The mechanical limit switch is a staple in automation. The switch detects the presence and position of objects by making direct contact with a target. But this direct contact can cause wear on the mechanical parts of the limit switch and cause reliability issues with its object detection capabilities. With limit switch style inductive sensors from Pepperl+Fuchs, non-contact sensing of targets is possible.
Limit switch style inductive sensors are designed for use in manufacturing and conveyor lines across a variety of industries. Customers prefer these proximity sensors for their rugged construction, reliability, and versatility. The sensors are available in several different versions, which include the following housing styles:
L2: cube-style housing (40 × 40 × 40 mm)
L2: cube-style with M12 connector
U2 or U4: 5-way limit switch style housing (40 × 40 × 120 mm)
U2: plastic base ½ NPT conduit entrance
U4: metal base ½ NPT conduit entrance
The versions with a conduit entrance have screw terminals for wire connection, and the L2 version has a standard quick-disconnect M12 connector. Though there are many differences, the U2, U4, and L2 all have a 5-way rotatable sensor head and the same mounting pattern for easy replacement.
However, a different method is required for rotating the head on each sensor. The cube-style sensor features a locking clip that must be removed before the sensing head can be adjusted, and the limit switch style sensor has two screws that must be loosened to remove and swivel the sensing head into the proper position. Rotate each type of sensing head as follows:
Unlock the flip lever clip on the mounting bracket to allow the sensor to be adjusted.
Remove the sensor from the mounting bracket.
Hold the sensor by the connector.
Rotate the sensor face by turning it 90 degrees.
Once the sensing face is rotated, reattach the sensor to the mounting bracket with the sensing face in the required orientation.
Loosen both screws on the top of the sensor.
Next, lift up the two screws to release the sensor head. Note: the two screws are captive and will remain in the locking cube; they must be fully extended to remove the sensing head.
While holding the sensor, pull up and out on the sensing head to release it from the housing.
It may be easier to hold the sensor sideways or upside down so the captive screws remain in the extended released position.
The sensor should look like this when the head is released.
Next, rotate the sensing face up to 90 degrees.
Once rotated, the sensor should look like this.
Put the sensing head back into the housing in the desired direction by pushing it in and down. Both screws must be fully extended.
Tighten both screws to secure the sensor.