Table of Contents
Design Features #
Principle and design
The safe operation of Increased Safety equipment depends on the prevention of any source of ignition (excessive surface temperatures, arcs or sparks) internally or externally.
Some of the special design features that are incorporated to achieve this include: –
- Ingress protection against solid objects and water – at least IP 54 for enclosures containing live parts (IP44 if all internal parts are insulated).
- Mechanically strong enclosure resistant to impact. Test conditions differ for equipment for use where risk of damage is HIGH, or LOW (‘X’ certificate).
- Terminals manufactured from high quality insulation material.
- Specified creepage and clearance distances incorporated in the design of terminals.
- Terminal locking devices to ensure conductors remain secure in service.
- Certified de-rating of terminals.
- Terminal population of enclosure limited by circuit design.
- Close excess current circuit protection.
