6.3 Important issues when working live
6.3.1 Documentation
6.3.2 Conductive materials
6.3.3 Work position
6.3.4 Safety observer
6.3.5 Emergency planning
6.3.6 Safety barriers and signs
6.3.7 Personal protective equipment
6.3.1 Documentation
The occasions that live work is permitted is restricted by Regulation. The Regulation also has a number of requirements, eg a safe system of work must exist before working live. A safe system of live work should be developed with people who:
- Are representative of the electrical workers; and
- Have skills and knowledge in the area of work.
Control measures chosen for live work should not rely solely on items such as flame retardant or flame resistant clothing and personal protective equipment (PPE). Appropriate control measures can include:
- Isolating as many of the sources of electric potential as possible. This may involve working live, though surrounding parts need not be live;
- Reducing the fault level, eg performing the work out of hours when the supply can be fed from only one transformer or a generator;
- Using a safety switch (residual current device), eg testing an appliance; and
- In situations where uninterruptible power supplies, backup generators, auto-reclosing, or auto change over systems are installed, these facilities should be disabled.
6.3.2 Conductive materials
Workers can be exposed to the hazards of electric shock, arcing and explosion without making direct contact with exposed live parts. Other materials can provide current paths for the electric shock, fault current, or both.
All materials should be regarded as conductive, unless proved otherwise. Gases and liquids should be regarded as conductive materials.
Particular care should be taken when exposed live parts are near earthed situations. The electric shock path to earth can be via conductive materials, such as concrete, timber with a high moisture content or water.
Metallic personal items, such as watches and watchbands, should not be worn when working near exposed live parts. Objects of this kind can result in electric shocks. In addition, burns sustained near these items can be worse because the objects retain heat and provide contact points for current to flow.
Examples of other metal objects that should not be worn when performing electrical work include:
- Neck chains;
- Rings;
- Bracelets;
- Earrings, body piercing; and
- Metal spectacle frames.
6.3.3 Work position
To prevent electric shock, you should work from a position where any contact with electricity would require a deliberate movement to touch energised parts or create a current path. Adequate working clearance to allow safe access and egress from the work position, in the case of an emergency, should be maintained.
Examples:
- Choice of body position should be such that if you made an involuntary action such as sneezing, you would not touch exposed live parts, eg fault finding on a Programmable Logic Controller (PLC) whose inputs are next to live exposed parts;
- When working in an awkward position – such as testing components towards the rear of a washing machine via the front panel, eg in a laundromat – the work system, including body position, should be such that no electric shock path can be created; and
- Per forming phase sequencing or rotation testing on overhead mains or at an underground pillar, the work system, including body position, should be such that no electric shock path can be created.
If a circuit breaker has the facility to be remotely operated, the preferred work position should be communicated to workers. For example, is operating a circuit breaker by standing at the unit acceptable, or, is it preferred to use remote control facilities?
6.3.4 Safety observer (electrical)
A safety observer (electrical) must be used when per forming live electrical work unless the work involves testing electrical equipment.
Where the work has been assessed as high risk, a safety observer (electrical) should be used as one form of control measure unless the safe system of work specifically addresses the likelihood of inadvertent contact with exposed live parts through alternative measures.
Examples of high risk work include:
- Fault finding at a switchboard that has a high prospective fault current level;
- Installing and replacing components at a switchboard;
- Where the worker is in the ‘safety observer zone’, ie near the exclusion zone for exposed live parts; and
- Performing complex fault finding.
If a safety observer (electrical) is used as part of a risk management strategy, the following should apply:
- The safety observer's (electrical) role should be clearly communicated and understood. The role is to warn the worker or workers of danger as well as to perform rescue and resuscitation, as required;
- A safety observer (electrical) should have the authority to stop the work before the risks become too high;
- The safety observer (electrical) should not carry out any other work or function that compromises their role as a safety observer;
- The safety observer (electrical) should be able to communicate effectively with the worker or workers. Specialist equipment may be necessary in situations where there is a barrier to communication;
- The safety observer (electrical) should not have to observe more than one task at a time;
- A safety observer (electrical) should not be situated in the work basket of the elevating work platform16; and
- To meet an electrical safety obligation, a safety observer (electrical) should not be regarded as the sole control measure to ensure electrical safety.
6.3.5 Emergency planning
If a person sustains an injury due to electrical hazards, prompt and timely action can significantly reduce the injury’s severity. Quick action may even save a life.
After an electrical incident, there is still a risk of injury because of the three common electrical hazards (refer to section 4.4). It is crucial that the response be appropriate to electrical risk. For example, in a live low voltage situation, rescue may be acceptable. However, should a rescue require either the victim, the rescuer, or both to intrude into safe approach distances for exposed live high voltage, isolation and proving de-energised should be performed.
In an effective safe system of work, workers should be competent at reacting to electrical incidents to prevent injury or further injury. Emergency actions should be taken that suit the work being done. Processes and procedures that should be considered include:
- Response to high voltage incidents and injuries. This should include forms of isolation and access; and
- Response to low voltage incidents and injuries. These should include rescue procedures such as:
- Low voltage pole rescue;
- Low voltage switchboard rescue;
- Confined space rescue eg rescue from low voltage cable pits;
- Rescue and escape from an EWP;
- Cardiopulmonary resuscitation; and
- First aid including treatment of burns.
6.3.6 Safety barriers and signs
Safety barriers and signs can be used to control risks such as those mentioned in section B.1. Hazards such as electric shock associated with working near exposed live parts can also be controlled using barriers and signs.
Barriers and signs may be designed, erected or installed to:
- Protect the electrical worker from making contact with live parts;
- Ensure that access to and egress from the work location of live work allows for clear, unobstructed passage;
- Warn others and direct them away from live parts;
- Be temporary or permanent; and
- Clearly designate the safe work area by defining the approach path to a piece of equipment.
6.3.7 Personal Protective Equipment (PPE)
Refer to section 4 for the hierarchy of risk controls. The hierarchy lists personal protective equipment (PPE) as the last option or least preferred option.
PPE should be fit for purpose. The correct application, use, maintenance and testing of PPE should be explained to users.
Examples of PPE applications include:
- Reducing risks rather than compounding risks eg if an explosion occurs at thigh height that causes the energy vents upwards. In this situation, a dust coat or an incorrectly fitted face shield could trap the explosion rather than protect someone from it; and
- Prevention or reduction of the effects of electric shock and burns may be controlled by:
- Using clothing that covers the arms, legs and body. The clothing should have flame resistant or retardant properties eg cotton or wool, and contain no metallic threads or exposed conductive material eg zip or rivets in jeans;
- Using non conductive footwear, such as steel toe capped boots or shoes manufactured to a suitable standard; and
- Using insulating gloves.
16 The term "elevating work platform" is defined in Appendix A.
Last updated July 16, 2009
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