Three-phase system insulation monitor ISOMETER® iso685 series

for AC networksAC/DCDC

Overview
The ISOMETER® iso685 is an insulation monitoring device according to IEC 61557-8 for IT systems. It is suitable for AC, 3(N)AC, AC/DC and DC systems, including AC systems with directly connected DC components (rectifiers, inverters, variable-speed drives).

Key benefits

• Predefined measurement profiles for common application scenarios
• Reliable measurement of insulation resistance, system voltage, capacitance and frequency
• Integrated web server and support for Modbus TCP/RTU
• History memory with real-time clock (buffer ~3 days, up to 1023 alarm messages)
• Automatic adaptation to system leakage capacitance

Device variants

• iso685-D: Variant with high-resolution graphic LC display and local operating elements; direct operation of device functions; not combinable with FP200.
• iso685-S: Variant without display or local controls; intended for operation with FP200 front panel only.
• Option "W": Versions with option W for extreme climatic and mechanical conditions (iso685W-D and iso685W-S).

Features

• Operation in IT AC systems with galvanically connected rectifiers/inverters and in IT DC systems
• Automatic adaptation to existing system leakage capacitance
• Combination of AMPPlus with other profile‑specific measurement methods
• Two separately adjustable response value ranges: 1 kΩ…10 MΩ
• Connection monitoring of measuring lines and automatic device self test
• Graphical isoGraph showing insulation resistance over time
• Analogue outputs: 0(4)…20 mA, 0…400 μA, 0…10 V, 2…10 V (galvanically separated)
• Freely programmable digital inputs and outputs
• Remote configuration via webserver (option: COMTRAXX® Gateway) and service remote diagnosis
• Interfaces: RS-485/BS (Bender sensor bus), BCOM, Modbus TCP/RTU
• Voltage measurement expandable via coupling devices

Applications

• Main circuits in AC, DC or AC/DC installations
• AC/DC circuits with directly connected DC components (rectifiers, converters, drives)
• UPS and battery systems
• Phase‑controlled heaters and systems with switched‑mode power supplies
• IT systems with high leakage capacitances

Variant table (Type | Nominal system voltage range Un | Supply voltage US | Display | Option W | Art. No.)
iso685-D | AC 0…690 V; 1…460 Hz / DC 0…1000 V | AC 24…240 V; 50…400 Hz / DC 24…240 V | integrated | – | B91067010
iso685W-D | AC 0…690 V; 1…460 Hz / DC 0…1000 V | AC 24…240 V; 50…400 Hz / DC 24…240 V | integrated | -40…+70°C, 3K23, 3M12 | B91067010W
iso685-S + FP200 | AC 0…690 V; 1…460 Hz / DC 0…1000 V | AC 24…240 V; 50…400 Hz / DC 24…240 V | detached | – | B91067210
iso685W-S + FP200 | AC 0…690 V; 1…460 Hz / DC 0…1000 V | AC 24…240 V; 50…400 Hz / DC 24…240 V | detached | -40…+70°C, 3K23, 3M12 | B91067210W

Optional accessories

• Coupling devices: AGH150W-4, AGH204S-4, AGH520S, AGH676S-4
• Terminal sets and enclosure accessories (some items included in delivery)

Technical specifications

• Standard: IEC 61557-8 (insulation monitoring for IT systems)
• Applicable systems: AC, 3(N)AC, AC/DC and DC
• Measurement functions: insulation resistance, voltage, capacitance, frequency
• Response value ranges: 1 kΩ … 10 MΩ (two separately adjustable ranges)
• Analogue outputs: 0(4)…20 mA, 0…400 μA, 0…10 V, 2…10 V (galvanically separated)
• Interfaces: RS-485/BS, BCOM, Modbus TCP/RTU, integrated web server
• History memory: up to 1023 alarm messages with timestamp (buffer ~3 days)
• Environmental option W: -40…+70°C (protection classes e.g. 3K23, 3M12)