The isoUG425-D4-4 is an insulation monitoring device designed for unearthed DC systems (IT systems). It uses a passive measurement method (without injecting a measuring voltage) to continuously monitor the asymmetrical insulation resistance R_F of DC main circuits.
This device is particularly suitable for simple battery systems, DC control voltage systems, and DC lighting circuits. The passive measurement technique detects only asymmetrical insulation faults (where the insulation of one pole deteriorates). Symmetrical faults (where the insulation resistance of both poles to earth decreases equally) are not detected.
In addition, the device features undervoltage and overvoltage detection, providing comprehensive diagnostic information on system voltage status.
Technical Specifications
· Rated system voltage (Uₙ): DC 12…120 V
· Maximum permissible system leakage capacitance (Cₑ): ≤ 50 μF
· Supply voltage (Uₛ): AC 100…240 V, 47…63 Hz / DC 24…240 V
· Insulation resistance response values (Rₐₙ₁ / Rₐₙ₂): Two independently adjustable thresholds, range 1…100 kΩ
· Voltage monitoring: System voltage (r.m.s. and DC) with undervoltage/overvoltage detection
· Alarm outputs: Two independent changeover contacts (K1, K2) with 2 N/O contacts each; contact rating AC 250 V / 5 A (AC‑12)
· Display: Multi‑function LC display with backlight, showing measured values, alarm status and device parameters
· Communication interface: Electrically isolated RS‑485 supporting Modbus RTU and BMS (Bender Measuring Device Interface) protocols
· Alarm indication: Front‑panel LEDs (AL1, AL2), display and alarm relays
· Fault memory: Selectable latching function for alarm signals
· Password protection: Prevents unauthorised parameter changes
· Protection class: Internal components IP30, terminals IP20
· Connection type: Push‑wire terminals
· Mounting: DIN rail (35 mm), width 45 mm
· Weight: approx. 150 g
· Order number: B71036320
Key Features
· Passive measurement method – Detects asymmetrical insulation faults by measuring displacement voltage; no measuring voltage is injected. Note that symmetrical faults (equal degradation of both poles) are not detected.
· Wide measuring range and self‑adaptation – Response values adjustable from 1 kΩ to 100 kΩ; automatically adapts to system leakage capacitance up to 50 μF.
· Multi‑parameter monitoring – Measures insulation resistance, system voltage (true RMS and DC), undervoltage/overvoltage, and DC residual voltage to earth.
· Flexible alarm configuration – Two alarm relays (K1/K2) configurable as N/O or N/C; selectable fault memory.
· User‑friendly operation – Backlit LC display for reading measured values and adjusting parameters; supports external test/reset push‑buttons.
· Integrated communication – Isolated RS‑485 port with Modbus RTU and BMS protocols for integration with PLC or SCADA systems.
· Easy wiring – Push‑wire terminals for solid and ferrule‑terminated conductors.
Typical Applications
· Simple battery systems – continuous insulation monitoring of unearthed DC IT systems
· DC control voltage systems – insulation monitoring in industrial control circuits and automation systems
· DC lighting circuits – monitoring for earth fault prevention
· Power plants and substations – early warning for insulation faults in DC control circuits
· Railway and transport systems – insulation monitoring of DC control circuits
Translation missing: en.general.search.loading