In PART 1 of Explosive Environments, we introduced you to explosive environments in the workplace. We gave an overview on how to classify explosive areas according to the necessary standards, and explained the compliance standards your company should adhere to, for specific areas, at all times. Furthermore, we identify what to look for when installing and operating electrical equipment in an explosive area.
In PART 2, we’ll be covering temperature classification, IP ratings and nameplates. We end off with a summary of some explosions that took place at South African facilities.
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Temperature Classification
It is required that the temperature class of selected equipment may not exceed the ignition temperature of any gas that is present in the atmosphere. The table below indicates the temperature class and the corresponding ratings.
The ambient temperature rating of the equipment must cover the full range of possible temperatures in the areas located. If the ambient temperature is not specified on the equipment, then the equipment must be operated within the ambient range of –20°to +40°C.
Ingress Protection Ratings
It is vital that the ingress protection of equipment be suitable at all points where it is used. This is done to prevent any foreign objects or flammable substances from entering the equipment’s enclosure. The IP rating is used to indicate the resistance offered by the fixture to the penetration of solids and liquids. The IP rating consists of a two-digit number. The first digit is used to identify the degree of protection, against the ingress of solids, whilst the second digit identifies the degree of protection against the ingress of liquids.
Click here to DOWNLOAD our IP Rating Chart.
Information Given on an Equipment’s Nameplate
Most equipment nameplates will have some common items of information. Many of these are self-explanatory, and include:
• Manufacturer
• Manufacturerʼs address
• Model number
• Serial number
• Certification mark(s)
The manufacturers literature may help decipher the coding used for particular equipment. Example of a flameproof motor nameplate cipher, below.
Explosions that Occurred in South African Plants and Facilities
- SAPREF Refinery: 21 April 2004
A power failure caused a fire in the distillation unit with huge clouds of thick black smoke over South Durban. - Engen Refinery: 16 April 2006
A large explosion shook Wentworth and Merebank residents which left one worker injured. The worker was burnt due to asphalt falling on his arms when the fire was being extinguished. - Engen Refinery: 11 October 2006
Residents from surrounding areas reported a ball of black smoke from the stacks for an hour. This was caused by an electrical shutdown prompting fuel gas to be sent into the flares. - SAPREF Refinery: 28 October 2006
A fire occurred in the diesel de-sulphurising unit. The fire lasted for 3-hours resulting in smoke throughout the South of Durban, which affected residents. - Engen Refinery: 19 November 2007
A storage tank that consisted of 7 million litres of petrol burned to the ground for 58 hours. - KZN Oil: 26th March 2015
A fire erupted across Clairwood Racecourse that resulted in people and workers being evacuated. - Engen Refinery: 4 December 2020
Several residential apartments nearby were burnt as a result of the refinery explosion, and a local child suffered from face and body burns.
Concerned about the equipment installed in explosive atmospheres at your facility? CHAT to us now!
SHOP Explosion Proof Lighting, Plugs and Sockets on the Magnet Store.
Sources:
https://www.ee.co.za/article/explosive-environments-fundamentals-area-classification-2.html
https://www.raytecled.com/blog/identifying-zone-0-zone-1-and-zone-2-hazardous-areas/
https://www.ee.co.za/wp-content/uploads/legacy/Hazardous%20area%20classifications%20(SANS10108).pdf
https://www.ee.co.za/article/138434.html
https://pmg.org.za/committee-meeting/31716/