NBN EN 1088 : 1996 + A2 2008

Foreword
0 Introduction
1 Scope
2 Normative references
3 Definitions
3.1 Interlocking device (interlock)
3.2 Interlocking guard
3.3 Interlocking guard with guard locking
3.4 Guard locking device
3.5 Automatic monitoring
3.6 Positive mode actuation
3.7 Positive opening operation of a contact element
3.8 Stopping time (time for hazard elimination)
3.9 Access time (time for access to a danger zone)
4 Operating principles and typical forms of interlocking
     devices associated with guards
4.1 Interlocking principles
4.2 Typical forms of interlocking devices
4.3 Technological forms of interlocking devices
5 Provisions for the design of interlocking devices
     (independent of the nature of the energy source)
5.1 Actuation modes of mechanically actuated position
     detectors
5.2 Arrangement and fastening of position detectors
5.3 Arrangement and fastening of cams
5.4 Reducing the probability of common cause failures
5.5 Guard locking device
5.6 Delay devices
5.7 Design to minimize defeat possibilities
5.8 Environmental considerations
6 Additional technological requirements for electrical
     interlocking devices
6.1 Compliance with EN 60204-1
6.2 Interlocking devices incorporating mechanically actuated
     position switches
6.3 Interlocking devices incorporating non-mechanically
     actuated position switches (proximity switches and
     magnetic switches)
7 Selection of an interlocking device
7.1 General
7.2 Conditions of use and intended use
7.3 Risk assessment
7.4 Stopping time and access time
7.5 Frequency of access
7.6 Performance considerations
Annexes
A (informative) Guard-operated interlocking device with
     one single cam-operated position detector
B (informative) Guard-operated interlocking device with
     tongue-operated switch
C (informative) Direct (mechanical) interlocking between
     guard and start/stop manual control
D (informative) Captive-key interlocking device
E (informative) Trapped-key interlocking device
F (informative) Plug and socket interlocking device (plug/
     socket combination)
G (informative) Guard-operated interlocking device
     incorporating two cam-operated position detectors
H (informative) Mechanical interlocking between a guard
     and a movable element
J (informative) Electrical interlocking device
     incorporating magnetically actuated (magnetic) switches
K (informative) Electrical interlocking device
     incorporating two proximity detectors
L (informative) Pneumatic/hydraulic interlocking devices
M (informative) Interlocking device with spring applied/
     power released guard locking device
N (informative) Interlocking device with guard locking,
     with manually operated delay device
P (informative) Bibliography

Covers the parts of guards which actuate interlocking devices. Requirements for guards are given in prEN 953. The processing of the signal from the interlocking device to stop and immobilize the machine is dealt with in prEN 954-1.