Ground Monitor Interrupter
The ground monitor interrupter allows the installer to select different early monitor options. Wall Connector continuously checks for the presence of a safe earth connection and automatically recovers from faults. Earth assurance operates by injecting a small amount of current into the earth conductor in order to measure the impedance between line and earth. If high impedance is detected, the Wall Connector will lock out charging and display an error code of two (2) red blinks. See Error Codes for a full list of error codes.
For earth assurance to operate on TN grids, one leg of the distribution transformer must be earth-bonded (Neutral). Earth bond should only occur at one location in a site's electrical system.
Wall Connector earth assurance may be adjusted in countries with TT or IT grid configurations and can be disabled in the commissioning procedure.
The Earth Monitor Interrupter feature monitors the Wall Connector earth connection. Select the correct option based on the installation's earthing system and earth impedance.
- Enable: Earth connection will be monitored and a high detected earth resistance will disable the Wall Connector. This is the preferred setting to provide protection and should be selected where earth connection is expected to be strong (as in the case on TN networks and most TT networks), and where required by regulation.
- Disabled: Earth connection will not be monitored. This should be selected where the earth 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 earth faults or utility power surges are resolved automatically.