14.1 Must-Know Numbers, Times & Thresholds

14.1 Must-Know Numbers, Times & Thresholds

Quick Answer: For open-book speed, pre-load a short list of NZ-practice anchors—30 mA shock-protection RCD class; 300 ms @ 1× IΔn / 40 ms @ 5× trip performance classically linked to ESR reg 24 unsafe criteria; IR 500 V DC, min 1 MΩ; 0.4 s / 5 s disconnection applications; Aspeq NZ$149.50 + GST; results ~24 hours; 3 fails in 3 months → 3-month stand-down; CoC copy within 20 days of completing the work and ESC within 20 working days of connection; records 7 years; CoC reg 65 / RoI reg 72 / ESC reg 74A; AS/NZS 3000:2018 cited since 13 Nov 2025; MEN only at main switchboard; Section 8 verification order; risk category → document chain. Then confirm every figure in permitted texts—do not certify from memory alone.

Why a Number Bank Still Matters on an Open-Book Exam

Open-reference does not reward candidates who “will look everything up from cold.” Every minute spent hunting for a residual-current rating or a certification regulation is a minute stolen from scenario stems, calculation extracts, and trap options. The strategy is dual: know the high-yield set cold, and know where it lives so verification is a 20-second flag flip, not a full index search.

Treat the tables below as a speed layer. They are curated for this study guide’s NZ EWRB electrician regulations pathway and align with earlier chapters. Editions and exact clause wording can differ—always confirm in the ESR 2010 and AS/NZS 3000 (and any other materials Aspeq permits for your sitting).

High-Yield Technical Numbers

Scenario A — mixed units trap. A stem asks whether a 30 mA RCD that trips in 320 ms at IΔn is acceptable under unsafe-criteria teaching. Candidates who confuse 30 mA (sensitivity) with 300 ms (time) or answer from “it felt fine” lose the mark. Route: residual rating check → trip-time table → reg 24 / product performance path in your books.

Scenario B — IR before energisation. An addition returns 0.4 MΩ at 500 V DC between actives/neutral and earth. Correct path: fail the IR criterion (classic 1 MΩ minimum), remediate, retest—not “close enough for CoC” and not skip to live EFLI/RCD.

Exam Logistics Numbers (Aspeq / EWRB Pathway)

These are process numbers, not Wiring Rules numbers. Stems about “what happens after three fails” test retake policy, not RCD physics. Keep them in a separate mental drawer from 30 mA / 0.4 s.

Certification Timeframes, Retention & Regulation Anchors

Memory string: 65 complies · 72 inspects · 74A connects safely · CoC 20 days · everything else 20 working days · requests 10 working days · keep 7 years.

Standards edition anchors

Risk category → document chain (teach cold)

Scenario C — high-risk incomplete chain. Excellent installation, neat CoC, immediate energisation, no Inspector RoI. The compliance chain is incomplete. The number bank does not help if you cannot map high-risk → reg 72.

MEN Link Location (One-Line Rule)

MEN link only at the main switchboard / main earthing point of the consumer installation—bonding neutral bar to earth bar there. Downstream, neutral and protective earth stay separated. Extra N–E links on sub-boards or final circuits are a classic fail pattern.

Verification Sequence Order (Section 8 Teaching)

Pre-livening: MEN restored, dead tests satisfactory (including IR ≥ 1 MΩ at 500 V DC classic teaching), area controlled. Test-button-only is not full RCD verification for Section 8 competence—instrument trip-time tests at 1× / 5× complete the story.

Flagging List for Physical Standards Books

Before exam day, mark allowed flags/tabs (annotations only as Aspeq permits—no loose sheets that break rules):

1. ESR — electrically safe/unsafe & reg 24 RCD unsafe criteria
2. ESR — PEW definitions & risk categories
3. ESR — reg 65 CoC, reg 72 RoI, reg 74A ESC family; timeframes/retention
4. AS/NZS 3000 — MEN / earthing arrangements
5. AS/NZS 3000 — RCD additional protection & residual-current applications
6. AS/NZS 3000 — disconnection times / ADS tables (0.4 s / 5 s contexts)
7. AS/NZS 3000 Section 8 — visual + test sequence & IR criteria
8. Companion standards index (3008 cable, 3012 construction, 3760 appliances, special installs)
9. NZECP 34 (A-level safe distances) and other ECPs you are permitted
10. Voltage-drop / maximum-demand worked examples or tables you may need under extract stems

Drill method: close the book, write the number bank from memory, open to each flag and confirm wording, re-close, re-write. On exam day, high-confidence items answer first then spot-check; low-confidence items open the flag before selecting.

Bottom Line for Section 14.1

Speed without honesty fails registration ethics; honesty without speed fails the clock. Internalise 30 mA · 300/40 ms · 500 V / 1 MΩ · 0.4/5 s · $149.50+GST · 24 h · 3-fail stand-down · 20 working days · 7 years · 65/72/74A · MEN at MSB only · Section 8 order · risk→docs, flag the homes of those facts, and still read the permitted text when the stem turns on a nuance.

Memory Aids (Quick Cards)

• RCD: 30 mA protects people; 300 ms at one times; 40 ms at five.
• IR: Five hundred volts, one megohm minimum—dead before live.
• ADS times: Point-four finals; five for feeders (context tables).
• Papers: Sixty-five complies, seventy-two inspects, seventy-four connects safe.
• MEN: One link at the main board—never a necklace of links.
• Sequence: See it, bond it, IR it, polarise it, connect-check it, then loop and RCD live.