The line-voltage sensing submodule is an optional module for line-voltage sensing and correction.

The line-voltage sensing submodule is plugged from the front into the enclosure of the central interface module. The slot is located in the busbar area. If the line-voltage sensing submodule is not used, the opening is sealed by the busbar cover. If the line-voltage sensing submodule is used, the cover is used for shock-hazard protection.