Prevention of unexpected start-up standard EN 1037+A1

the requirements for unexpected start up are defined in the standard EN 1037+A1 (june 2008) 

this standard is a B1 type according to EN 414

The contentof the standard is


1 Scope
2 Normative references
3 Definitions
4 General
4.1 Isolation and energy dissipation
4.2 Other means to prevent unexpected [unintended] start-up
5 Devices for isolation and energy dissipation
5.1 Devices for isolation from power supplies
5.2 Locking [securing] devices
5.3 Devices for stored energy dissipation or restraint [containment]
5.4 Verification 
6 Measures – other than isolation and energy dissipation – intended to prevent unexpected start-up
6.1 Design strategy
6.2 Measures intended to prevent accidental generation of start commands
6.3 Measures intended to prevent accidental start commands resulting in an unexpected start-up.
6.4 Automatic monitoring of the category 2 stopped condition

Annex A (informative) Examples of tasks which can require the presence of persons in danger
Annex B (informative) Signalling, warning
Annex ZA (informative) !Relationship between this European Standard and the Essential Requirements of EU Directive 98/37/EC
Annex ZB (informative) !Relationship between this European Standard and the Essential Requirements of EU Directive 2006/42/EC

The following definitions are important  for this standard

start-up (machine start-up)
change from rest to motion of a machine or of one of its parts
NOTE The definition includes functions other than motion, e.g. switch-on of a laser beam

unexpected [unintended] start-up

  • any start-up caused by:
  • a start command which is the result of a failure in, or an external influence on, the control system;
  • a start command generated by inopportune action on a start control or other parts of the machine, as e.g. a sensor or a power control element;
  • restoration of the power supply after an interruption;
  • external/internal influences (gravity, wind, self-ignition in internal combustion engines…) on parts of the machine;

NOTE Automatic machine start-up during normal operation is not unintended, but can be considered to be unexpected from the point of view of the operator. Prevention of accidents in this case involves the use of safeguarding measures (see clause 4 of EN 292-2:1991)