1. Prepare Tools and Equipment
Basically, you'll need the following:
Granta light barrier protection device (transmitter + receiver)
Bracket/mounting hardware
Electric drill, screwdriver, wrench
Connection cables, power cord
Punch press control box wiring diagram
2. Positioning the installation
The light barrier should be installed directly in front of the punch press, right where workers operate and place materials. Generally, the transmitter and receiver should be installed on the left and right sides, with no obstructions between them.
Key Mistakes to Avoid:
Height: Generally, install approximately 200mm to 500mm from the work surface, depending on the size of your product and the punching position.
Distance: Ensure both ends of the light barrier are aligned and not tilted, otherwise the infrared beams will misalign and trigger an alarm.
Angle: Try to install the light barrier vertically; avoid tilting the mounting angle, as this will result in inaccurate sensing. Some models are mounted top-down, on either side of the punch, but most models are designed for left-to-right directional transmission.
3. Wiring: Route the circuit with caution.
The next key step is wiring. Most Granta light curtains have three or five wires (depending on the model):
Brown: Positive (+24V)
Blue: Negative (0V)
Black/White: Signal output
Some also have control relay wires or fault alarm wires.
You need to connect the signal wires to the press's control circuit, usually to the emergency stop circuit or control relay. Once the light curtain is blocked, the control circuit is disconnected, and the press automatically stops.
Note: This step should not be connected randomly. Refer to the original wiring diagram for your press, and it is best to have a professional electrician perform this.
4. Commissioning and Trial Run
After installation, commissioning is required.
The method is simple:
Turn on the power and check if the light curtain's alarm light illuminates. A solid red light indicates misalignment.
Block the light curtain with your hand to see if the press immediately shuts down.
Test several times to ensure sensing at different heights and angles.
Some light curtains have a "self-test" function that checks for proper operation upon powering on. Make sure the light curtain is functioning properly before using it.