Safety while working on electrical installations

Electricity can kill, and injure, people. Too many electrical accidents at work are reported each year and far too many people are injured or even die of their injuries. There are simple precautions when working with or near live equipment that can be taken to significantly reduce the risk of electrical injury to the operator and others around him or her.

Carelessness and lack of concentration are some of the causes of many accidents that could have been avoided. Consequences are personnel accidents, operational downtime, destroyed equipment and environmental damage. To avoid accidents, it is mandatory to observe laws and safety regulations. Working on electrical systems and equipment should only be carried out by qualified personnel or by persons under qualified supervision.

In order to avoid accidents, five common safety rules have been formulated:

1. Disconnect completely
2. Secure against reconnection
3. Verify that no supply voltage is present
4. Carry out earthing and short-circuiting
5. Provide protection against adjacent live parts

DEHN has a range of products for personnel working in and at electrical systems and installations to meet the above requirements. The range of safety equipment includes voltage detectors, phase comparators, earthing and short-circuiting devices, equipment for working on overhead lines and equipment for cleaning under live conditions. In addition, a range of personal protective equipment (PPE) is available.

Independent from the operating state, all electrical systems and equipment must principally be regarded as energised until it is proven that there is no supply voltage present. Therefore, the voltage detectors used must provide reliable indication and the necessary electrical safety for the user.  This applies to both the test procedure and the test result. Both must be reliable.

The modular electronic contact type PHE III voltage detectors from DEHN are fully in accordance with the latest IEC standard and bear the mark of approval and are designed for safe testing of switchgear installations and overhead lines. They have a 3.3 kV to 132 kV/50 Hz nominal voltage range and can be used indoors and outdoors, as well as in wet weather conditions.

Currently, there is no standard available for non-contact-type voltage detectors and their use should be cautioned.

DEHN’s PHV phase comparators are two-pole devices that can provide safe and reliable operation while testing for in-phase conditions in three-phase electrical systems. They are suitable for rated voltages up to 36 kV/50 Hz and fully meet the requirements of IEC 61481 standards.

The DEHN range of portable earthing and short-circuiting devices is designed for use on overhead transmission and distribution power lines, indoor and outdoor substation busbars, electrified railway traction systems, transformer and switchgear terminals. The equipment ensures the safety of personnel while working on low-, medium- and high-voltage electrical systems in the event of accidental energisation.

DEHN has extended its portfolio of PPE to include an arc-fault-tested protective suit. In addition to safety helmets and protective gloves, the two-part protective suit protects workers from the thermal effects of an arc fault during work on electrical installations. To this end, the materials used provide maximum protection (IEC 61482-1-2, class 2) and good wearing comfort. This is ensured by breathable leather and neoprene materials which have already been used for the protective gloves.

In combination with the flame-retardant lining and the reflective strips, the protective suit provides protection to workers exposed to arc faults. The zip and hook-and-loop fasteners are also made from flame-retardant material. Besides the advantages described above, side arm and leg pockets with flaps complement its appearance. The suit is available in six sizes.

DEHN’s range of APG electric arc rated gloves are designed for maintenance and repair work at electrical installations. The APG protective gloves and material used have undergone extensive 7.0 kA/0.5 s arc fault testing in accordance with IEC 61482-1-2 (box test), and an EC-type certificate has been issued by an accredited certification body. The gloves have also been tested at the Kinectrics high current test laboratory in accordance with ASTM F 1959 requirements. They achieved an Arc Thermal Performance Value (ATPV) of 32.8 cal/cm² and a heat attenuation factor (HAF) of 93.4%.

In conclusion, it is imperative that before allowing work to start on electrical installations, those in control should identify the hazards present, the risks posed by the hazards and the control measures needed to reduce the risks so far as is reasonably practicable, to ensure safe and reliable operation.