Baptism of fire

New Technical Report from IEC SC 121A

By Catherine Bischofberger

Health and safety have always been key drivers behind the publication of IEC Standards. Electricity can be dangerous and electrotechnical equipment and systems can cause different types of hazards if not used according to a set of pre-determined safety rules. A new Technical Report (TR) published by IEC Subcommittee (SC) 121A lists fire risk reduction measures as applied to low voltage switchgear and controlgear.

short circuit Sparks generated by short circuits can cause fires and explosions

The first risk that comes to mind when dealing with anything electric is electric shock. However electric sparks, which can result from something as mundane as a short circuit, can also start a fire or even an explosion, as some of us may have found out to our detriment.

Fire hazards are one of the main risks when dealing with faulty pieces of electrical equipment or installations. IEC product Standards for electrical equipment offer risk reduction measures and aim to minimize residual risk without compromizing product safety and function.

One such family of Standards is the IEC 60947 series on low voltage switchgear and controlgear. Published by IEC Technical Committee (TC) 121: Switchgear and controlgear and their assemblies for low voltage, the series sets out functional safety guidelines for equipment ranging from switches to rotating electrical machines.

IEC TC 121 is divided into two Subcommittees, SC 121A, dealing with switchgear and controlgear products and SC 121B, dealing more specifically with assembly of the equipment.

SC 121A has recently published a Technical Report which establishes risk reduction measures for low voltage switchgear and controlgear. An IEC TR differs from an IEC Standard, by providing, for instance, the latest research into cutting-edge advances in technology.

IEC/TR 63054, Low voltage switchgear and controlgear - Fire risk analysis and risk reduction measures, describes the risk reduction measures in the IEC 60947 relevant publications. These include measures to be taken to avoid ignition, for instance when short circuits occur. One example is the requirement to select appropriate insulating materials for the insulating components.

It also mentions the latest research into electrical fires undertaken by Dr Vytenis Babrauskas, one of the world’s leading experts on fire ignition. While this information applies specifically to low voltage switchgear, the report stresses that “other product committees may find this information useful”.

Gallery
short circuit Sparks generated by short circuits can cause fires and explosions
electric explosion Electric explosions can be spectacular (Photo: ECmag.com)
control gear enclosure The new TR published by IEC SC 121A lists fire risk reduction measures as applied to low voltage switchgear and controlgear