4Information required in Certificate of Test#

4.1Test instruments#

All test equipment shall comply with the relevant requirements of AS 61010.1 and suitable for its intended purpose and be inspected regularly, particularly after extended periods of storage, to ensure that it remains operational and safe and internal batteries are adequately charged.

Table 4.1 lists test equipment and associated category requirements as defined in Section 6.7.4 of AS 61010.1. Category voltage requirements will depend on measurements being taken, either phase to neutral or phase to phase. Probes need to be selected accordingly.

Before commencing any of the tests in Section 4.4 below, the Contractor must ensure that all tools and electrical equipment are selected, serviced, and calibrated properly, and all details including type, serial number and the latest calibration date must be clearly shown in the CoT.

4.2Installation data#

The information contained under “Installation data” pertains to the types of circuits, electrical equipment, wiring and switchgear for the entire installation. This information forms an essential part of the test certificate and also serves as an inventory of the electrical installation for future reference.

4.2.1Circuit number and Phase#

The circuit number and phase shall be as displayed in the as-constructed design drawing and documentation. If no drawing is available, a complete sketch of the installation from the point of supply to each circuit termination must be provided.

4.2.2Circuit designation#

The circuit designation describes whether the circuit is a Consumer mains, Submains or a final subcircuit. Refer to AS/NZS 3000 for the exact definition of these terms.

4.2.3Circuit Load#

The circuit Load in Amperes must be recorded. For the Consumer mains this is simply the maximum demand, and for the submains it is the load in each circuit.

4.2.4Type of wiring#

Refers to the cable characteristics such as insulation, sheathing, conductor type, number of cores and CSA (Cross-Sectional Area). The permissible characteristics are defined in TRUM Vol. 4 Part 3 and MRTS256.

4.2.5Number of points served#

This refers to the number of equipment attached at the end of the circuit.

4.2.6Maximum permitted disconnect time#

This is typically either 0.4s or 5s.

4.2.7Overcurrent Protective device type and rating#

A protective device is either a fuse, a Type B MCB, Type C MCB, Type D MCB, RCD or RCBO, each with their relevant rating in kA, A and mA (for RCDs).

4.3Visual Inspection#

Visual inspection is to be completed to ensure that there are no local hazards prior to completing the prescribed tests.

All visual inspection shall be conducted in accordance with Section 2 of AS/NZS 3017. The contractor must consider all items in the check list in Section 2.2 of AS/NZS 3017. A tick () under the visual inspection item of the CoT is interpreted as an affirmation by the Contractor that all items in the checklist were considered and, as a result, the relevant requirements of AS/NZS 3000 are satisfied.

4.3.1Labelling#

The visual inspection must also ensure that all equipment, including switchgear, cables and terminals in the installation are clearly labelled to assist in subsequent periodic verification.

4.4Test results#

4.4.1Continuity of the earthing system#

The earth continuity test shall meet the requirements of AS/NZS 3000 and shall be tested in accordance with the procedures outlined in Clause 4.4 of AS/NZS 3017. The resistance of the main earthing conductor, the protective earthing conductor, and equipotential bonding conductors (in ohms) shall be recorded. The contractor shall record whether the protective earth exceeds the 0.5Ω, then earth is deemed insufficient and ensure the project manager has been notified.

4.4.2Insulation resistance#

The insulation resistance test shall meet the requirements of AS/NZS 3000 and be tested in accordance with the procedures outlined in Clause 4.5 of AS/NZS 3017.

For Mains & Sub Mains the insulation resistance (in Mega-ohms) between Phase conductors, Phase-to-Neutral, Phase-to-Earth, and Neutral-to-Earth shall be recorded.

For final Sub Circuits the insulation resistance (in Mega-ohms) between Phase-to-Earth, and Neutral-to-Earth shall be recorded.

For traffic signal multicore cables the insulation resistance (in Mega-ohms) between Active Cores-to-Earth and Neutral-to-Earth shall be measured. For each run, the Neutral-to-Earth and the Active-to-Earth resistance shall be recorded.

4.4.3Polarity#

The polarity test is intended to ensure that no shock hazard results from the incorrect connection of active, neutral, and earthing conductors and shall be tested in accordance with the procedures outlined in Clause 4.6 of AS/NZS 3017.

4.4.4Verification of FLI/EFLI (fault-loop impedance / earth fault-loop impedance)#

The fault-loop impedance of a circuit is measured as per certificate of test, if a fault of negligible impedance occurs between an active conductor and a protective neutral / earthing conductor or an exposed conductive part, sufficient current will flow in the fault-loop to cause a protective device to operate within a specified disconnection time.

The reference temperature for measuring the FLI/EFLI shall be recorded in the provided space in accordance with the principles outlined in Section 4.4.4.1 below.

The FLI/EFLI shall be measured in accordance with the procedures outlined in Clause 4.8 of AS/NZS 3017, at the following locations:

• At the termination of the Consumers mains
• − MSB main switch
• − Traffic Signal controllers
• − ITS cabinets
• At the furthest termination point of each circuit
• − poles (lighting and signals)
• − mast arms (ITS pole)

4.4.4.1Selection of EFLI testing temperature#

It is the responsibility of the Contractor to select the appropriate reference temperature for evaluating the EFLI (Earth Fault Loop Impedance) of the new installation.

For most installations where there is a much lower amount of current flowing relative to the current carrying capacity, a conductor temperature of 20°C can be assumed. This can be considered a worst case scenario.

The EFLI values shown in AS/NZS 3017 and AS/NZS 3000 are based on a conductor temperature of 75°C and should only be used when the conductor is operating at maximum permissible current, assuming this is the maximum temperature for the insulation.

The temperature quoted in the design documentation on which the installation is based, can only be used as a reference temperature if it can be proven that it is equivalent to the operating conductor temperature as installed.

Notwithstanding the above general guidelines, the Contractor shall use thermal imaging or equivalent means in order to verify or select the appropriate temperature.

Depending on the selected temperature, the EFLI table to be used shall be in accordance with Section 5 below. The Contractors Registered Professional Engineer Queensland (RPEQ) Electrical shall determine suitable alternative EFLI values where required, taking into account the specific site geometry and ambient conditions.

4.4.5Operation of RCDs#

Where applicable, testing of an RCD is carried out to ensure that the RCD operates and disconnects the designated circuit. The value to be recorded is the tripping time in milliseconds (ms).

A number of traffic controllers are equipped with a RCD protected socket outlet, which is designed for ancillary electrical equipment. In general, RCDs are installed in accordance with the requirements of the TRUM Vol 4 Part 3.

A visual inspection is required to make sure these RCD protected socket outlets are not subject to any operation of traffic signals. A tripping time test of the integrated RCD is required using the RCD tester in accordance with the procedures outlined in Section 3.7 of AS/NZS 3017, to confirm tripping time does not exceed 300ms. The use of the integral test button is not acceptable.