施工现场供电计算器

How this is calculated#

The tool gives the supply arrangement and the RCD protection for a construction or demolition site. It reads AS/NZS 3012:2019.

1. Supply arrangement. You pick the source, such as a distributor main. The tool finds the supply clause, here Cl 2.1.1(a).
2. Additional protection. It reads Cl 2.4.6.1 for the circuit type and the exceptions. It says whether RCD protection is required.
3. Residual current. It gives the maximum rated residual current for that circuit.
4. Test intervals. It reads Table 6 for the inspection and test interval of the equipment.
5. RCD tests. Table 6 also gives the push-button test and the operating time test.
6. Switchboard points. It points at Cl 2.3.4 for socket‑outlets and Cl 2.4.4 for the isolating switch marking.

Worked example#

• Final subcircuit from a distributor main, portable equipment. RCD protection is required at 30 mA. The inspection and test interval is 3 months. The operating time test is also 3 months. The push-button test is daily while the RCD is in use.

Limits#

The RCD must trip on every active conductor and the neutral. Where a board feeds two or more lighting circuits, spread them across the RCDs. New Zealand sites also complete a Record of Assessment in the Appendix G form. The tool does not size cable. It does not check the cord length.

The tool gives one supply arrangement at a time. Pick the arrangement that matches the board in front of you. Then read the clause the tool names. Test the RCD on the site, as the intervals say. Record the results with the date.

See also: Construction site supplies to AS/NZS 3012, Builder's pole, RCDs and cord lengths and Site cord length.