Overview

The part-turn intelligent electric actuator from Bonray – specifically the BJ/BJM20-IIC series – represents a major advancement in process control actuation. This non-intrusive, smart actuator integrates high-precision absolute encoding position and torque sensors, a patented planetary gear transmission, and a full-color English dot-matrix LCD interface. Designed for quarter-turn valves such as butterfly valves, ball valves, plug valves, and dampers, this actuator delivers output torque from 50 N·m to 3,000 N·m and angular travel from 0° to 90° (or other angles upon request). Bonray engineers focused on eliminating common failure points found in traditional worm-gear actuators – such as manual/electric switching faults – by removing the mechanical clutch altogether. The result is a robust, high-efficiency actuator suitable for power plants, oil refineries, chemical complexes, marine systems, food processing, paper mills, building automation, municipal water treatment, and environmental protection projects.

You can order this part-turn intelligent electric actuator with multiple fieldbus options (Profibus‑DP, Modbus, DeviceNet, FF, Hart), ESD override, analog (4‑20 mA) control, and two-wire control. For extreme conditions – high temperature or strong vibration – Bonray offers a split‑version (BJ/BJM-IICF) that relocates the control electronics to a remote enclosure connected by a standard 10‑meter cable (longer upon request). The actuator housing meets IP68 submersion protection (2 meters for 48 hours) and, with optional flameproof certification, serves safely in gas explosion zones 1/2 (Ex db IIC T4 Gb) and dust explosion zones 21/22 (Ex tb IIIC T130°C Db).

Part-turn Intelligent Electric Actuator Features

Bonray built the BJ/BJM20-IIC series with user-centric innovations. Below we detail each feature in active voice to help you understand exactly how this actuator improves your operations.

1. Full English Menu on High‑Resolution Dot‑Matrix LCD

The actuator shows valve position as large digits and displays alarm messages, working status, and configuration menus in clear language (Chinese or English). High‑brightness LEDs indicate open limit, closed limit, and intermediate positions. You can read the display even in poor lighting conditions.

2. Non‑Intrusive Design – No Cover Opening for Commissioning

You set all parameters and query system status using the magnetic operating knob or the optional infrared setting tool. Hall sensors inside the sealed housing detect knob rotation without any physical opening. This keeps dust, moisture, and corrosive gases away from the electronics, drastically improving reliability in dirty or humid environments.

3. Simultaneous Manual and Electric Operation

Unlike traditional actuators, this unit has no manual/electric changeover mechanism. You can operate the handwheel at any time, even while the motor runs. This completely eliminates the most common failure point in worm‑gear actuators – stuck or damaged clutches.

4. Absolute Encoding Position Sensor (Patented BM12)

The BM12 single‑turn absolute encoder uses non‑contact measurement. It does not require battery backup to retain valve position after a power loss. The valve position always remains correct, and the sensor provides extremely high reliability and long life.

5. Absolute Encoding Torque Sensor (Patented)

Bonray’s innovative absolute encoding torque sensor directly measures output torque using non‑contact technology. It resists ambient temperature changes and voltage fluctuations. You can set a torque protection value (30% to 100% of rated torque) via the menu, and the actuator continuously displays real torque. This protects both valve and actuator from overload damage.

6. Split‑Version for Harsh Conditions (BJ/BJM-IICF)

When you face high ambient temperatures or strong vibrations, choose the split version. The control electronics reside in a separate controller enclosure, and a standard 10‑meter cable (extendable upon order) connects it to the actuator body. You achieve all the same smart functions without exposing sensitive electronics to the harsh environment.

7. Double Sealed Enclosure – IP68 and Flameproof Options

The housing uses O‑rings for static joints and oil seals for dynamic joints, achieving IP68 rating (submersion at 2 meters for 48 hours per GB4208‑2017). The terminal box features double sealing: even when you remove the terminal cover for field wiring, the inner seal protects internal components. For hazardous areas, Bonray provides gas‑explosion proof (Ex db IIC T4 Gb) and dust‑explosion proof (Ex tb IIIC T130°C Db) enclosures.

8. Multiple Control Modes

• Local control: When you turn the selector knob to “Local”, you operate the valve using the magnetic knob or infrared setter in either “jog” or “hold” mode.

• Remote switch control (remote manual): With the knob at “Remote”, three digital inputs (open, close, stop/hold) accept dry contacts or voltage signals (24V DC or 220V AC). You select “jog” or “hold” behavior.

• Remote analog control (remote auto): The actuator accepts 4‑20 mA (or optional 0‑20 mA, 0‑10V, etc.) for precise positioning.

• ESD control: An emergency signal overrides any local or remote command. You configure ESD as active‑high or active‑low, and you decide whether it overrides motor overheating, the selector knob in stop position, or intermittent operation.

• Fieldbus control: Add Profibus‑DP, Modbus, DeviceNet, FF, or Hart for digital closed‑loop control.

• Two‑wire control: Choose “signal open / no‑signal close” or “signal close / no‑signal open” for special applications.

• Intermittent operation: The actuator moves in a pulsed “stop‑and‑go” manner to extend travel time, preventing hydraulic shock or fluid surging.

9. Comprehensive Protection Functions

• Position limit protection: Automatically stops at open and close limits.

• Torque overload protection: Prevents damage to valve and actuator.

• Automatic phase sequence correction: The actuator detects incoming three‑phase power phase order and internally corrects it – you never worry about swapping phases.

• Instantaneous reversal protection: Adds a time delay when you command a reverse direction, saving valve stem and gearbox from unnecessary wear.

• Phase loss protection: Detects missing phase and disables the motor to prevent overheating.

• Valve stuck protection: When the motor starts, the actuator temporarily disables torque protection for 0.2‑0.3 seconds (0.2‑0.3 s for normal direction, 5‑8 seconds when opening from fully closed) to break free a stuck valve.

• Motor overheat protection: A thermal relay embedded in the motor winding cuts off control power if the winding overheats.

• Galvanic isolation: All I/O channels use opto‑couplers for noise immunity.

10. Non‑Volatile Status Indication

You can configure the four bistable (magnetic latching) output contacts to indicate various valve states – open limit, close limit, torque trip, running, or any intermediate position. These contacts retain their state even during a power outage.

11. Self‑Locking Capability

The planetary gear train provides reverse self‑locking. The actuator will not back‑drive when you remove power or lose the control signal.

12. Emergency Handwheel

The handwheel allows you to operate the valve manually during a power failure.

Model and Type

Bonray’s part-turn intelligent electric actuator family divides into three operational types based on duty cycle and control precision.

1. BJ20-IIC On‑Off Type (Switch Type) Part-turn Intelligent Electric Actuator

• No proportional control function.

• Suitable for applications with ≤60 starts per hour, ≤10 minutes continuous running, and duty cycle ≤33.3%.

• Ideal for simple open/close service where positioning accuracy is not critical.

2. BJ20-IIC Intermittent Modulating Type Part-turn Intelligent Electric Actuator

• Includes proportional control (4‑20 mA analog or fieldbus).

• Up to 60 starts per hour (three‑phase models can reach 600 starts per hour for short periods), ≤10 minutes continuous, duty cycle ≤33.3%.

• Good for modulating duty such as pressure or flow regulation with moderate cycling.

3. BJM20-IIC Frequent Modulating Type Part-turn Intelligent Electric Actuator

• Uses a special motor rated for high cycling and solid‑state relays (no mechanical contacts) in the drive unit.

• Faster control chip and optimized algorithms achieve 1200 starts per hour (three‑phase) or 600 per hour (single‑phase), with duty cycle up to 50%.

• Higher positioning accuracy than the BJ types.

• Designed for demanding closed‑loop automatic control applications requiring frequent small movements.

Available Torque / Speed Combinations

Specifications

Can I install the part-turn intelligent electric actuator without opening the electrical cover?

Yes. Bonray designed the BJ/BJM20-IIC series with non‑intrusive magnetic knobs and an optional infrared setter. You perform all configuration, calibration, and diagnostics without removing the cover. This preserves the IP68 seal and prevents ingress of dust or moisture.