When we wire, the copper wire of the wire will break and fall off because it is inserted into the wiring hole, which not only has a potential safety hazard, but also affects the conductivity, voltage and current of the wire itself, causing errors in the entire control system. To this end, we can insert all wires into copper tube terminals of corresponding size, and then insert the terminals into the corresponding relay wiring holes after crimping, so as to avoid the damage of conductive copper wires in wires and the resulting series of problems.