Risk reduction in the case of a fault [t-head1-first]

A fault in the electrical equipment must not result in a dangerous situation or in damage. Suitable measures must be taken to prevent danger from arising.

The IEC/EN 60204 -1 specifies a range of measures which can be taken to reduce danger in the event of a fault.

Use of proven circuit engineering and components [t-head3]

All switching functions on the non-earthed side

Use of break devices with positively opening contacts (not to be confused with interlocked opposing contacts)

Shut-down by de-excitation (fail-safe in the event of wire breakage)

Circuit engineering measures which make undesirable operational states in the event of a fault unlikely (in this instance, simultaneous interruption via contactor and position switch)

Switching of all live conductors to the device to be controlled

Chassis earth connection of the control circuit for operational purposes (not used as a protective measure)

Redundancy [t-head3]

This means the existence of an additional device or system which takes over the function in the event of a fault.