How does a PEN Fault Device Protection work?

Keba chargers usually come with a Protective Earth and Neutral (PEN) device, which is fully automatic and requires no intervention or setting to operate correctly. This means that the unit should not be power cycled to reset it.

When power is initially applied, there is a 2 second power on delay built into the electronic circuitry. During these 2 seconds period, the green status LED will flash, and no power will be applied to the electric vehicle charging equipment side of the device.

After the 2 seconds power on delay, the green status LED will become permanently lit and the 3 pole contactor will be closed to allow power to be applied to the electric vehicle charging equipment.

The device will then continually monitor the voltage presented to the input side of the device and the green status LED will remain permanently lit unless there is a fault detected or there is a power failure on the input side of the device.

There could be 2 different types of faults:

1. If a high voltage fault is detected (voltage greater than 253VAC), the device will allow this fault to persist for no more than 3 seconds after which it will open the contactor, removing power from the electric vehicle charging equipment, and will start to flash the red status LED with a constant on/off cycle.
2. If a low voltage fault is detected (voltage less than 207VAC), the device will allow this fault to persist for no more than 3 seconds after which it will open the contactor, removing power from the electric vehicle charging equipment, and will start to flash the red status LED using a fast irregular on/off cycle.

Once a fault condition is removed, the device will remain in a recovery state for 30 seconds, during which time it will flash the green status LED. Any grid fault detected during this time will reset the reset timer. After this time, the contactor will be closed, restoring power to the electric vehicle charging equipment, and the green status LED will once again be lit permanently.

Should a power cut occur the green status LED will be extinguished, and the contactor will be opened. Once power is restored and provided no fault is no fault detected, the device will operate as though power has been initially applied as described above.