ISOMETER® iso1685FR / iso1685FRM

ISOMETER® iso1685FR / iso1685FRM

The ISOMETER® iso1685FR… is an insulation monitoring device for IT systems in accordance with IEC 61557-8. It is applicable for use in AC systems.

Particularities of the ISOMETER® iso1685FRM
The only difference between the ISOMETER® iso1685FRM and the ISOMETER® iso1685FR is the following: By means of the Modbus-analogue converter M-7024, the ISOMETER® iso1685FRM provides an analogue output. Communication takes place via Modbus RTU. The DIP switch can be used to switch between the BMS and Modbus protocol.

Insulation monitoring is carried out using an active measuring signal which is superimposed via the integrated coupling of the IT system to earth.
If the impedance value Ze between the IT system and earth falls below the set response value Zan, the alarm LEDs ALARM 1 and ALARM 2 light up, and the alarm relays K1 and K2 are
switched on. In addition to the active method, an optional passive method can be activated which monitors the unbalance of the IT system by measuring the voltage between the star
point and earth of the IT system. If the voltage UN-PE between the star point and earth exceeds the set response value Uan, the alarm LEDs ALARM 1 and ALARM 2 light up and the alarm relays K1 and K2 switch.
Both measuring methods (active and passive) work in parallel to the alarm relays K1 and K2.
The integrated μSD card is used as data logger for storing all relevant events.
The following measured values, statuses and alarms are stored during operation:
• Impedance Ze between the system and earth
• Insulation fault Re between the system and earth (when the system capacity has been set)
• Voltage between the star point and earth
• System frequency
• Insulation fault
• Connection fault
• Device error


  • Kenmerken
  • Toepassingen
  • Accessoires
  • Bestelgegevens
  • Downloads
  • monitoring of AC and 3NAC systems with low leakage capacitance (< 200 nF)
  • Fast tripping due to the patented SSCP (Synchron Sine Correlation Principle) measurement method: Notification of an insulation fault or shutdown within 150 ms
  • Impedance measurement between the system and earth (detection of ohmic and capacitive insulation faults)
  • Response value Zan: 10…1000 kΩ
  • Configurable interference detection for the active method (interference level, consecutive number of disrupted measurement periods) with the possibility of triggering a device error in the event of continuous interference
  • Measurement of the star point shift to earth (UN-PE)
  • Visual signalling of alarms, or connection or device errors via LEDs
  • 2 redundant alarm relays for the notification of insulation faults
  • Connection monitoring of L1/+, L2/–
  • Monitoring of the earth connection E/KE
  • Self test at device start with automatic notification in the event of a fault
  • iso1685FR: RS-485 interface (BMS bus) to output measured values and for configuration
  • iso1685FRM: RS-485 interface (BMS bus and Modbus RTU; can be switched using the DIP switch)
  • The BMS bus is used to output measured values and for configuration of the device
  • Modbus RTU is used to communicate with the Modbus-analogue converter M-7024. By means of the converter, the iso1685FRM provides an analogue output
  • μSD card with data logger and history memory for alarms
  • Protection against unauthorised or accidental parameter changes
  • Systems with very low leakage capacitance Ce ≤ 200 nF where very fast alarm response is necessary.
  • See Wiring diagram


Varianten van ISOMETER® iso1685FR / iso1685FRM

TypeNominale netspanningVoedingsspanningResponse valueOverigArt. Nr.
iso1685FR-5250…5 kV18…30 V10…1000 kΩBMS communicationB 9106 5800
iso1685FRM-5250…5 kV18…30 V10…1000 kΩBMS/Modbus RTU communicationB 9106 5804

Downloads voor ISOMETER® iso1685FR / iso1685FRM



Categorie Product Taal Datum Formaat Download