Contactless Coded Safety Switch

 2017-05-07 06:59 PM by
Contactless Coded Safety Switch

In 1993, Comitronic-BTI, supplied locally by RET Automation Controls, launched the first contactless, coded safety switches that could operate without a safety relay.  Today, new products such as the VIGILGUARD interlocking range are still being developed using the same technology.
Interlocking devices are solutions used to protect operators from dangerous machinery. They represent an important and fundamental element of the machine and should be integrated during the early stages of the machine design.

Comitronic-BTI markets many tamper-proof coded safety switches using the Actom3 process.  The Actom3 process is based on electronic monitoring and internal relays which negates the need for a separate safety module.  This solution is not only cost effective (as the external relay is not needed), but also simplifies electrical wiring and saves space in the electrical panel.   The high switching capacity of both safety circuits (2A/48V) is sufficient for most machines in industries such as packaging, palletising, woodworking, robotics, food industry and many more.  VIGILGUARD Interlocking Devices integrate the Actom3 process and as such benefit from this proven technology.
In the machine safety market, we find the traditional mechanical interlocking devices which require the alignment to be exact and often have a short life expectancy due to the breakage of the keys.  Another disadvantage of the traditional mechanical interlocks is that the actuating holes on the devices themselves do not comply with the demanding standards of food industry as bacteria can accumulate in the holes.
 
The VIGILGUARD coded contactless solution solves the challenges of the traditional interlock: when energised, the coded bolt is activated and inserted into the coded strike head.  The VIGILGUARD solution then guarantees that the door is closed and locked correctly by reading the code in the strike head, thereby confirming that the bolt is inserted into the correct strike head before actuating the safety contacts.  Due to the dead bolt design there is no mechanical wear; the mechanical lifetime expectancy is over 10,000,000 cycles.  The housing material, Zamak (Zinc-Aluminium-Magnesium-Copper), is very resistant to harsh environments and the rough handling experienced on heavy doors which are commonly used in automotive and steel industry.  The VIGILGUARD's smooth and hygienic design simplifies the cleaning process, as there is no cavity in the switch and the strike head has a central hole to quickly release any water.
 
Fitted with internal relays, VIGILGUARD achieves the highest safety level (PL4e according to ISO EN 13849-1, or Category 4 as per EN954-1), without having to be wired to a safety module.  The redundancy of the safety lines, self checking circuitry, inclusion of a manual reset and emergency manual unlocking system allows the VIGILGUARD to be totally independent and safe.

To ensure that the device is easy to wire, the redundant safety lines have a potential free switching capacity of 2A/48V, allowing them to be connected directly to most machines’ contactors.  The optional dual M12 connectors make wiring devices in series easy, while maintaining the same safety level.

The three LED's on the VIGILGUARD give to the operators an overview of the state of the switch.

  1. Power On / Door Unlocked - When the power supply is not in the correct range, or when the temperature of the device becomes abnormal, a visual indication is given via the LED and the VIGILGUARD automatically switches the machine into a safe state.
  2. Door locked
  3. Eco mode/standby.

 

Link to VIGILGUARD Interlock products in the Store