Powering devices and equipment

Very strict constraints for batteries, their containers and battery-powered devices in Ex areas

By Claire Marchand

Batteries come in all forms and shapes and are probably the most common and widespread means of energy storage. From the AA or AAA type you buy at your local supermarket to the highly-sophisticated new generation of batteries used in smart portable devices, there are millions of products on offer. Not to forget electric vehicles (EVs). To increase their capacity and minimize their size, the batteries that power them are the focus of intense research and development throughout the world.

Ex-proof electric forklift Explosion-proof electric forklifts meet the highest safety requirements to operate in hazardous environments (Photo: Miretti)

Extensive use

Whether off-the-shelf or specially-designed cells, primary or secondary (rechargeable) batteries are all built on the same model: one or more electrochemical cells that convert stored chemical energy into electrical energy. 

Lead/acid batteries or alkaline (nickel-cadmium, nickel-metal hydride or lithium ion) rechargeable batteries are used in all kinds of small devices, such as computers, smartphones, tablets and cameras. Their large-capacity counterparts are commonly used in transport (EVs, industrial EVs, buses and trucks) and in UPS (uninterruptible power supply) systems. 

Ex environments multiply the risks

These same batteries are used extensively by the explosive (Ex) industry sector. The people working in flammable and potentially explosive conditions depend on battery-powered portable and fixed equipment such as walkie-talkies, lamps, gas detectors and air-monitoring devices. They may also operate electric forklifts and other industrial EVs within large facilities, plants and mines. 

IEC and IECEx: mitigating risks

While the recharging of batteries, large and small, can be hazardous in itself – hydrogen and oxygen are usually produced inside the battery when charging – the risks are much higher in Ex environments. 

This is why, in some cases, the batteries themselves, although very similar to their off-the-shelf counterparts, or the battery pack/box/ container have to be designed and build in compliance with the very strict requirements enunciated in standards and specifications, most notably in IEC International Standards developed by IEC Technical Committee (TC) 31: Equipment for explosive atmospheres. This is valid for small-capacity cells as well as for traction batteries (used in EVs). 

Battery-operated devices are submitted to the same constraints. Their design and manufacture must be able to withstand the harshest and most extreme environmental conditions. They have to be well insulated and explosion-proof. 

Certification needed

Designing and building batteries and containers in compliance with IEC International Standards is not enough. To ensure that any piece of equipment meets the required criteria, it has to be tested and certified. Products associated with a certificate of conformity can be used safely in hazardous environments. 

IECEx, the IEC System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres, is the only truly international Conformity Assessment (CA) System that provides testing and certification for all Ex equipment and installations as well as certifies the skills and competence of individuals working in hazardous areas. 

Increased level of security

Manufacturers who rely on IECEx for the testing and certifying of their equipment, who have their staff go through the steps necessary to obtain a Certificate of Personnel Competence, have that additional level of security that makes a real difference. They know that they operate in the best possible conditions and minimize the risks inherent to Ex sector. 

United Nations endorsement

With its three Schemes, IECEx covers all aspects of conformity assessment in the Ex field. In addition to equipment and personnel, the System also provides testing and certification for service facilities that repair and overhaul Ex equipment. Its global scope has been reinforced by the endorsement it received from the United Nations through the UN Economic Commission for Europe (UNECE) as the internationally-recognized certification system for promoting the safety of equipment, services and personnel associated with devices, systems and installations used in explosive areas. 

Access to certificates anytime, anywhere

IECEx has developed mobile applications for iOS, Android tablets and smartphones, that can be found at the Apple App Store and Google Play. They install simplified versions of the main IECEx online Certificate System covering the three Schemes and allow the user to synchronize the Ex mobile apps with the IECEx online Certificate System, as required. The offline mode provides advanced search capability and certificate abstracts (simplified details), while the online version gives the full details of the Certificates.

For more information on IECEx: www.iecex.com

Gallery
Ex-proof electric forklift Explosion-proof electric forklifts meet the highest safety requirements to operate in hazardous environments (Photo: Miretti)
Ex-proof flashlight Battery-powered explosion-proof LED flashlight (Photo: Larson)
Intrinsically-safe indicator for Ex environments Intrinsically safe indicator for explosive environment with Ex-proof battery pack (Photo: Optima Scale)