What Are The Amendment 2 Wiring Changes? | Checkatrade
Review a Trade

Have you completed a project recently? Let your tradesperson know how they did.

Advice Centre

Get Inspired! Check the latest industry expertise and read insider tips from our vetted tradespeople.

Search For A Trade

We interview and vet all our tradespeople to ensure they meet our high standards.

Join Checkatrade

Join us and benefit from the millions of potential customers who use Checkatrade to find reliable tradespeople.

Advice Centre

Grow your business! Check out top tips and expert advice for boosting your reputation online.

Login To Your Account

Edit your profile, view callback requests and ask for feedback from customers.

What are the BS7671 amendment 2 wiring changes?

BS7671 amendment 2 changes came into effect in 2022 – make sure you’re up to date with the changes and what they mean for electrician businesses.

Amendment 2 of the 18th Edition IET Wiring Regulations (BS 7671:2018) was announced at the end of March 2022. The previous amendments (BS7671:2018+A1:2020) have been withdrawn at the end of September 2022. But what does BS7671 amendment 2 mean for you?

As part of your electrician marketing plans, letting your customers know that you’re up to date with the latest regulatory changes can help to build trust. You’ll need to know the BS7671 amendment 2 changes anyway, and speaking about them in your marketing demonstrates your care and reliability.

Fusebox Shop have taken a more detailed look at the BS7671 amendment 2 changes, explaining what they mean for electricians and the key changes you need to know.

Two significant changes to Section 443

  • The removal of the risk assessment – this will mean that the installation of surge protection devices can no longer be decided via a calculation
  • The removal of the special dispensation for single dwellings. They are now to be considered along with all other electrical installations

Regulation 443.4.1

Regulation 443.4.1 has been amended, changing the need for protection against transient overvoltages. Protection should be in place where an overvoltage could:

  • Result in serious injury to, or loss of human life, or
  • Result in failure of a safety service, as defined in part 2, or
  • Result in significant financial loss or data loss

For all other cases SPDs shall be fitted to protect against transient overvoltages.

This is unless the owner of the installation declines such protection and wishes to accept the risk of damage to both wiring and equipment as tolerable. You’ll need to discuss this with your clients to make sure they understand the potential impact of this .

The requirement to install SPDs where the consequences could result in serious injury to, or loss of human life, is the same as previously stated in amendment 1.

We see a big shift in indent two, which requires an SPD to be installed where the consequences could result in the failure of a safety service as defined in part 2.

rewire a 2 bed house

BS 7671

BS 7671 defines safety services as: “An electrical system for electrical equipment provided to protect or warn persons in the event of a hazard, or essential to their evacuation from a location.”

This will mean that any distribution board supplying electrical equipment that would fall into the definition of a safety service, as described above, will require an SPD.

Therefore, now that domestic installations are not exempt from these requirements, a smoke alarm that is supplied from a consumer unit, rather than a battery, must be protected by an SPD.

Grow your business with Checkatrade

Find out everything you need to know about becoming a Checkatrade member

Discover more

Surge protection devices

Indent three is similar to the previous requirement. Previously, an SPD should be installed where commercial or industrial activity could be interrupted.

The requirement now is that an SPD should be provided where the consequence caused by overvoltage could result in significant financial or data loss. This leads on to the final requirements of the regulation.

The basic position of section 443 is now that SPDs should be installed.

In practical terms, most installations will have distribution boards that require surge protection due to the indents above.

It would only be distribution boards that did not require surge protection, as no circuits outlined in regulation 443.4.1 were present.

You’ll then need to make sure you speak to your client to make sure that no unacceptable losses occur from overvoltage, while also considering the requirements to protect against switching overvoltages from regulation 443.4.2.

Regulation 443.4.2

Protection against overvoltages shall be considered in the case of equipment likely to produce switching overvoltages or disturbances exceeding the applicable rated impulse voltage of equipment according to Table 443.2.

This includes where inductive or capacitive equipment, such as motors, transformers, capacitor banks, storage units or high current loads are installed.

Section 443 details where surge protection devices need to be installed, however, what is not clear is the type of device required.

Generally, type 2 SPDs will be used for most installations, but type 1 devices will be needed in certain circumstances:

For all other circumstances, a type 2 device will be sufficient to provide adequate protection for distribution boards.

Where protection against overvoltages is required for specific equipment, a type 3 device may be used to provide protection.

Grow your business with Checkatrade

Find out everything you need to know about becoming a Checkatrade member

Discover more

Section 712

Regulation 712.443.101

Where protection against transient overvoltage is required by section 443, such protection shall also be applied to the DC side of the PV installation.

When the inverter incorporates an SPD, it is only considered as fulfilling the SPD requirement if the manufacturer specifies its use for the DC side of the PV installation. Otherwise, it will need an external SPD.

Varistors included in the inverter are not considered an SPD.

This will mean that if the electrical installation requires surge protection to be fitted to comply with section 443, as discussed above, SPDs would now also need to be installed on the DC side of the installation to protect both the PV panels and the inverter.

Surge protection devices designed for use on the DC side of a PV system are designed to a different standard than SPDs used in low-voltage installations.

Although they are still described by using type 1 and type 2, as explained above, where type 1 devices are to protect against direct lightning, it is extremely important that only devices designed for use on the DC side of a PV installation are used.

All SPDs installed on the DC side of a PV installation should comply with BS EN 61643-31. Generally, the SPD will be a Type 2, unless the building has an external lightning protection system.

Section 514

Regulation 514.16.1

The presence of SPDs in an installation should be indicated by an information notice at or near the relevant distribution board(s).

The requirements of this regulation don’t need to be applied for domestic (household) premises or similar simple installations.

The information will need to be recorded on the appropriate certification for initial verification. They’ll need to be complete with Guidance for Recipients as detailed in Appendix 6, and issued to the person ordering the work.

The BS7671 amendment 2 changes to the 18th Edition IET Wiring Regulations might not be huge changes. But there are many shifts in installation rules and safety requirements, and it’s essential that you understand them.

You’ll need to know which requirements need to be explained to your customers so that they can be fully informed. While you’re brushing up on best-practice regulations, make sure you’ve also got the essential tools for electricians.

Guest post by Fusebox Shop

Grow your business with Checkatrade

Find out everything you need to know about becoming a Checkatrade member

Discover more

Tell us what you think

Please note, you cannot leave a review, or contact a tradesperson by commenting.

Your email address will not be published. Required fields are marked *

What others think of this article:

No comments yet!

More content like this

Social media marketing ideas for gardeners and landscapers

Boost your business and find more clients by using some of these social media marketing ideas for ga...

Read more
How to grow a cleaning business

In order to expand your cleaning business, you’ll probably want to consider a business growth plan...

Read more