ST620

Product Description

The ST620 is designed for shaft speed 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 shaft rotational speed, 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 50000 rpm

• 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