Risk Assessment for Temporary Electrical Installations and Portable Equipment on Construction Sites

How do you assess temporary electrics and portable electrical equipment on an Irish construction site?

Temporary electrical installations are a feature of almost every construction project, but they are often installed quickly, altered repeatedly and exposed to harsh conditions. Cables run across rough ground, distribution boards are moved as the site changes, tools are passed between contractors, and weather, water, dust and impact all take their toll. The result can be electric shock, burns, fire or damage to equipment.

A risk assessment for temporary electrics must do more than state “use 110V equipment”. It must consider the full system: incoming supply, distribution boards, transformers, RCD protection, cabling, portable tools, inspection arrangements, competent persons and the changing physical environment of the site.

The Legal Framework

Part 3 of the Safety, Health and Welfare at Work (General Application) Regulations 2007 covers electricity. Regulations 76 to 89 deal with the suitability of electrical equipment and installations, protection against electric shock, portable equipment, cables and connections, isolation, competence, and testing and inspection. General Application Regulations 2007

The Construction Regulations 2013 also require construction sites to be organised so that installations, machinery and equipment are properly used and maintained. The contractor who provides or controls an electrical installation must make sure it is suitable for the work and safe to use. The PSCS must coordinate the site arrangements so that different contractors do not create additional electrical risks.

Hazards the Risk Assessment Must Cover

Electric shock: Damaged cables, defective plugs, exposed conductors, poorly maintained tools and unsuitable equipment can expose workers to live parts. The assessment should identify the supply voltage, the protection measures, the expected environment and how defects will be reported and removed from service.

Water and damp conditions: Construction sites are frequently wet. Water increases the risk of shock and can damage equipment. The assessment must consider whether equipment has a suitable ingress-protection rating, whether connections are raised off the ground, and whether weatherproof distribution arrangements are needed.

Mechanical damage: Cables can be crushed by plant, cut by sharp edges, damaged by doors or buried under materials. Plan routes to avoid vehicle movements and pedestrian traffic. Where crossing a route cannot be avoided, protect cables with suitable ramps or overhead routing, not improvised timber covers.

Overloading and fire: Extension leads and distribution boards can be overloaded when multiple trades connect high-demand equipment. The assessment should identify the load requirements, suitable circuit protection, the need for separate circuits and the prohibition on daisy-chaining extension leads.

Work near live services: Temporary works may be carried out near existing electrical installations or underground cables. The assessment should include isolation procedures, service drawings, permits where required, and the competence of the person carrying out the work.

Portable tools: Grinders, drills, saws, heaters, task lighting and chargers are used throughout the site. Each must be suitable for construction use, visually inspected before use and subject to a planned test-and-inspection regime.

Core Control Measures

Use reduced voltage where appropriate: The use of 110V centre-tapped supplies is a common control for portable equipment on construction sites because it reduces the severity of electric shock. It is not a complete control on its own. The equipment, leads and transformer must still be maintained and protected from damage.

Provide residual current device protection: RCD protection provides an additional layer of protection by disconnecting the supply rapidly when leakage current is detected. The risk assessment should identify where RCDs are required, how they will be tested and who is responsible for the checks.

Use suitable distribution boards: Distribution boards should be weather resistant where exposed, securely mounted, labelled, lockable where necessary and protected from accidental damage. Cables should enter through suitable glands or protected openings. Open boards, improvised connections and trailing loose conductors should never be accepted.

Control cable routes: Plan cable routes before work starts and update them as the site layout changes. Keep cables away from water, sharp edges, vehicle routes, access routes and hot work. Avoid running cables through doorways unless they are properly protected.

Inspect and test: Visual checks should be carried out before use. Formal inspection and testing should be planned according to the type of equipment, its environment and the level of use. Keep clear records so defective equipment can be identified and removed from service.

Isolate before work: Work on electrical systems should be carried out dead wherever possible. Isolation must be secured against reconnection, verified by a competent person and controlled through a clear lock-off and tagging process.

Competence and Responsibilities

Regulation 88 requires persons to be competent to prevent danger where electrical work is being carried out. The risk assessment should identify who is authorised to install, alter, inspect and repair temporary electrics. General workers should not be permitted to modify distribution boards, replace protective devices or make improvised connections.

The site manager or electrical supervisor should maintain a simple register of distribution boards, transformers, cables and high-use portable equipment. Each item should have an identifiable inspection status, and workers should understand the process for reporting a defect. A damaged lead should be removed from service immediately, not wrapped in tape and returned to use.

Emergency Arrangements

The site emergency plan should include electric shock. Workers must know not to touch a person who may still be in contact with a live source. The supply should be isolated if it is safe to do so, emergency services should be called, and first aid should be given only when the rescuer is not at risk. Sites should ensure first aiders understand the emergency procedure and that access for emergency services is maintained.

Reviewing the Assessment

Temporary installations change as the project progresses. Review the risk assessment when the supply changes, a new area opens, major plant is connected, the site moves from structure to fit-out, or an incident or defect trend occurs. What was suitable during groundworks may not be suitable once several trades are working on multiple floors.

Conclusion

A good temporary-electrics risk assessment covers the system as well as the individual tool. It identifies the environment, routes, protection, inspection regime, competent persons and emergency arrangements. If your site needs a review of temporary electrical controls, RAMS or inspection records, Safety Check can provide practical construction-safety support.

Example Risk-Assessment Questions

Before energising a temporary installation, ask: What is the source of supply? Who installed it and is that person competent? Is the board protected from water and mechanical damage? Are all circuits identified? What is the expected electrical load? Where will cables run? Could vehicles, doors, sharp edges or water damage them? What RCD protection is in place? Who will inspect, test and maintain the system? How will defects be reported?

These questions should be repeated when the layout changes. A cable route that was safe during the shell-and-core stage may become unsafe when internal finishes, access routes and multiple trades are introduced. Treat temporary electrics as an active installation, not a once-off setup.

Portable Appliance Control

Workers should visually inspect portable tools before use. Look for damaged cases, cracked plugs, exposed wires, loose cable entries, missing guards and signs of overheating. Defective equipment must be taken out of service immediately, labelled and sent for repair or replacement. Do not allow workers to make temporary repairs using insulating tape or improvised parts.

Maintain a register of high-use tools and test equipment at intervals suited to the site conditions. Equipment used outdoors, in wet areas or by multiple contractors generally needs more frequent attention than equipment kept in a dry workshop. The register should identify the item, its location or owner, inspection date, outcome and next review date.

Coordination With Other Contractors

Temporary electrics are often shared across a site, which makes responsibilities easy to blur. The Construction Stage Safety and Health Plan should identify who controls the main supply, who is authorised to alter distribution boards and how subcontractors request additional supply. Agreeing these arrangements early prevents unsafe ad-hoc connections and overloaded circuits.

Electrical safety should also be covered in site inductions and toolbox talks. Every worker needs to know that damaged equipment, wet connections and exposed cables must be reported immediately, even if the defect appears minor.

Managing Electrical Changes Safely

Any alteration to a temporary electrical system should be requested through the site manager or nominated electrical person. This includes adding a distribution board, moving a supply, changing a protective device, connecting high-load equipment or extending cables into a new work area. The responsible person should assess the demand, protection, route and environmental conditions before the work is energised.

Keep electrical drawings and board schedules up to date. A simple, current diagram of the main supply, boards and work areas helps supervisors isolate circuits quickly in an emergency and prevents contractors connecting to unsuitable circuits. Label sockets and boards clearly so that workers know which supply they are using.

Site Inspection Prompts

During regular inspections, look for open distribution-board doors, missing blanking plates, cables in standing water, leads crossing vehicle routes, overloaded adaptors, damaged plugs, non-construction equipment in wet areas and untested RCDs. Record the finding, isolate unsafe equipment and check that corrective action has actually been completed.

Temporary electrics are safest when the inspection system is visible and easy to use. Workers should be able to report a defect quickly, and supervisors should have authority to remove unsafe equipment without waiting for a lengthy approval process.