For the purposes of the distribution of power to the load with a higher current, the manufacturer has improved the ability of current-carrying relay contacts to reach hundreds of amperes. Rele which has a large current-carrying capability of this, commonly known as a contactor. Figure 2.13 shows the construction of the contactor.
Figure 2.13 Type Contactors
Contactors designed specifically for the purposes of distribution of power to the load (power switching) with larger currents. The ability of current-carrying contacts on the contactor varies depending on the load to be endured, typically range from tens to hundreds of amperes. Encoding different contacts on the contactor also uses only one digit as shown in Figure 2.14. Contact pair is used to supply power to the load is coded 1-2 or L1 – T1, 3-4 or L2 – T2, and 5-6 or L3 – T3.
Usually the contactor is also equipped with a pair of contact for purposes of control, in which the same encoding as pegkodean for the relay contacts.
Figure 2.14 Symbol Contactors
Rele used to implement a control sequence using boolean logic. Boolean logic is a way to make the decision to use a two-position or status. Status switch is in a position to open or close, disekspresikan sebaga logic zero (0) or one (1). This is how the digital computer works; in fact the name was taken from the status of discrete digital on / off. The first digital computer was built based on the electromagnetic relay, but this time the electromagnetic relay function has been replaced by semiconductor devices.