Nastyaer GIV50-11 limit switch

Ensure that the contact surface between the actuator and the switch is perpendicular to prevent lateral forces from causing internal mechanism jamming.

Wiring preparation: Open the switch junction box cover (usually the top cover) to expose the screw terminals. Use 0.5~1.0 mm ² multi strand flexible wires to crimp U-shaped or O-shaped terminals, or tighten them directly under screws.

Wiring according to the markings: GIV50-11 is a 1-way normally open (NO) contact, usually with two terminals: COM and NO (or labeled 1-2). Connect the 24V DC positive terminal to the COM through a load (such as a PLC input module), and connect the NO terminal to the other end of the load; Alternatively, the switch can be directly connected in series into the control circuit.

Grounding: The metal casing should be grounded to prevent electric shock and electromagnetic interference.

Inspection and Testing: Manually press the actuator and measure the conductivity between COM-NO using a multimeter in the resistance range (resistance close to 0 Ω); After release, it should be an open circuit (infinite). Attention: The switch is normally open and does not conduct when not activated.

4.2 Typical Wiring Diagram

text

[PLC DI]

|24V DC+-----------------------------------------24V DC-|COM

The actual wiring should follow the original equipment drawings. If the switch is used to directly control the relay coil, the coil must be connected in parallel with a freewheeling diode (such as 1N4007) to absorb the back electromotive force, otherwise it will burn out the contacts.

4.3 Precautions

Cable management: The lead wires should be fixed to avoid being pulled or worn out by moving parts on the insulation layer.

Sealing: The sealing gasket of the junction box cover should be intact, and the screws should be tightened to prevent dust from entering.

Torque: The torque of the wiring screw is about 0.5 N · m, and excessive torque can cause the wire to slip.

Operating principle and signal logic

The GIV50-11 is equipped with a mechanical self resetting micro switch inside. When no external force is applied, the moving contact is disconnected from the normally open terminal, and the circuit is not connected; When the external mechanical stopper presses down on the actuator, the internal spring quickly switches, pushing the moving contact to make contact with the normally open terminal and closing the circuit. After releasing the actuator, the spring resets and the contacts disconnect again.

Signal timing:

Action point (OP): The stopper begins to contact the actuator and move until the contact point flips over, typically at a distance of 0.5~2 mm.

Differential travel (DT): The travel difference between the action point and the reset point, ensuring that the contacts have sufficient backlash to avoid shaking.

Overtravel (OT): The maximum safe distance that allows the actuator to continue pressing beyond the action point. The stroke of GIV50-11 should not exceed 1.5 mm, otherwise the internal mechanism may be damaged.

For PLC systems, the NO contact is usually connected to the 24 V DC circuit of the digital input module. When the limit switch is triggered, the input signal changes from 0 V to 24 V (or vice versa, depending on the wiring). If using relay conversion, the contact life needs to be considered.

Maintenance and lifespan prediction

6.1 Regular Maintenance Plan

Periodic inspection project standards/tools

Monthly appearance cleaning, removing oil stains, dust, soft cloth, compressed air

Tighten the wiring terminals every quarter, check the cable insulation screwdriver and megohmmeter

Check the wear of mechanical actuators every six months, measure the action stroke with a feeler gauge and marking line

The annual contact resistance measurement (when closed) using a micro ohmmeter or multimeter should be less than 50 m Ω

Replace as a whole according to the working conditions when the number of actions approaches the mechanical life (usually 1 million times) or when contact welding occurs

6.2 Factors affecting lifespan

Switching frequency: If the action exceeds 60 times per minute and the contact wear accelerates, it is recommended to use a contactless proximity switch as a substitute.

Load type: The arc generated by inductive loads (relays, solenoid valves) will shorten the contact life. The Imax=0.4 A of GIV50-11 is the value under resistive load; The inductive load should be reduced to 0.2 A and a buffer circuit should be added.

Environmental temperature: Exceeding 50 ℃ can cause plastic parts to deform and lubricating grease to evaporate, resulting in poor operation.

Mechanical shock and vibration: Excessive vibration can cause instant disconnection of contacts, resulting in false signals, and vibration reduction brackets should be installed.

Practical cases of troubleshooting

7.1 Fault phenomenon: The limit switch does not operate, and the equipment crosses the limit, causing mechanical collision

Troubleshooting steps:

After power off, manually press the actuator and use a multimeter to measure whether the COM-NO is conducting. If it does not conduct, it can be determined that the internal contacts of the switch are burnt or mechanically stuck → replace the switch.