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ISOMETER® isoCHA425HV mit AGH420-1

ISOMETER® isoCHA425HV with AGH420-1

  • Switchable between CCS (Combined Charging System) and CHAdeMO
  • Nominal voltages up to DC 1000 V
  • Detection of symmetrical and asymmetrical insulation faults
  • Electrically isolated Modbus RTU interface
  • Display of the fault location (DC+/DC/balanced)

The ISOMETER® isoCHA425HV in combination with the coupling device AGH420-1 monitors the insulation resistance RF for DC fast charging stations according to CHAdeMO standard or according to Combined Charging System (CCS) for nominal system voltage ranges between DC 0 V and 1000 V.

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.

Please heed the limits of the area of application indicated in the technical data. Any use other than that described in this manual is regarded as improper.


  • Monitoring of the insulation resistance RF of DC charging stations according to CHAdeMO standard or Combined Charging System (CCS) in the system voltage range up to 1000 V
  • CHAdeMO (Mode CHd and CHA):
    – Maximum system leakage capacitance 1.6 μF per conductor
    – Detection of insulation faults in the system voltage range 50 V to 1000 V
    – One-pole insulation faults RFU: RFU≤ 100 kΩ: Response time ≤ 1 s, 100 kΩ < RFU≤ 2 MΩ: Response time ≤ 10 s – Two-pole insulation faults RFS: RFS ≤ 160 kΩ: Response time ≤ 10 s, RFS > 160 kΩ (200 kΩ): no detection (Deactivation) (only CHd)
  • CCS (Mode dc):
    – Detection of insulation faults up to 2 MΩ with a response time of 10 s
    – Maximum system leakage capacitance 5 μF
  • Measurement of the system leakage capacitance Ce
  • Measurement of the nominal system voltage Un (True RMS) with undervoltage/overvoltage detection
  • Measurement of the DC residual voltages UL1e (between L1/+ and earth) as well as UL2e (between L2/- and earth)
  • Selectable start-up delay, response delay and delay on release
  • Two separately adjustable response value ranges of 5...600 kΩ (Alarm 1, Alarm 2)
  • Alarm signalling via LEDs (“AL1”, “AL2”), a display and alarm relays (“K1”, “K2”)
  • Automatic device self test with connection monitoring
  • Selectable N/C or N/O relay operation
  • Measured value indication via a multifunctional LC display
  • Fault memory can be activated
  • RS-485 (galvanically isolated) including the following protocols:
    – BMS interface (Bender measuring device interface) for data exchange with other
  • Bender components
    – Modbus RTU
    – IsoData (for continuous data output)
  • Password protection to prevent unauthorised parameter changes
  • Stop mode to deactivate the measuring pulse generator


  • DC charging stations for electric vehicles in accordance with the Japanese charging standard CHAdeMO
  • DC charging stations for electric vehicles according to CSS (Combined Charging System) in compliance with IEC 61851-23

ISOMETER® isoCHA425HV with AGH420-1 Variant(s)

TypeNominal system voltage UnArt. No.**
isoCHA425HV-D4-4 + AGH420-1DC 0 (50*)…1 000 VB71036396

* Value for CHAdeMo
** (B7… = push-wire terminal / B9… = screw-type terminal)

Optional Accessories for ISOMETER® isoCHA425HV with AGH420-1

TypeArt. No.
Mounting clip for screw mounting (one piece per device)B98060008
Mounting frame XM420B990994 

Downloads for ISOMETER® isoCHA425HV with AGH420-1

CE Declarations of conformity isoXX425 151.9 KB 2023/01/09 06:50:5109.01.2023 06:50:51
Datasheets isoCHA425HV 441.8 KB DE2021/11/11 06:48:3711.11.2021 06:48:37D00404
Datasheets isoCHA425HV 437.1 KB EN2021/11/11 06:48:4511.11.2021 06:48:45D00404
Flyer isoCHA425HV 296.5 KB DE2021/09/07 09:04:4307.09.2021 09:04:43D00404
Flyer isoCHA425HV 295.9 KB EN2021/09/07 09:04:5807.09.2021 09:04:58D00404
Manuals isoCHA425HV 2.1 MB ES2021/11/12 10:31:0712.11.2021 10:31:07D00404
Manuals isoCHA425HV 2.1 MB EN2021/11/12 10:31:1312.11.2021 10:31:13D00404
Manuals isoCHA425HV 2.1 MB DE2021/11/12 10:31:0712.11.2021 10:31:07D00404
Flyer isoCHA425HV (US) 794.2 KB EN2021/03/11 18:16:0611.03.2021 18:16:06
Quickstarts isoCHA425HV 1.2 MB DE2021/11/12 10:31:2612.11.2021 10:31:26D00404
Quickstarts isoCHA425HV 1.2 MB EN2021/11/12 10:31:2612.11.2021 10:31:26D00404
Software Modbus RTU - Monitor isoxx425 V2.2.2 setup 7.1 MB 2019/05/13 10:31:5913.05.2019 10:31:59