Electricity and Control March 2016

HAZARDOUS AREAS + SAFETY

• Unexpected machine start-ups can cause severe injury to operators and extensive damage to equipment. • LOTO systems ensure that dangerous machines are properly shut off and not restarted before completion of maintenance and servicing. • A good LOTO system consists of clearly labelled energy sources, easy-to-follow procedures, and lock-out tools that ensure quick service and maintenance activities.

take note

The equipment should be turned off at its main source, which is either a circuit breaker, mains connection, air or hydraulic line, for example. It is important to bear in mind that there may be more than one shutdown point, and all of these should be turned off. The next step is to place a special lockout device on each source of energy, and to attach a tag to each lockout device so that employees are aware of the situation. Equipment may contain stored or potential energy that could cause harm – this should be released or blocked. After following these procedures, test for zero energy by trying to start the equip- ment. LOTO doesn’t end when repair work is complete, and inspec- tions must be done before starting the equipment up again. The site should be inspected for tools and parts that may be lying around on the floor or machinery, and equipment controls must be in the off or neutral positions, before the locks and tags are removed by authorised personnel only. Locks and tags should be returned to designated areas and employees should be notified that the equipment is being powered up again. Group Lockout When two or more workers are working on different parts of a larger overall system, the locked-out device is first secured with a folding scissors clamp that has many pad- lock holes capable of holding it closed. Each worker applies their own padlock to the clamp. The locked-out device cannot be activated until all workers have signed off on their portion of the project and removed their padlock from the clamp. A lock selected by colour, shape or size is used to designate a standard safety device, locking and securing hazardous energy. No two keys or locks should ever be the same. A person's lock and tag must not be removed by anyone other than the individual who installed the lock and tag unless removal is ac- complished under the direction of the employer. Trained personnel should always manage the LOTO system. For instance, if a steam valve automatically gets turned on, it might burn the workers who are repairing a downstream connection in the piping. Another scenario is the sudden release of a jammed conveyor system, which can result in the crushing of workers, if not properly managed. It is the responsibility of the employer to develop and implement an energy control procedure that provides authorised and affected employees with the same level of protection as a personal lock-out or tag-out device. A good LOTO system consists not only of clearly labelled energy sources and easy-to-follow procedures, but also quality and accessible lock-out tools to ensure smooth and quick maintenance and servicing activities.

Types of padlocks Lock-out padlocks are available in nylon, aluminium, steel and brass body options. Nylon body padlocks are best-suited to elec- trical applications, due to the non-conductive properties of the material. Temperature and corrosion-resistant aluminium body padlocks are ideal for high-temperature outdoor applications up to 580°C. Owing to their strong physical resistance characteristics, steel body padlocks are designed for severe physical environments, while spark-resistant brass body padlocks are ideal for use in flam- mable applications. The range of padlocks described feature shackle diameters ranging from 4,7 mm to 7 mm, and have shackle heights ranging from 20 mm to 75 mm.

Hayley Arnesen has had over 16 years of experience in the safety industry. Her experience has been diverse spanning many industries and functions. She currently works for North Safety Products Africa as Exports Manager. Enquiries: Tel. +27(0)11 974 7062 or email harnesen@ northsafety.co.za

Electricity+Control March ‘16

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