First open the plug, and locate the inscriptions: 1, 2, 3 and 0 with a line on top of a T shape picture inside. Take the insulation wires, and strip about ¼ inch on the ends. Insert the wires according to the labeled slots: black goes in 1 or L1, red and blue in 2 or L2, white in 0 and green in the picture.
When wiring, use pliers to clamp down and strip the wire to ensure you don’t cut it or hurt your hands. Using a screw driver and screws, fix and tighten the wires in the sockets. Close the plug, making sure there are no loose wires or shaky pieces. Most three phase plugs have ground or earth connections but may not necessarily have the neutral one.
Power plugs come in different models and from various countries. It’s therefore common to come across some that don’t exactly fit in certain sockets. However, there are also some set according to international standards. The main difference seen when wiring is the color coding as it may not be similar to main plugs. In such a case, one needs to check the instructions of the model to do the wiring.