Electrical Power Transmission Apparatus

When selecting an explosion-protected electrical apparatus for deployment in underground mines, the adage, “Better safe than sorry” should always apply. It is better to err on the side of caution by investing in a high-quality product that meets all considerations regarding explosion products. 

By Nick Barnes 

The observation that, increasingly, hard rock mining is going deep-level or ultra-deep has been mentioned in this publication several times. Operating in these environments comes with its unique challenges – one of them is increased safety risks or exposure to hazards.

Hence, the success of mining operations in this environment hinges on the effectiveness of measures to mitigate these risks. One of them involves choosing equipment or products used in those environments, especially when it comes to the risk of explosion.

Explosion protection

To improve safety, productivity and environmental sustainability at a deep level, electrifying mining operations has become a necessity. That’s why in the selection of electrical apparatus products used, explosion protection should be the main criterion. This is due to the risks that persist in those environments.

In this context, reference to electrical apparatus used for mining applications includes but is not isolated to the following: motors, starters, lamps, switches, junction boxes, fuses, cut-outs or any other appliance, equipment or fitting.

Concerning Explosion Protected Apparatus, South Africa’s Department of Mineral Resources and Energy defines it as the following: “Any apparatus used in a hazardous location and selected in accordance with the guidelines as defined in the South African National Standard SANS 1 01 08-2005.”  

Explosive atmospheres

The risk of explosion in underground mines should not be taken lightly.

Underground mines are explosive atmospheres with the presence of a flammable medium of gas, mist or vapour or dust. Most prevalent in underground mines is methane and air (based on Mining Business Africa’s engagement with mines).

Usually, when mixed with air, a flammable medium forms an explosive mixture. The flammable medium-to-air ratio determines the scale of the reaction – whether igniting and burning or an explosion. Nonetheless, these are risks that mining companies would not want to encounter at any cost.

Factors in selection 

No question informed decisions should be made in electrical-protected apparatus for deep-level mining.  For this reason, several factors have to be thoroughly analysed before selecting electrical transmission products. Mainly, these are external mechanical damage, environmental conditions, handling operations, explosive gases combined with dust, etc. Most importantly, ATEX Certification and IECEx Certification are highly recommended. 

No compromises 

The significance of using explosion-protected electrical transmission products should not be underestimated at any given time. The hazards that lurk in underground mines are high, even when, ostensibly, there is proof that they are not. This is given the unpredictability of conditions – circumstances can change in a split second. And so, no compromises should be made in product selection, even though there has never been a history of an explosion in a mine.

In general, it goes without saying that: It is better safe than sorry, err on the side of caution.