Description

Multi-turn Explosion-proof Actuator BD180-C8 Overview

The BD180-C8 multi-turn explosion-proof actuator from Bonray represents a convergence of advanced sensing, robust mechanics, and intelligent control. To appreciate its capabilities, one must look beyond its external housing and understand the technologies inside. This overview delves into the core innovations that make this actuator a superior choice for process control professionals. At our Bonray R&D center, we focused on solving real-world problems—loss of position after power failure, complex setup procedures, environmental ingress, and the need for reliable data. The result is a multi-turn electric actuator that not only moves valves but also provides a wealth of information and operates with unprecedented reliability.

How does the absolute encoder work without a battery?

The patented BM18 multi-turn absolute encoder is a non-contact sensor that uses a unique mechanical gear train and magnetic sensing principle. It physically tracks the position of the output shaft across multiple rotations. Because it’s absolute, it does not need to count pulses from a reference point. This means it remembers the exact position, even after a power loss, without the need for a battery. This Suzhou Bonray innovation eliminates a common point of failure found in other multi-turn electric actuator designs.

Multi-turn Explosion-proof Actuator BD180-C8 Features

The BD180-C8 series multi-turn explosion-proof actuator features several key technologies. The BM18 absolute encoder is the centerpiece, providing reliable position data without the maintenance of batteries. The continuous torque measurement system uses strain gauge technology to provide real-time torque feedback. This data appears on the LCD and can be transmitted via the 4-20mA output. This allows for advanced diagnostics, such as detecting valve seat wear or process changes.

The power electronics include an auto-phase correction system that uses a sophisticated algorithm to detect the incoming phase sequence. This ensures the motor always runs in the correct direction, regardless of how the electrician wired the supply. The control board uses opto-isolation on all input/output channels, providing electrical separation between the actuator’s internal logic and external control systems. This noise immunity is critical for reliable operation in industrial environments, a key consideration in Suzhou Bonray’s design.

Protect Functions

The protective functions in this multi-turn electric actuator are not standalone; they work in concert. The torque measurement system feeds data to the control board, which uses it to implement the torque overload and valve seizure protection functions. The auto-phase correction system works with the phase loss detection to ensure the motor only receives clean, correct power. The motor thermal protection (thermostat) is a direct, analog sensor embedded in the windings, providing the most accurate temperature data to the control logic.

These systems integrate into a unified protection scheme. For instance, if the motor is overheating, the system disables operation. If a phase is lost, the system prevents start-up. This integrated approach, a hallmark of Bonray’s engineering, ensures that the multi-turn electric actuator protects itself and the valve from a wide array of potential faults.

Control 

The BD180-C8 supports a wide range of control methods through its flexible hardware and software architecture. Remote switch control inputs are processed by the main control board, which can be configured for level or pulse commands. The analog input is a high-resolution 4-20mA signal that the control board samples at a high rate, using a PID-like algorithm to position the valve with high accuracy. For ESD, a separate, prioritized input bypasses the normal command logic to enforce the safe position.

For fieldbus, the optional card physically plugs into the main board, adding a dedicated communication processor. This processor handles the network protocol, offloading the main processor to focus on motor control and protection. This modular design ensures that the base actuator’s performance remains uncompromised, regardless of the network you connect it to. Suzhou Bonray’s expertise in industrial communication ensures seamless integration.

Model and Type

The technical difference between the BD-C8 and BDM-C8 series lies primarily in the motor control unit. The BD-C8 models use standard, robust contactors for motor switching. They are well-suited for their rated duty cycle. The BDM-C8 Frequent Modulating models use solid-state relays (SSRs) to switch the motor. SSRs have no moving parts, can switch at a much higher frequency, and produce less electrical noise. This, combined with a motor designed for frequent starts and a higher-capacity control processor, gives the BDM-C8 its 1200 starts/hour capability and superior positioning precision.

The split-body (C8F) model is technically identical in function to its integrated counterpart. The only difference is the physical separation. A long, shielded cable carries all control and feedback signals between the actuator body and the remote control unit. This allows the electronics to operate within its ideal temperature range while the motor and gear train handle the harsh conditions on the valve.

Specifications

• Power Supply: 380VAC ±10%, 50Hz ±2% (3-phase), or 220VAC ±10%, 50Hz ±2% (1-phase). Other voltages/frequencies (110V, 115V, 208V, 230V, 400V, 415V, 440V at 50/60Hz) are available.
• Control Input: 4-20mA analog, dry contacts, 24VDC, 220VAC pulse/level signals, and fieldbus protocols.
• Feedback Output: 4-20mA analog, 4 configurable bi-stable output contacts, 1 remote indication contact, 1 fault alarm contact.
• Output Torque: 50 N.m to 3500 N.m (up to 300,000 N.m with gearboxes).
• Output Speed: 12 rpm to 144 rpm
• Ambient Temperature: -30°C to +70°C.
• Protection Class: IP68, optional Ex db IIC T4 Gb, Ex tb IIIC T130℃ Db.
• Mounting: Complies with ISO 5210:2017 (GB/T12222-2023) and JB2920-81.