Wiring method of three-wire proximity switch:
For the three-wire NPN proximity switch, the brown wire is connected to one end of the load and the positive pole of the power supply; The black line is a signal line connected to the other end of the load; The blue line is connected to the negative pole of the power supply.
Three-wire PNP proximity switch, brown wire connected to the positive pole of power supply; The black line is a signal line connected to one end of the load; The blue line connects the other end of the load and the negative electrode of the power supply.
Extended data:
1) Proximity switch has the difference between two-wire system and three-wire system. Three-wire proximity switch is divided into NPN type and PNP type, and their wiring is different.
2) The wiring of the two-wire proximity switch is relatively simple, and the proximity switch is connected to the power supply after being connected in series with the load.
3) Wiring of the three-wire proximity switch: the red (brown) wire is connected to the positive end of the power supply; The blue wire is connected to the 0V end of the power supply; The yellow (black) line is a signal and should be connected to the load. The other end of the load is connected as follows: for the NPN proximity switch, it should be connected to the positive end of the power supply; For PNP proximity switch, it should be connected to 0V terminal of power supply.
4) The load of proximity switch can be signal lamp, relay coil or digital input module of programmable controller PLC.
5) Special attention should be paid to the selection of the three-wire proximity switch connected to the PLC digital input module. Generally, PLC digital input modules can be divided into two categories: the common input terminal of one category is the negative electrode of power supply, and the current flows out of the input module.
At this time, you must choose the NPN proximity switch; Another common input terminal is the positive pole of power supply, and current flows into the input module. At this time, PNP proximity switch must be selected. Don't make the wrong choice.
References:
Baidu encyclopedia: proximity switch