Ground Assurance
Wall Connector continuously checks for the presence of a safe ground connection and automatically recovers from faults. Ground assurance operates by injecting a small amount of current into the ground conductor in order to measure the impedance between line and ground. If high impedance is detected, the Wall Connector will lock out charging and display a fault code of two (2) red blinks. See Fault Codes for a full list of fault codes.
For ground assurance to operate on TN grids, one leg of the distribution transformer must be ground -bonded (Neutral). Ground bond should only occur at one location in a site's electrical system.
Wall Connector ground assurance may be adjusted in countries with TT or IT grid configurations and can be disabled in the commissioning procedure.
The Ground Monitor Interrupter feature monitors the Wall Connector ground connection. Select the correct option based on the installation's earthing system and earth impedance.
- Enable: Ground connection will be monitored and a high detected. Ground resistance will disable the Wall Connector. This is the preferred setting to provide protection, and should be selected where ground connection is expected to be strong (as in the case on TN networks and most TT networks), and where required by regulation.
- Monitor: Ground connection will be monitored but a high detected ground resistance will not disable the Wall Connector. This should be selected if the ground monitoring check yields false positives and ground impedance cannot be improved (as is the case in some TT networks).
- Disabled: Ground connection will not be monitored. This should be selected where the ground connection is not made (as is the case for IT networks), or where the current induced by this check would be problematic (as is the case on some TT networks with sensitive residual-current devices).
Temporary problems such as ground faults or utility power surges are resolved automatically.