The 3LD2504-0TK51 with MAIN CONTROL SWITCH, 3POLE manufactured by Siemens is a three-pole main control switch, which is used to connect and disconnect the main supply line. It is equipped with insulation class I type of protection to ensure electrical safety. It contains an LED indicator and a window of a transparent cover to provide visual indication of the switching status. Its range of rated operating current is 16A to 125A and the rated cosine power factor is 0.8-1. The rated voltage is 550V and the rated insulation voltage is 600V. The operating temperature range of this switch is -20~+60? and its conforms to the standards of IEC 60947-3 and EN 60947-3.