WHAT IS EXPLOSION PROOF (EX-PROOF)?
- Sep 11, 2019-
There are six types of area classification guide to classify explosion-proof environment:
Type of protection
New Number (IEC)
IEC stands for International Electrotechnical Commission, a non-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies – collectively known as "electrotechnology".
Place of use
Mines susceptible to firedamp
II B + H2
Equipment protection level (gas/dust)
An area in which the mixture of explosive gas is constantly present (ex. the inside of a fuel tank).
An area in which a mixture of explosive gas may be present during the normal operation of the plant.
An area in which the mixture of explosive gas is not normally present, but is only present for brief periods of time.
An area in which the mixture of explosive powder is constantly present (ex. the inside of fuel tank).
An area in which a mixture of explosive powder may be present during the normal operation of the plant.
An area in which the mixture of explosive powder is not normally present, but is only present for brief periods of time.
Ingress protection (IP)
First figure indicates protection against dangerous access and solid foreign objects
Second figure indicates protection against water penetration
Protected against solid objects 50 mm Ø or more
Protected against vertically falling water drops
Protected against solid objects 12.5 mm Ø or more
Protected against vertically falling drops water enclosure tilted up to 15º
Protected against solid objects 2.5 mm Ø or more
Protected against spraying water up to 60º from vertical
Protected against solid objects 1 mm Ø or more
Protected against splashing water from any direction
Protected against jets of water from any direction
Protected against powerful jets of water from any direction
Protected against immersion
Protected against continuous immersion
The minimum requirement for Explosion-Proof protection is IP54.
Supermec mostly caters to Ex “d” and Ex “e” types of protection. The table below shows the advantages and disadvantages of the two:
1. capable of withholding a possible internal explosion and prevent its transmission to the atmosphere outside the housing
2. higher class of protection
3. easily available and cheaper components
1. maintenance more complicated ( e.g. difficult to change fluorescent tubes)
2. piped plant (where requested) complicated
1. easy installation
2. pleasant appearance
3. safety cut-off switch
1. high cost of spare parts (components must be Ex type)
2. frequent and costly maintenance (e.g. seal)