2TLC172245M0201, rev. B
6
www.abb.com/jokabsafety
2013-04-22
Function description
Safety interlock switches with guard locking are designed to fit to the leading edge of sliding or hinged guard doors
to provide positively operated switching contacts and provide a tamper resistant key mechanism. They are
designed to provide robust position interlock detection and to keep closed of moving guards. The switch is rigidly
mounted to the frame of the guard or machine. The actuator is fitted to the moving part of the guard and is aligned
to the switch entry aperture. The actuator profile is designed to match a cam mechanism within the switch head
and provides a positively operated not easily defeatable interlock switch. When the guard is closed, the actuator
inserted in the switch and the switch locked, the machine can be able to start. When the solenoid is energised
(MKey8, MKey8Z, MKey8ER) the safety contacts are positively opened, and the guard door can be opened.
The MKey8 is available in two basic versions, either with a spring lock or an electro-magnetic lock. In the spring
lock version, the locking mechanism moves into the locked position directly when the door is closed and the
actuator key is pushed into the switch. The actuator key can only be released and the gate opened by supplying
operating voltage to the solenoid (A1-A2).
MKey8M is an electro-magnetic lock version, the locking mechanism is only in the locked position when the
solenoid (A1-A2) is supplied with operating voltage. Release of the actuator key is only possible when the
operating voltage is not applied to the solenoid (A1-A2). The solenoid voltage can be 24VDC or 230VAC
depending on choice.
The MKey8ER has an escape rear release “unlocking” facility to enable the actuator key to be released without the
energisation of the solenoid (A1-A2).
The MKey8 has double forced disconnection contacts connected to the actuator key and the locking mechanism.
The actuator key is designed to prevent tampering with tools, magnets or similar objects. To achieve highest safety
level in connection with the machine control system it is recommended that the MKey8 is monitored by an
appropriate ABB Jokab Safety safety relay, Pluto safety PLC or Vital system. To obtain the highest level of safety,
two switches per gate are required.
Warning!
Application consideration must be given to the fixing of the actuator which has to be in a way that
prevents disassembly by easy means.
Hinged guard
Sliding guard
