Innovative technologies for safe handling of electrical power to achieve high availability

We offer you first-class quality and safety combined with global service and every support in resolving your monitoring problems.

  • Electrical safety for unearthed power supplies (IT systems)
  • Insulation monitoring equipment, insulation fault location systems
  • Power supplies for medical applications
  • Measuring and monitoring relays
  • Electrical safety for earthed power supplies (TN systems)
  • Using renewable energies efficiently: wind power, photovoltaics
  • Test systems for electrical equipment and medical technology


  • Automatic insulation fault location
  • Application main circuits
  • 12 measuring channels for measuring current transformers
  • CT connection monitoring
  • Universal system concept

The insulation fault locators EDS460/490 in combination with the ISOMETER® iso685-D-P are applied for localising insulation faults in unearthed systems (IT systems). The locating current signals generated by the insulation monitoring device ISOMETER® iso685-D-P are detected by measuring current transformers and evaluated by the insulation fault locators. Up to 12 measuring current transformers can be connected to one EDS460/490. A total of 90 EDS insulation fault locators can be connected via one RS-485 interface (BMS protocol). Hence, up to 1080 circuits can be monitored. The maximum scanning time is 10 s.


  • Insulation fault location in IT systems
  • For AC, 3AC, DC and IT systems
  • Control and display function in a single device (EDS…-D)
  • 12 measuring channels (circuits) for measuring current transformers of the CTAC, WR, WS series
  • Up to 90 EDS insulation fault locators in the system (1080 measuring channels)
  • Scanning time max. 10 s for all measuring channels (parallel scanning)
  • Response sensitivity
    - EDS460/490 2…10 mA,
    - EDS461/491 0.2…1 mA
  • History memory to store 300 events
  • Two alarm relays with one changeover contact each
  • N/O or N/C operation, selectable
  • Connection external test/reset button
  • Indication via graphical display resp. 7-segment display and alarm LEDs
  • BMS address range 1…90
  • Serial interface RS-485
  • Continuous CT connection monitoring
  • Fault memory behaviour selectable
  • Device version EDS490/491 with one alarm contactor per channel
  • Additional AC residual current measurement


  • Insulation fault location in AC, AC/DC and DC IT systems
  • Main and control circuits in industrial plants and ships
  • Diode-decoupled DC IT systems in power stations
  • Systems for medical locations

Downloads for ISOSCAN® EDS490-D

Handbücher EDS460/490 - EDS461/491 3.8 MB DE13.05.2019 10:31:41D00085
Handbücher EDS460/490 - EDS461/491 4.0 MB EN13.05.2019 10:31:48D00085
Handbücher EDS460/490 - EDS461/491 1.8 MB ES13.05.2019 10:31:54D00085
Handbücher EDS460/490 - EDS461/491 1.2 MB FR13.05.2019 10:31:54
Datenblätter EDS460/490 - EDS461/491 693.5 KB DE13.05.2019 10:31:34D00085
Datenblätter EDS460/490 - EDS461/491 647.4 KB EN13.05.2019 10:31:35D00085
Datenblätter EDS460/490 - EDS461/491 645.2 KB ES13.05.2019 10:31:37D00085
Datenblätter EDS460/490 - EDS461/491 985.2 KB ZH13.05.2019 10:31:33
Handbücher EDS49x 593.7 KB DE12.10.2021 07:28:48D00085
Handbücher EDS49x 593.7 KB EN12.10.2021 07:28:48D00085
Anwendungsbroschüren Selectief aardfout zoeksysteem EDS 933.7 KB NL13.05.2019 10:31:28
Flyer Industrial EDS Flyer 1.1 MB EN28.04.2021 13:38:13
Flyer Healthcare EDS Flyer 1.7 MB EN29.04.2021 15:23:15
Produktbroschüren Mining Brochure 11.7 MB ES22.05.2020 14:37:31

Optional accessories for ISOSCAN® EDS490-D


TypeSupply voltage USArt. No.
DI-1DL (interface repeater)AC 85…260 V, 50…60 HzB95012047
DI-2USB (interface converter RS-485/USB)supplied by the USB port, no additional power supply required.B95012045

* Absolute values

Protocol converters

TypeSupply voltage USArt. No.
COM465IPAC/DC 24…240 V, 50…60 HzB95061065

Measuring current transformers for EDS460/490

TypeInside diameter/mmType of constructionArt. No.
CTAC20ø 20circularB98110005
CTAC35ø 35circularB98110007
CTAC60ø 60circularB98110017
CTAC120ø 120circularB98110019
CTAC210ø 210circularB98110020
WR70x17570 x 175rectangularB98080609
WR115x305115 x 305rectangularB98080610
WS20x3020 x 30split-coreB98080601
WS50x8050 x 80split-coreB98080603
WS80x8080 x 80split-coreB98080605
WS80x12080 x 120split-coreB98080606
WS80x16080 x 160split-coreB98080608

Alternative measuring current transformers from the Bender range

TypeInside diameter/mmType of constructionArt. No.

Measuring current transformers for EDS461/491

TypeInside diameter/mmType of constructionArt. No.
WS20x30-800020 x 30split-coreB98080602
WS50x80-800050 x 80split-coreB98080604

Alternative measuring current transformers from the Bender range

TypeInside diameter/mmType of constructionArt. No.
WS20x30/800020 x 30split-coreB911764
WS50x80/800050 x 80split-coreB911757
W10/8000-610circular, 6xB911900

ISOSCAN® EDS490-D Variants

TypeSupply voltage US*Response valueArt. No.
EDS490-D-1DC 16…94 V / AC 16…72 V, 42…460 Hz2…10 mAB91080009
EDS490-D-2AC/DC 70…276 V / AC 42…460 Hz2…10 mAB91080010

*Absolute value