User Manual

SAFETY
Safety handbook page - 20 -
PNSPO
Operation key operated actuation
The operation key operated switch is designed to prevent
easy cheating of the switch.
Dedicated operation key is needed every time.
These switches can be used on sliding, hinged and lift-off
guards. Mainly they are used in interlocking switches.
Disadvantage in these switches is that it can be defeated by
using a operation key which is not attached to the guard.
Preventing this kind of defeat is possible and it
can be achieved by:
- Physical obstruction or shielding preventing
introduction of spare actuators
- Permanent assembly (by welding, riveting, “one way” screw”)
of the operating key with the guard to render dismantling more difficult.
Hinge operated actuation
In hinged door switches it is very difficult to defeat the
switch. That is very good features of hinged door switches.
Another feature is easy use in small size guards, where key
operated switches can not be used due to operation key
radius. Care must be taken for large wide guard doors
because of opening angle is resulting in a bigger movement
of the door. That can result a significant gap in the opening
edge on very wide guard doors.
5.4 Schematics
Below you will find some door monitoring application examples.
G9SB-3012-A 24V ACD/DC
- category 4
- auto reset
S1: Safety switch with
direct Opening (D4Dx, D4Bx)
S2: Limit switch (D4DN, D4BN)
KM1/KM2: Contactor
M: 3 phase motor