DC charging points in electric mobility are configured as unearthed power supply systems (IT systems). The ISOMETER® in the compact device isoEV425 with the related coupling device AGH420 monitors the insulation resistances of the stated systems and comply with the equipment standard IEC 61557-8. The actual insulation resistance is indicated on an LC display.
The isoEV425 is an insulation monitoring device for DC charging stations (mode 4 in accordance with IEC 61851-23:2014) for charging electric vehicles. During the charging process the charging station takes care of the electrical safety on both the charging station and the vehicle coupled. The ISOMETER® in the vehicle is normally deactivated in this situation.
Due to the active AMP measuring method, the DC side of the charging station can be monitored as far up as to the motor with AC 0…690 V, provided that all components in the system are galvanically connected with one another. Insulation faults that occur are signalled via the integrated relays, the alarm LEDs, as well as via the RS-485 interface. Here a differentiation is made between a factory-set prewarning value of 500 kΩ and a main warning of 100 kΩ.
The isoEV425 will be delivered as a package with the related coupling device. The ISOMETER® and coupling device are connected using four wires. Due to the supply of power separate to the system monitored, it is possible to monitor the de-energised IT system up to DC 1000 V and AC 690 V.
Benefits for the user:
The compact designs of the devices provide a flexible and cost-effective option for insulation monitoring. In practical operation this means:
- Insulation faults that occur are reliably signalled in accordance with the standards
- Space-saving version in the 2-module enclosure (36 mm)
- Space-saving coupling in the 2-module enclosure
- The two devices can be mounted in different positions in the switch cabinet or in different switch cabinets, they are connected using 4 wires
- Direct indication of the insulation resistance on the LC display
- Integrated alarm relay
- RS-485 interface for data transmission