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  • Insulation monitoring device for medical IT systems
  • Load and temperature monitoring for IT system transformers
  • According to IEC 60364-7-710, IEC 61557-8 and 61557-9
  • Locating current injector for insulation fault location systems
  • Can be extended to operate as an insulation fault location system

ISOMETER®s of the isoMED427x-(PT) series monitor the insulation resistance of a medical IT system with AC 70…264 V. In addition, the load current and the temperature of the IT system transformer are monitored. Alarms and measured values are provided to other bus devices via the BMS interface. For display and signalling purposes, the use of special alarm indicator and test combinations is recommended.
After detection of an insulation fault, the internal locating current injector of the isoMED427P-(xx) models enables insulation fault location. The use of special devices of the EDS series is recommended to locate the insulation fault.
Devices of the isoMED427x-(PT) series do not require an additional supply voltage. The maximum permissible system leakage capacitance is 5 μF.
In order to meet the requirements of applicable standards, customised parameter settings must be made on the equipment in order to adapt it to local equipment and operating conditions.


  • Insulation monitoring for medical IT systems
  • Adjustable response value for insulation monitoring
  • Locating current injector for equipment for insulation fault location
  • Load and temperature monitoring for IT system transformers
  • Adjustable load current response value
  • Temperature monitoring with PTC thermistor or bimetal switch
  • Self monitoring with automatic alarm
  • PE connection monitoring
  • Internal/external test button
  • LEDs: Power On, Alarm 1, Alarm 2
  • Configurable alarm relay: N/O or N/C operation selectable
  • Compact two-module enclosure (36 mm)
  • BMS interface


  • Medical IT system in accordance with IEC 60364-7-710, IEC 61557-8, IEC 61557-9 and DIN VDE 0100-710

ISOMETER® isoMED427 Variant(s)

TypeSupply voltage USArt. N .**
isoMED427-2AC 70…264 V, 47…63 HzB72075306
isoMED427P-2 *AC 70…264 V, 47…63 HzB72075301
isoMED427P-PTAC 70…264 V, 47…63 HzB72075307

* Only this device has a Lloyds Register approval
**(B7… = push-wire terminal / B9… = screw-type terminal)

Optional Accessories for ISOMETER® isoMED427

TypeArt. No.
STW2 measuring current transformerB942709
ES0107/temperature sensor (PTC)B924186
Mounting frame XM420B990994
Mounting clip for screw fixing (one clip per device)B98060008

Downloads for ISOMETER® isoMED427

CE Declarations of conformity isoMED427P-2 88.8 KB 2022/10/24 05:54:3224.10.2022 05:54:32
Manuals isoMED427x-(PT) 2.5 MB DE2022/06/09 10:46:0409.06.2022 10:46:04D00440
Manuals isoMED427x-(PT) 2.5 MB EN2022/06/09 10:47:5609.06.2022 10:47:56D00440
Manuals isoMED427P 1.0 MB ES2019/05/13 10:31:5413.05.2019 10:31:54D00043
Manuals isoMED427P 443.2 KB FR2019/05/13 10:31:5513.05.2019 10:31:55D00043
Datasheets isoMED427x-(PT) 612.1 KB DE2022/06/23 13:22:3323.06.2022 13:22:33D00440
Datasheets isoMED427x-(PT) 609.5 KB EN2022/06/23 13:22:4323.06.2022 13:22:43D00440
Datasheets isoMED427P 419.6 KB ES2019/05/13 10:31:3713.05.2019 10:31:37D00043
Datasheets isoMED427P 527.7 KB ZH2019/05/13 10:31:3313.05.2019 10:31:33D00043
Manuals isoMED427P 1.1 MB ZH2019/05/13 10:31:4013.05.2019 10:31:40D00043
Quickstarts isoMED427x-(PT) 1.4 MB DE2022/07/04 07:30:1504.07.2022 07:30:15D00440
Quickstarts isoMED427x-(PT) 1.4 MB EN2022/07/04 07:30:1504.07.2022 07:30:15D00440