Damaged electrical equipment is a recognised cause of workplace fires and electric shock. Test and tag is the process of visually inspecting, electrically testing and labelling portable appliances to confirm they are safe to use. In Australia it is governed by AS/NZS 3760, and doing it properly satisfies WHS Act duties and gives you documented proof of compliance when a regulator or insurer asks.
This guide is for electricians, safety officers, facilities managers and site supervisors who need a repeatable procedure for testing and tagging portable electrical equipment on construction sites, in warehouses or across office portfolios.
Before you start
Gather your portable appliance tester (PAT), durable test tags, a test and tag checklist and a pen. Confirm the PAT's own calibration is current, because an out-of-calibration tester makes every result it produces indefensible. Know which appliance class you are testing before you start: Class I equipment has a metal chassis connected to earth (kettles, angle grinders), while Class II relies on double insulation and carries the square-within-a-square symbol (phone chargers, plastic-bodied drills).
Step-by-step test and tag
1. Visually inspect the appliance
Before connecting the tester, check the appliance for damage, cracks, burns, staining, moisture ingress or missing covers. Confirm the rating label is legible, guards and ventilation openings are in place, and the appliance suits its operating environment. The visual inspection catches most faults, so if it fails here, do not proceed to electrical testing.
2. Visually inspect the cord and plug
Run your hands along the full length of the cord looking for cuts, abrasion, kinks, joins or exposed conductors. Inspect the plug for cracks, bent pins, burn marks or loose connections. Confirm the cord grip is secure at both ends and reject any cord with taped repairs or unapproved joins.
3. Connect the portable appliance tester
Switch the appliance off. Plug it into the PAT tester and, for Class I equipment, connect the earth lead clip to an exposed metal part. Select the correct test sequence for the appliance class.
4. Run the electrical tests
For Class I, run earth continuity first, then insulation resistance. For Class II (double-insulated), skip earth continuity and run insulation resistance only. Where the tester supports it, also run a leakage current test under load. Record every reading rather than just a pass/fail, so a slow drift towards the limit is visible over successive tests.
5. Apply the test tag
If the appliance passes, attach a durable pass tag showing the test date, next test due date and the tester's name. If it fails, apply a fail tag or a danger tag and remove it from service immediately. On construction sites, tags are commonly colour-coded by quarter so an out-of-date tag is obvious at a glance.
6. Record the result in the register
Enter the result into your register: appliance description, asset ID, serial number, location, test date, tester name, individual readings, pass or fail status and next test due date. Retain records for the life of the appliance.
Test types
The table below summarises the core tests and their pass criteria under AS/NZS 3760.
| Test | What it measures | Pass criterion | Applies to |
|---|---|---|---|
| Earth continuity | Resistance of the earth path from plug pin to exposed metal | Less than 1 ohm (a small allowance applies to long leads) | Class I only |
| Insulation resistance | Integrity of insulation between live conductors and earth | At least 1 megohm at 500 V DC | Class I and Class II |
| Leakage current | Current leaking from live parts under normal load | Within the AS/NZS 3760 limit (Class II not exceeding 1 mA) | Class I and Class II |
| Polarity | Correct wiring of active, neutral and earth conductors | Correct orientation confirmed | Leads, power boards, rewirable plugs |
Portable residual current devices (RCDs) are handled separately: AS/NZS 3760 covers both the push-button operation check and a trip-time test, and RCDs protecting portable equipment on site should be tested more often than the appliances plugged into them.
Testing intervals
AS/NZS 3760:2022 recommends test frequencies based on the environment and how hard the equipment is used. The intervals below follow the standard's guidance.
| Environment | Interval |
|---|---|
| Construction and demolition sites | 3 months |
| Hostile environments (wet, dusty, high vibration) | 3 to 6 months |
| Factories, workshops and warehouses | 6 months |
| Commercial kitchens and hospitality | 6 to 12 months |
| Hotels, retail and similar commercial premises | 12 months |
| Offices and low-risk environments | Up to 5 years |
These are the standard's recommendations, not black-letter law, but regulators and courts treat them as the benchmark. Construction and demolition sites sit at the strict end because equipment is constantly moved, flexed and exposed. Deviating from the intervals without a documented risk assessment is difficult to defend.
Regulatory requirements
In Australia and New Zealand, AS/NZS 3760 is the primary standard for in-service safety inspection and testing of electrical equipment. It defines who can test, which tests to perform, the pass criteria and the recommended intervals. It is not legislation in itself, but it is referenced in the WHS regulations and codes of practice across every state and territory.
Under the WHS Act, a PCBU must ensure, so far as is reasonably practicable, that electrical equipment at the workplace is safe. Non-compliance can bring improvement notices, prohibition notices and prosecution. A competent person under AS/NZS 3760 is a licensed electrician or someone who has completed a recognised test and tag course and can demonstrate competence with the equipment. Some states and some sites go further and require a licensed electrical worker, so confirm your local requirement before assigning the task. For operators working under overseas rules, the nearest equivalents are the UK Electricity at Work Regulations and, in the US, the general electrical safety duties under OSHA, neither of which mirrors the AS/NZS 3760 interval regime.
