ST520

Product Description

The ST520 is designed for radial shaft vibration monitoring in rotating machinery. The vibration protection module works with an eddy current probe, 

extension cable and proximity driver to form a complete vibration monitoring system. The module supplies power to the proximity driver and receives its 

feedback signals, which are processed to provide redundant 4–20mA standard outputs proportional to vibration amplitude, directly connectable to PLC, 

DCS or SCADA systems.

The module features a standalone design for easy deployment, making it ideal for distributed point monitoring with a simple and cost-effective system 

architecture. The instrument is equipped with a BNC buffered output for raw vibration signal access, ideal for on-site verification, waveform analysis and fault 

diagnosis. It maintains high accuracy and stable output characteristics even in harsh industrial environments, supporting equipment predictive maintenance 

and fault warning to meet high-reliability monitoring requirements.

Key Specifications

Electrical Specifications

• Supply Voltage: 20 VDC to 30 VDC (Nominal 24 VDC); 190 to 250 VAC

• Frequency Response (±3 dB):

• Standard Version: 2.0 to 4200 Hz

• Low Frequency Version: 0.5 to 120 Hz

• Full Scale Range: 0 to 200 μm pk-pk

• Buffered Output: Unfiltered raw signal, Output Impedance: 150 Ω

• 4-20 mA Output: Active output, Max Load Impedance: 385 Ω

• Alarm Relay Specifications:

• Sealing: Epoxy resin sealed

• Contact Type: SPDT

• Isolation Voltage: 1000 VDC

• Alarm Settings:

• Adjustable Range: Full scale

• Delay Time: 1 to 60 s adjustable

• Factory Default: 3 s delay

Physical Specifications                                                                                                                                                                   

• Dimensions (L×W×H):

• 122 × 53.4 × 90 mm (DIN Rail Mount)

• 122 × 68.4 × 90 mm (Panel Mount)

• Weight: 496 g

• Housing Material: Aluminum alloy

  
  

Environmental Specifications:

• Operating Temperature: -40 °C to +80 °C

• Storage Temperature: -40 °C to +100 °C

• Operating Humidity: 5% to 95% RH, non-condensing

  
  

Hazardous Area Approvals:

•  ATEX: 

             II 1G, Ex ia IIC T4 Ga

             II 2D, Ex ib IIIC T130 °C Db

                 （-40 °C to +80 °C）

• CNEx:       

        Ex ia IIC T6 Ga

        Ex ib IIIC T80 °C Db

• CSA/NRTL/C:

              Class I Division 2, Groups A, B, C, D

              T5 @ Ta = 85 °C, Type 4