HSENI Safety Alert - Metal battery isolator switches

Introduction

HSENI have been informed of a serious technical fault with battery isolator switches which are used widely across extractive industry manufacturers in Northern Ireland and other industries to prevent re-energisation of a machine once locked out.

The HSE in Great Britain has discovered that it is possible to re-energise a machine with the isolator lock-off system correctly in place using metal battery isolator switches. Some metal battery isolator switches are therefore not suitable and sufficient to controls and manage the risk.

Issue

On certain metal battery isolator switches it has been discovered that it is possible to re-energise the equipment with the isolator lock-off system correctly in place.

This safety alert has information and advice on what to do if you supply, install, use, inspect, service, maintain or examine machines for use at work with metal battery isolator switches present.

Outline of the Problem

During Lock Out, Tag Out, Try Out (LOTOTO) training course in GB, it was found that an item of mobile crushing and screening plant had a defective metal battery isolator switch. The machine was isolated using the correct isolator switch and an industry standard hasp was attached along with a padlock.

During the ‘try-out’ phase of the LOTOTO procedure it was discovered that the metal battery isolator switch could easily be defeated by moving it with the hasp still attached. This re-energised the machine, allowing the machine to be started and run.

This is a dangerous situation.

Action Required

You should immediately check the necessary control measures are in place for all machines in use, or available for use, at a workplace.

In order to determine if the correct control measures are in place, undertake the following instructions:

• lock off the metal battery isolator switch, turn it as far as it will easily turn and hold it in that position
• have another person check if the machine re-energises - if it has, do not rely on the isolator lock-off

If the above occurs, or any defects are noted with battery isolator switches, you should make contact immediately with the manufacturer of the machine.

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