Description
BENDER W4-S140
Technical Specifications: Rated monitoring voltage range: Up to 140V AC/DC Measurement method: Pulse injection measuring principle Display: Local digital display for insulation resistance value Communication: Modbus RTU Relay output: Two relay contacts for pre-alarm and main alarm Operating temperature: -20℃ to +60℃ Storage temperature: -40℃ to +85℃ Relative humidity: 10% to 95%, non-condensing Protection class: IP40 for housing Mounting: DIN rail mounting Alarm threshold: Adjustable insulation resistance setting
Functional Features: Continuous insulation resistance measurement for unearthed IT power systems. Two-stage alarm function including pre-warning and fault alarm. Local digital readout of real-time insulation resistance value. Modbus RTU communication to transmit measurement data and alarm status to PLC or SCADA. Adjustable alarm threshold according to system requirements. Built-in self-test function to verify device health status. Relay contact output for external alarm lamp or audible alarm device. Immunity to system capacitance interference in long cable networks.
Application Scenarios: Medical isolated power supply system, marine IT power network, industrial uninterrupted power system, mining auxiliary power distribution, data center isolated auxiliary power, mobile vehicle mounted isolated power system.
Performance Parameters: Insulation resistance measuring range covers low to high resistance values. High measurement stability under capacitive load from long power cables. Fast fault detection response for insulation drop. Long-term continuous monitoring without interrupting power supply.
Material Composition: Flame retardant plastic DIN rail housing. FR4 printed circuit board with measuring circuit. Microprocessor and high precision sampling components. Relay switching components for alarm output. Screw terminals for power supply and signal wiring.
Structural Features: Compact DIN rail mount enclosure. Front panel with digital display, status LEDs and setting buttons. Screw terminal blocks located at bottom side for wiring connection. Internal isolation between measuring circuit and power supply circuit. Small footprint for installation inside low voltage distribution cabinet.
Working Principle: The device injects defined measuring pulse signal into unearthed IT power network. The measuring circuit samples return signal and calculates insulation resistance between live conductor and earth. When insulation resistance drops below pre-set pre-alarm threshold, pre-warning relay activates. When value falls below main alarm threshold, fault relay triggers. Measurement data and alarm status are transmitted via Modbus RTU bus to upper monitoring system. Built-in self-test circuit checks measuring hardware periodically.
Installation Requirements: Mount device on standard DIN rail inside low voltage cabinet. Connect power supply terminals according to nameplate specification. Run measuring wiring directly to unearthed power conductors. Use shielded cable for Modbus RTU communication wiring. Complete protective earth connection for device housing. Keep device away from high frequency interference equipment.
Usage Notes: Adjust alarm threshold matching the actual IT network cable length and load characteristics. Execute self-test function after installation or maintenance. Do not connect to earthed TN or TT power distribution systems. Cut off power supply before modifying measuring wiring. Check relay contact rating before connecting external alarm load. Perform periodic calibration according to BENDER operation manual.
