A crew is coring a slab on a council job. The core drill is run from a generator on the back of a ute, through two extension leads joined in a puddle, with a third lead feeding a work light. The drill has a tag from eighteen months ago. Nobody has thought about any of this because nobody has ever been hurt doing it.

Every element of that arrangement is a known cause of electrocution: a damaged lead, a wet connection, a generator whose protection nobody verified, and equipment outside its inspection interval. It is also entirely typical of small civil sites, which is why this is worth a guide of its own.

This is about the electricity you bring. Overhead assets are covered in our guide to working near overhead powerlines, buried cables in underground services and utility strikes, and the construction of electrical assets as a work type in street lighting, traffic signals and electrical civil works.

Three electrical risks, and only one of them is yours to bring

Risk	Whose asset	Where it is covered
Contact with overhead lines	The network operator’s	Working near overhead powerlines
Striking a buried cable	The network operator’s or a private owner’s	Underground services and utility strikes
Your own temporary supply and equipment	Yours	This guide

The first two produce the dramatic incidents and get most of the attention. The third produces a steady trickle of shocks, burns and near misses that are rarely reported, and it is the only one where every control is entirely within your hands.

Why a construction site is treated differently

Electrical rules for construction and demolition sites are stricter than for an office or a workshop, and the reasons are physical rather than bureaucratic.

• The environment is hostile. Water, mud, dust, heat, UV and abrasion all degrade insulation faster than any indoor setting.
• Equipment is mobile and handled roughly. Leads are dragged, driven over, pinched in doors and pulled from sockets by the cord.
• Earth contact is excellent. People stand on wet ground, in excavations and on steel, which is the condition in which a shock becomes a fatality.
• The installation is temporary and changes constantly, often assembled by whoever needed power that morning.
• Several businesses share the same supply, so nobody owns the whole arrangement.

Those conditions are why work health and safety regulations, supported by the Australian/New Zealand standard for electrical installations on construction and demolition sites, impose residual current protection on portable equipment, shorter inspection intervals and specific requirements for temporary switchboards. The standard is the document to work from; its detail is not reproduced here and should be taken from the current edition and the regulation in your jurisdiction.

Where the power comes from

Four arrangements cover nearly all civil work, and each carries a different obligation.

Supply	Typical use	Watch for
Portable generator	Most small civil sites, remote work, maintenance crews	Earthing arrangement and whether protection actually works — see §07
Temporary builder’s supply	Subdivisions, longer compounds	Installed and connected by a licensed electrician; needs inspection and a compliance record
Connection to an existing installation	Works at a depot, school, plant or operating facility	The asset owner’s permit and isolation process applies; their RCD protection may not extend to your gear
Battery and inverter	Lighting, small tools, site sheds	Fewer shock risks, but inverter output still needs protection and charging introduces fire risk

The arrangement most often got wrong is the third. Plugging into the client’s building supply does not make the client responsible for your equipment, and a socket in an operating facility may have no residual current protection at all. Confirm what protection exists before you rely on it, and bring your own portable protection if it does not.

RCDs: the control that does the work

A residual current device detects current leaking to earth — typically through a person — and disconnects fast enough to prevent most electrocutions. On a construction site it is not an optional extra; portable and hand-held equipment is required to be protected by one.

• Protection must cover the equipment, not just the board. A lead plugged in upstream of the RCD is unprotected, and on a site with several boards and long runs that is easy to do by accident.
• Portable RCDs are legitimate and useful where you are working from someone else’s socket, but they must be in good order and tested like any other item.
• Push-button test, regularly. The test button verifies the mechanism and takes seconds. Many sites never do it.
• Periodic operating-time testing is a separate, instrumented test, done at set intervals by a competent person, and recorded.
• Nuisance tripping is information, not an inconvenience. An RCD that keeps tripping is usually detecting a real fault — moisture in a lead, a failing tool — and the correct response is to find it.
• Never bypass one. Plugging around a tripping RCD to get the job finished is the decision that appears in fatality reports.

Note the limit of the control: an RCD protects against earth leakage. It does not protect against contact between active and neutral, and it does nothing about arc flash or burns. It is the most important control, not the only one.

Leads, the most damaged item on any site

Extension leads cause more electrical incidents on construction sites than any other item, because they take the most punishment and get the least attention.

• Use heavy-duty construction-rated leads, not domestic ones. The difference is insulation and conductor size, and it is visible once you know to look.
• Keep them off the ground where you can — on stands, hooks or catenaries. A lead on the ground will be driven over, buried, or left in water.
• Never run a lead through a doorway, under a plate or across a haul road unprotected. If it must cross a trafficked area, protect it in a ramp or duct.
• Do not join leads to make length. Every joint is a failure point, and joints in wet conditions are the classic fatality setup. Use one lead of the right length.
• No taped repairs. A damaged lead is replaced or repaired by a competent person — insulation tape over a cut is not a repair, and it is the most common finding in any site audit.
• Unplug by the plug. Pulling by the cord is what loosens terminations inside the plug, which is where many faults begin.
• Uncoil fully in use. A coiled lead under load heats, and a reel left wound can melt its own insulation.
• Check before every use. A visual check for cuts, crushing, exposed conductors and loose plugs takes seconds and catches most of it.

Inspection, testing and tagging

Electrical equipment on a construction site must be inspected and tested at intervals, and tagged to show it. The interval for construction work is substantially shorter than for ordinary workplaces, which is the point small contractors most often miss.

• Take the interval from the regulation and the standard, not from the last tagger who visited. It is shorter for construction and demolition work than for general workplaces, and it differs for different equipment types.
• Testing is done by a competent person. That is a defined competency; it is not automatically an electrician, and it is not automatically the oldest person in the crew either.
• The tag is the visible part; the register is the evidence. A tag can fall off, be swapped between items or be illegible. A register of items, test dates and results is what an auditor and an investigator will ask for.
• Out of date means out of service. Equipment past its interval is quarantined, not used until someone gets around to it.
• New equipment is not exempt. It generally needs to be recorded and brought into the regime, even where it does not need immediate testing.
• Hired equipment arrives with its own status. Check the tag on delivery rather than assuming the hire company has it covered — and note that under a plant hire agreement the maintenance obligation may well have shifted to you.

The practical system for a civil SME is a register by item with a next-due date, reviewed monthly, and a visible quarantine point — a bin or a hook — where failed or expired equipment goes. The competency and record-keeping discipline is the same one described in our guide to operator competency, high risk work licences and VOC.

Generators, and the mistakes that make them dangerous

Most civil work outside a compound runs on a portable generator, and generators are where the assumptions hide.

• Not every generator provides the protection you assume. The earthing arrangement of a portable generator determines whether a standard RCD will even operate. This is a genuinely technical question and the right answer comes from a licensed electrician for your specific unit, not from the manual’s safety page.
• Do not back-feed an installation. Connecting a generator into a building or a temporary supply without proper changeover equipment can energise conductors that someone else believes are dead.
• Exhaust is a separate killer. Carbon monoxide from a generator sited near an excavation, a pit, a chamber or a shed has caused deaths. Site it well clear and downwind of anywhere people are — and never where it can feed a confined space or its ventilation intake.
• Refuelling is a fire risk. Hot engine, spilled fuel, and often a jerry can in the sun. Shut down, allow cooling, and handle fuel properly — see bulk fuel storage and dangerous goods for the storage side.
• Protect it from weather and traffic. A generator in the open on a wet site is an electrical hazard; a generator beside a haul road is a collision waiting to happen.
• Include it in the inspection regime. Generators are routinely the one item on site with no tag and no record.

Water, mud and the wet-weather problem

Wet conditions turn a tolerable arrangement into a dangerous one, and civil sites are wet by nature — rain, dewatering, dust suppression, water carts and concrete washout all contribute.

• Keep connections out of water. Plugs and sockets lying in a puddle are the single most common unsafe condition on a wet site.
• Use equipment rated for the conditions, and remember that a rating protects the item, not the connection you made to it.
• Elevate boards and leads before the rain arrives, not after.
• Stop work in storms. Operating electrical equipment outdoors in a thunderstorm is a stop-work trigger, and it belongs in the weather provisions covered in our guide to heat, UV and extreme weather.
• Treat pumps with particular care. Electric dewatering pumps sit in water by design, which makes their leads, connections and protection critical — see dewatering and groundwater.
• Dry out before re-energising. Equipment that has been submerged or soaked is inspected before it goes back into service, not plugged in to see if it still works.

Tools, plant and battery kit

Beyond the supply itself, three equipment questions come up repeatedly.

• Double-insulated tools still need inspection. The construction of the tool reduces one risk; it does not remove the lead, the plug or the need for a record.
• Plant has electrical systems too. Welders, compressors, lighting towers, traffic signal trailers and site sheds all carry electrical risk, and they are frequently left out of the register because they are thought of as plant rather than as electrical equipment.
• Battery tools remove the shock risk and add a fire one. Lithium battery charging is a genuine site fire cause: charge in a designated place, not in a shed full of fuel or on a vehicle seat, and remove damaged or swollen batteries from service immediately.

The maintenance and record side of plant generally is covered in our guide to plant maintenance, availability and the workshop; the point here is simply that the electrical items on plant belong in the electrical register as well.

Who is allowed to do what

The boundary between what a civil crew may do and what requires a licensed electrician is narrower than many contractors assume, and getting it wrong is both a safety and a licensing problem.

Task	Generally
Visual inspection of leads and tools before use	Any worker, and expected of them
Push-button testing an RCD	Any competent worker
Routine inspection, testing and tagging	A competent person as defined by the regulation — training required, not necessarily an electrician
Repairing a lead, plug or tool	Licensed electrical work in most cases
Installing or altering a temporary supply or switchboard	Licensed electrician
Connecting a generator to an installation	Licensed electrician, with proper changeover
Isolating a client’s installation to work on it	The asset owner’s process, by their authorised person

The licensing regimes differ between states and territories, and electrical work is one of the most consistently licensed activities in the country — see our guide to contractor licensing by state. Where you sublet electrical work, verifying the licence is part of engaging the subcontractor, not an afterthought — see engaging and managing subcontractors.

Other people’s power, and other people on yours

Shared supply is where accountability dissolves, and on a civil site it is the norm rather than the exception.

• Decide who owns the temporary installation and record it. One business is responsible for the board, its protection and its inspection.
• Each business remains responsible for its own equipment plugged into it, and should not assume the host’s regime covers their tools.
• Do not let anyone modify the installation. Adding a board, extending a run or changing a connection is licensed work, whoever needed it.
• Check subcontractors’ gear on arrival. Their tags, their leads, their RCDs. It is your site, and a shock to their worker is your incident too.
• On a client’s operating site, their rules win — permits, isolation, approved equipment and sometimes an escort.

When something happens

• Do not touch the person while they may still be in contact. Isolate first — at the board, the RCD or the generator — or use a non-conductive means to separate them.
• Any electric shock is a medical event, regardless of how the person feels. Cardiac effects can be delayed, and the advice is assessment, not a cup of tea and back to work.
• Quarantine the equipment. Tag it out and remove it from service. It is both a hazard and the evidence.
• An electric shock is generally a notifiable incident in Australian jurisdictions, with obligations to notify the regulator and preserve the site — see our guide to incident investigation and notification.
• Notify the electricity regulator as well where required. Several jurisdictions have a separate electrical safety notification pathway on top of the WHS one.
• Investigate the system, not the person. The lead was damaged because of how leads are managed, not because someone was careless once.

What tenders and audits ask for

Electrical safety rarely gets its own tender criterion, but it appears inside WHS returnables and it is a reliable finding in client audits, because the evidence either exists or it does not.

• The register. Items, test dates, next due, and who tested. This is the artefact that gets asked for.
• Who your competent person is, and their training record.
• Your temporary supply arrangement for this project, and who installs and inspects it.
• The quarantine process for failed or expired equipment.
• How subcontractor equipment is verified on arrival.
• Your generator arrangements, including earthing verification and exhaust siting — the detail that shows genuine familiarity.

It also belongs in the WHS management plan rather than being left to a generic statement — see WHS management plans and SWMS for civil tenders.

Checklist

• Is all portable and hand-held equipment protected by an RCD, at the point of use?
• Are portable RCDs available for work from other people’s sockets?
• Is the RCD push-button test done regularly, and operating-time testing done at interval?
• Does anyone on site believe a tripping RCD is an inconvenience rather than a fault?
• Are leads construction-rated, kept off the ground, and never joined to make length?
• Is there a single taped repair anywhere on site?
• Do you have a register of electrical items with next-due dates, not just tags?
• Is the construction interval being applied, rather than the general workplace one?
• Is there a visible quarantine point for failed or expired equipment?
• Has the generator’s earthing arrangement been verified by a licensed electrician?
• Is the generator exhaust clear of pits, chambers, sheds and ventilation intakes?
• Can the generator back-feed anything?
• Are boards and leads elevated before rain, and connections kept out of water?
• Are lighting towers, welders, compressors and site sheds in the register?
• Is lithium battery charging done in a designated place?
• Does everyone know that repairs and installation work are licensed work?
• Is subcontractor equipment checked on arrival?
• Does the crew know not to touch someone still in contact, and that every shock needs medical assessment?

The short version

• Three electrical risks exist on a civil site; only the temporary supply and equipment you bring is entirely within your control, and it has the thinnest paperwork.
• Construction sites attract stricter rules than ordinary workplaces because of water, abrasion, earth contact and constant change.
• Portable and hand-held equipment must be RCD protected at the point of use. An RCD upstream of a long run may not be protecting the tool.
• An RCD protects against earth leakage only. It is the most important control, not the only one.
• Nuisance tripping is a fault being detected. Bypassing it is the decision that appears in fatality reports.
• Leads cause more incidents than anything else: use construction-rated leads, keep them off the ground, never join them, never tape a repair.
• The construction inspection interval is shorter than the general workplace one. Take it from the regulation and standard, not from habit.
• The tag is visible; the register is the evidence. Out of date means out of service, in a visible quarantine.
• Not every portable generator’s earthing arrangement lets a standard RCD operate. Have it verified for your unit by a licensed electrician.
• Generator exhaust near a pit, chamber or ventilation intake has killed people. Site it clear and downwind.
• Repairs, installation and connecting a generator to an installation are licensed electrical work.
• On shared supply, name who owns the installation, and check subcontractors’ gear on arrival.
• Every electric shock is a medical event and generally a notifiable incident. Isolate before touching anyone, and quarantine the equipment.

Sources and further reading

This guide is general information for Australian civil construction businesses and is not electrical, safety or legal advice. Requirements for residual current protection, inspection and testing intervals, competent person qualifications, temporary installations on construction and demolition sites, licensing of electrical work and incident notification are set by work health and safety and electrical safety legislation made separately in each state and territory, supported by Australian and Australian/New Zealand standards, and they differ between jurisdictions. This guide deliberately does not reproduce test intervals, trip currents, clearance distances or other numeric safety limits: take those from the current regulation and standard applying where you are working. Earthing arrangements for portable generators are a technical matter for a licensed electrician assessing the specific unit. Information is current as at October 2026.

• Work health and safety legislation and regulations as made in each Australian state and territory, which impose the duties relating to electrical risks at a workplace referenced in §02, §04 and §06, including residual current protection for construction work, inspection and testing obligations, and the competent person requirement. The intervals and technical criteria are set by the regulations and the standards they reference and are deliberately not reproduced here.
• The Australian/New Zealand standard for electrical installations on construction and demolition sites, and the associated standard for in-service safety inspection and testing of electrical equipment, which together govern temporary supply arrangements, switchboards, protection and the inspection and testing regime described in §03, §05 and §06. Where a project specification or client requires compliance with a standard, that requirement is contractual as well as regulatory.
• Electrical safety legislation and electrical licensing regimes, which operate separately from the general WHS framework in several jurisdictions and carry their own incident notification pathways referenced in §12 and their own definitions of licensed electrical work referenced in §10. Licensing differs materially between states and territories; sourced in full in our guide to contractor licensing by state.
• Related TenderBuilt guides carrying the primary-source detail referenced above: working near overhead powerlines, underground services and utility strikes, confined spaces, incident investigation and notification, WHS management plans and SWMS, and plant maintenance and availability.