A movable guard needs its position monitored, and sometimes needs to stay shut until the hazard has actually stopped. The decision between simple interlocking and guard locking follows from the machine run-down time, the risk of someone being trapped inside, and how often the guard is opened.
These families are grouped by the problem they solve rather than alphabetically. The first question is always whether the guard has to remain locked.
Coded, non-contact switches for guard position and general position monitoring, where defeating the guard with a spare actuator must be made difficult.
Non-contact magnetic switches for guard position and general position monitoring, where alignment tolerance matters more than coding.
Mechanical safety switches tripped by the guard itself, bringing the hazardous movement to a standstill when the guard opens.
A complete solution combining a hinge and a safety switch in one component, so the monitoring point sits at the pivot rather than on the leading edge.
Electromagnetic guard locking combined with safety gate monitoring, holding the guard shut to protect the process rather than to restrain a person.
Safe interlocking and safe guard locking in a single device, for machines where hazardous movement continues after the stop command.
An integrated safety gate system that combines safe guard locking with compatible control elements in one product, saving separate mounting.
A pushbutton unit for operating safety gate switches and systems, with variants that integrate PITreader so permissions can be checked before the command is accepted.
Answer these in order. Locking requirement and the reason for locking are the two decisions that determine everything else.
| Guard situation | Locking required? | Process or personnel? | Coding requirement | Recommended Safety route |
|---|---|---|---|---|
| Movement stops before the guard can be reached | No | — | Standard | PSENmag or PSENmech |
| Guard could be defeated with a spare actuator | No | — | Coded | PSENcode |
| Hinged gate or flap, switch should be concealed | No | — | Device dependent | PSENhinge |
| Opening mid-cycle would spoil the process | Yes | Process | Device dependent | PSENslock 2 |
| Hazardous movement continues after the stop | Yes | Personnel | Device dependent | PSENmlock |
| Locking plus local operator controls needed | Yes | Both | Device dependent | PSENmgate, or PSENmlock with PITgatebox |
| Only authorised staff may open the guard | Situation dependent | — | — | PITgatebox with PITreader |
The same guard hardware behaves differently depending on run-down, access frequency and who is expected to open it.
Perimeter fencing with one or more access doors, each monitored and evaluated, with a reset that cannot be reached from inside the cell.
Where movement continues after the stop command, the guard must stay locked until standstill is confirmed rather than released on the command alone.
Setup and maintenance access where only trained personnel should be able to unlock the guard, and where entry needs to be recorded.
Guard hardware is mechanical as well as electrical. Both sides have to be confirmed before a device can be proposed.
Guard monitoring produces a signal. Whether the machine actually reaches a safe state depends on the evaluation, the output stage and the reset arrangement being designed as one function.