How to Install the Safety Curtain Correctly
So, have you installed the safety grating or safety light curtain correctly? How to install the safety light curtain to really achieve the protective effect?
First of all, let’s ask some experts a question: How do you connect the signal of your safety grating/safety light curtain? On the safety relay, or on the PLC, or on the ordinary relay? Presumably most engineers are basically connected to the PLC, some are connected to ordinary relays, and some are connected to the emergency stop switch, but these are basically wrong connections. The real four-level protection or even two-level, the safety grating needs to be connected to the safety relay. Then connect the signal of the safety relay to the control circuit of the machine equipment.
Safety grating/safety light curtain is literally known to play a role in safety protection in special occasions. If it can’t play the role of safety protection, it is better not to install it in case that it should give the operator an illusion there is safety protection. As a result, more potential accidents will occur.
Safety Grating is Divided into Level-2 and Level-4
The Working Principle of the Level-2 Safety Grating is As Follows
1: It is a safety circuit.
2: Single loop, with self-test.
3: Meet the safety requirements by means of periodic self-checks, a fault may lead to the loss of the safety function, which can be detected in a working cycle.
The Working Principle of the Level-4 Safety Grating is As Follows
1: It is a safety circuit.
2: Double-loop, with self-check, mutual check, any action requires double confirmation.
3: Using guaranteed safety components and international standard safety technology, when one or more of them fail, the safety function will not be lost, and the safety function will always exist. In short, double-loop, self-testing.
In Sum: Periodic Self-checking Single-loop General Safety Light Grids and Area Sensors Work
1: Single-circuit, not single-circuit.
2: Without self-inspection, the light curtain is broken but can’ t be checked in details causing hidden dangers in safety protection. So it is better not to install it.
3: It is not a safety circuit, and some even do not have a CPU, which is relatively poor in resisting strong electromagnetic interference, sunlight interference and arc light disturbance.
To sum up, it is recommended that you choose a level-4 or level-2 safety grating and connect it to a safety relay. Of course, due to its cost considerations, many engineers still connect the light curtain directly to the PLC or ordinary relays. Even so, they must choose high-quality domestic safety gratings.
If you want to know more about the application of safety grating/safety light curtain, contact DATAVISION Intelligent Equipment, we would like to recommend the best application solution for you.