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 control circuits
  • 12 measuring channels for measuring current transformers
  • CT connection monitoring
  • Universal system concept

The insulation fault locators ISOSCAN® EDS441 are used in connection with the ISOMETER® iso685-D-P or the locating current injector PGH to locate insulation faults in unearthed power supply systems (IT systems).

They detect locating current signals generated by the insulation monitoring device iso685-D-P  or the locating current injector PGH and evaluate them correspondingly. Up to 12 measuring current transformers can be connected to an EDS441. In total, up to 50 insulation fault locators can be connected via an RS-485 interface (BS bus protocol) and thereby up to 600 outgoing circuits can be monitored.


  • Universal system concept
  • Modular design, therefore easily adjustable to the given circumstances
  • Measuring current transformers available in various sizes and versions
  • CT connection monitoring
  • 12 measuring channels for measuring current transformer series CTAC…, WR…, WS…
  • Optional extension by 12 relay channels
  • Fault memory behaviour selectable
  • Up to 50 EDS insulation fault locators in the system, 600 measuring channels
  • Response sensitivity 0.2…1 mA
  • AC residual current measurement with configurable response value
  • Two alarm relays with one N/O contact each
  • N/O or N/C operation selectable
  • External test/reset
  • Central indication of faulty outgoing circuits
  • Serial interface RS-485, BS bus address range 2…79, Modbus RTU
  • Connection to higher-level control and visualisation systems possible


  • Insulation fault location in AC, 3AC and DC IT systems
  • Main circuits and control circuits in industrial plants and ships
  • Diode-decoupled DC IT systems in power plants
  • Systems for medical locations

Downloads for ISOSCAN® EDS441

Quickstarts EDS440/EDS441 2.0 MB DE13.05.2019 10:31:56D00201
Quickstarts EDS440/EDS441 2.0 MB EN13.05.2019 10:31:56D00201
Quickstarts EDS440/EDS441 2.0 MB FR13.05.2019 10:31:56D00201
Quickstarts EDS440/EDS441 2.0 MB ES13.05.2019 10:31:56D00201
Manuals EDS440/EDS441 41.9 MB ZH13.05.2019 10:31:40D00201
Datasheets EDS440/EDS441 2.4 MB ES13.05.2019 10:31:37D00201
Datasheets EDS440/EDS441 15.2 MB ZH13.05.2019 10:31:33D00201
Quickstarts EDS440/EDS441 977.8 KB ZH13.05.2019 10:31:56D00201
Manuals EDS440/EDS441 8.7 MB DE09.06.2022 10:46:29D00201
Manuals EDS440/EDS441 8.7 MB EN09.06.2022 10:48:21D00201
Datasheets EDS440/EDS441 1,017.6 KB DE02.11.2021 09:52:53D00201
Datasheets EDS440/EDS441 1,012.3 KB EN02.11.2021 09:53:15D00201
Product Change Notification EDS44x change of frontplate for new addressing concept 135.8 KB EN13.05.2019 10:31:55D00201
Manuals EDS440/EDS441 - Modbus-Einstellungen 186.8 KB DE14.01.2020 07:38:55D00201
Manuals EDS440/EDS441 - Modbus settings 189.8 KB EN14.01.2020 07:37:48D00201
Datasheets EDS441-LNA-KITS Datasheet (US) 5.8 MB EN26.05.2020 17:56:01D00201
Application brochures 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
Product Brochures Mining Brochure 11.7 MB ES22.05.2020 14:37:31

Optional accessories for ISOSCAN® EDS441


TypeSupply voltage USArt. no.
DI-1PSM (RS-485 repeater)AC/DC 24 V ± 20 %B95012044
DI-2USB (interface converter RS-485/USB) with USB cableSupplied by USB interfaceB95012045
IOM441-S (Input/Output module)12-fold relay moduleB95012057

Measuring current transformer for EDS441

TypeInternal diameter/mmDesign typeArt. no.

Alternative measuring current transformer from the Bender program

TypeInternal diameter/mmDesign typeArt. no.
W10/8000-610circular, 6-foldB911900
WS20x30/800020 x 30split-coreB911764
WS50x80/800050 x 80split-coreB911757

Measuring current transformer for EDS441-LAB

TypeInternal diameter/mmDesign typeArt. no.

ISOSCAN® EDS441 Variants

TypeSupply voltage US*Response valueArt. no.
EDS441-S-1AC/DC 24…240 V0,2…1 mA----B91080204
EDS441W-S-1AC/DC 24…240 V0,2…1 mA--B91080204W
EDS441-L-4AC/DC 24…240 V0,2…1 mA--B91080205
EDS441W-L-4AC/DC 24…240 V0,2…1 mAB91080205W
EDS441-LAB-4AC/DC 24…240 V0,2…1 mA--B91080207
EDS441W-LAB-4AC/DC 24…240 V0,2…1 mAB91080207W

*Absolute values