This is the most consequential change to New Zealand electrical requirements in years, and outside the trade almost nobody has heard of it.
The change in one paragraph
The Electricity (Safety) Amendment Regulations 2025 came into effect on 13 November 2025. They updated around 440 referenced standards, and the headline one is AS/NZS 3000 — the Wiring Rules — moving from the 2007 edition to AS/NZS 3000:2018 including Amendments 1, 2 and 3.
The Government made several New Zealand-specific modifications to the standard in citing it. One of them replaces clause 2.6.2.2.3(b) so that RCDs providing protection against electric shock must comply with the requirements of a Type A RCD (to IEC 61009.1 or IEC 61008.1), or a Type F or Type B RCD (to IEC 62423).
Plain Type AC is out for new work. You must start using the newly cited standards from 12 November 2026.
Why Type AC is no longer enough
This is not bureaucratic tidying. It is a response to what buildings are now full of.
A classic Type AC RCD is built to detect a smooth, sinusoidal AC residual current. That was a sound assumption in a building of incandescent lamps, resistive heaters and induction motors.
Modern buildings are not that. Variable speed drives, LED drivers, switch-mode power supplies, solar inverters, EV chargers, UPS systems and half the equipment in a modern kitchen all rectify and chop the supply. When a fault develops downstream of that electronics, the residual current is frequently not a clean sine wave. It can be pulsating DC, or contain a smooth DC component.
A Type AC device can be blinded by this. Not slowed — blinded. Smooth DC content can magnetically saturate the detection core so that the device fails to respond to a fault it would otherwise catch instantly.
So you have a protective device that passes its test button, measures well on an AC trip-time test, and does not operate on the real fault. That is a considerably worse situation than having no RCD, because everyone believes there is one.
The four types, plainly
| Type | Detects | Typical use |
|---|---|---|
| AC | Sinusoidal AC residual current only | Legacy installations. No longer sufficient for new work under the cited standard. |
| A | AC plus pulsating DC residual current | The general baseline for new work under the new citation. |
| F | As Type A, plus mixed frequencies | Circuits with single-phase variable speed drives and similar. |
| B | As Type F, plus smooth DC residual current | Three-phase drives, EV charging, solar and other equipment producing smooth DC. |
Each type up the list detects everything below it plus more. Type is not the same thing as rated residual current — a device can be 30 mA and Type AC, or 30 mA and Type B. Both numbers matter and they describe different properties.
This is a plain summary to help you ask the right questions. Selecting the correct type for a specific circuit is a design decision for a registered electrical worker, informed by the equipment manufacturer's instructions and the cited standard. AS/NZS 3000 is copyrighted and sold by Standards New Zealand.
The dates that matter
The transition arrangements are more generous than the headline suggests, and worth getting right.
| Situation | Position |
|---|---|
| Existing installations | May continue to exist and be repaired so long as they are not unsafe. No time limit. |
| Repairs to existing installations | The old version of the standard may continue to be used. If the repair becomes an alteration or addition, that part needs the new standard. |
| Relocating, adding to or altering | You may use the new standard from 13 November 2025. Only the parts you change need to meet it. |
| Construction begun before 13 November 2025 | The old standard may be used until the installation is complete. No time limit. |
| Construction begun after 13 November 2025 using the old standard | Had to be completed by 12 November 2026. If unfinished, issue a Certificate of Compliance for the completed portion; the remainder must comply with the new version. |
| Construction beginning after 12 November 2026 | Must comply with the new standard. |
"Construction" here includes the design phase. Work can proceed under the old standard if the quote or tendering process was already under way. If you have a project in design now, this is a question to settle with your consultant rather than discover at inspection.
What this means for an existing building
For most building owners reading this, the answer is reassuring: you do not have to do anything on 12 November 2026.
Your existing installation is not rendered non-compliant. There is no requirement to rewire, no requirement to swap every Type AC device in the board, and no deadline hanging over you.
What you should do is different and more useful:
Know what you have. Most building owners cannot say what type their RCDs are. It is written on the device. An hour at the board with someone who knows what they are looking at gives you an inventory you will need eventually.
Understand where Type AC is a genuine risk right now, regardless of the regulations. If you have added EV chargers, solar, variable speed drives or a lot of electronic loads to a board protected by Type AC devices, the protection may already not be doing what everyone assumes. That is a safety question today, not a compliance question in November.
Plan replacement into work you were doing anyway. Board upgrades, tenancy fitouts, new plant. Changing a device during work already scoped costs a fraction of a standalone visit.
Do not panic-buy. We have already seen the November date used as a reason to quote whole-board replacements to people who need nothing of the sort.
The load compatibility clause
The type requirement gets the attention, but there is a second modification that may matter more in the long run. Inserted into clause 1.5.6.3:
"Any RCD that forms part of an installation shall be selected and installed to be compatible with the types of load intended to be used within the installation. Consideration shall be given for potential pulsating and constant DC fault currents and waveform distortion."
This shifts the question from "is there an RCD" to "is this the right RCD for what is plugged into it".
It is a designer's obligation, but it has a practical consequence for building owners: when the loads in a building change materially, the protection may need to change too. Adding EV chargers to a car park, or a bank of drives to a plant room, is not only a capacity question. It is now explicitly a protection-compatibility question.
If you are commissioning that sort of work, ask the question in writing.
Construction sites and transportables
Two more modifications worth knowing if you work in this space.
The citation of AS/NZS 3012:2019 modifies clause 1.4.17 to state that a portable socket outlet assembly is not considered to be a portable residual current device, and that all RCDs are to be Type A, or Type F or B. If your site documentation uses PRCD and PSOA interchangeably, they are now formally distinct. See portable RCDs and PSOAs.
It also inserts an explicit protection for existing equipment:
"Nothing in this standard requires the upgrading of an existing RCD in a transportable structure or transportable installation merely because it does not provide protection against pulsating DC current."
That sentence is not widely known and has saved a lot of operators a lot of money. If someone is telling you every RCD in your fleet of site huts must be replaced by November, that is the clause to put in front of them.
What to do before November
An honest, short list.
- Inventory your RCDs. Type, rating, and which circuits each one protects. Most boards have no schedule and this is worth doing regardless.
- Get them measured, not button-tested. If you do not have trip times, you do not know their condition. See push-button vs trip-time testing.
- Flag the circuits with heavy electronic loads and ask whether Type AC is appropriate there today.
- Check any project in design for which standard it has been scoped against.
- Budget replacement into planned work, not as an emergency programme.
- Ignore anyone quoting urgency. The transition arrangements are explicit and generous, and existing installations are protected. Anyone telling you otherwise has not read the WorkSafe guidance.
Related: when are RCDs required in New Zealand and test and tag on construction sites.