The EPS Box, in accordance with the provisions of the standard (cf. 3), allows you to use the inverter for emergency services in the absence of the grid, allowing the loads to be powered both from the public network and the power production installation . EPS Box-TP integrates two contactors which provides simple connection for users. On the packing list there is a board marking paper made of cardboard to indicate where the X3-EPS Parallel Box should be mounted on the wall. Step 1: Attach the corresponding. An Electrician must know Electrical Abbreviations and Full Forms to read a electrical drawings. Their compact build and integrated dual contactors simplify wiring and support flexible installation in any setup. With intelligent switching between on-grid and off-grid modes, the EPS Box. /H3 Smart.