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 ISOSCAN® EDS440 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 EDS440. 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: 2…10 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 display 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® EDS440

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
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
Application brochures Selectief aardfout zoeksysteem EDS 933.7 KB NL13.05.2019 10:31:28
Product Change Notification EDS44x change of frontplate for new addressing concept 135.8 KB EN13.05.2019 10:31:55D00201
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® EDS440


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 EDS440

TypeInternal diameter/mmDesign typeArt. no.
CTAC20ø 20circularB98110005
CTAC35ø 35circularB98110007
CTAC60ø 60circularB98110017
CTAC120ø 120circularB98110019
CTAC210ø 210circularB98110020
WS20x3020 x 30split-coreB98080601
WS50x8050 x 80split-coreB98080603
WS80x12080 x 120split-coreB98080606

Alternative measuring current transformer from the Bender program

TypeInternal diameter/mmDesign typeArt. no.

Measuring current transformer for EDS440-LAF

TypemmDesign typeArt. no.

ISOSCAN® EDS440 Variants

TypeSupply voltage US*Response valueLED displayOption "W"Art. no.
EDS440-S-1DC 242…10 mA----B91080201
EDS440W-S-1DC 24 V2…10 mA--B91080201W
EDS440-L-4AC/DC 24…240 V2…10 mA--B91080202
EDS440W-L-4AC/DC 24…240 V2…10 mAB91080202W
EDS440-LAF-4AC/DC 24…240 V10 mA--B91080209

*Absolute values