Is a 17th Edition metal consumer unit still legal to fit?

[Felixx]

Hi looking for some guidance on consumer units. I currently have a plastic consumer unit that needs upgrading. I had a 16 way metal consumer unit which is 17 Edition amendment 3 compliant but a couple of electricians i have called in say they won't fit that and want me to buy another one that is 18th edition compliant. Both state they won't install it because it is not 18th edition. Can anyone confirm this is the case as you can still buy these 17th edition metal units? Thanks.

 

[Murdoch]

The names "17th edition" and "18th edition" are just marketing muck

Ask yourself what is the difference between the 2?

 

[Felixx]

The names "17th edition" and "18th edition" are just marketing muck

Ask yourself what is the difference between the 2?

Hi Murdoch thanks for your quick reply. The difference appears to relate to circuit breakers and the allowable current leakage between the two. I'm a general DIYer and some of the terms are just over my head but i can't see anything to suggest that the installers cannot fit 17th edition CU's and provide me with the NIC certificate following installation. I've tried speaking to my local building control who were as useful as a chocolate teapot, simply passing the buck back to the electrician!

 

[Murdoch]

The main difference between the 2 (assuming both are metal) is the label on the box and the lack of an SPD - which can be bought as an upgrade

You need to talk to decent sparks who know what they are doing because what you have heard so far is complete BS

 

[Fleeting]

As above there is no such thing as 17th and 18th Ed consumer units although manufacturers banded this about. It is not likely to comply with current requirements can you show a pic of it.

 

[SPECIAL LOCATION]

Few of my thoughts:

All new installation work should comply with current wiring regulations, (BS7671 18th edition Amend 2 since Sept 2022).
Also new circuits and CU replacements also require building regulations Part-P compliance notification..
Which typically involves an electrician signing paperwork to confirm compliance and accept liability for the design/install/testing of the work.

Consumer units are just enclosures with various protective components inside them..
Some are purchased empty and you select whatever components you require for a specific installation,
Some are sold ready-equipped with a random selection of protective devices that may or may not be applicable for all installations..
These ready equipped CU's are often sold as a "certain edition" compliant e.g. 16th , 17th 18th as and when regs change..
DIY outlets such as B&Q have a tendency to have these types of CU's... Which they then try to discount to shift stock when new regs become applicable!

As Murdoch said SPD's tend to be included in what are described as 18th edition CU's
Also any RCD's and/or RCBO's will tend to be type 'A' instead of type 'AC' for the current regs..
(Had a flyer come though today with a local wholesaler wanting to sell off 'AC' type RCBOs' at half price.
and I have seen similar type RCD's in the discount bin at our B&Q!).

Existing plastic enclosure CU's are still safe and functional... (they do not become dangerous just because regs have changed.)
Are you doing other alteration work that warrants replacing the CU?
How long have you had this CU?
Can you take it back for a refund?
Why did you purchase it without checking if it was suitable first?

Although you can get replacement protective devices for a CU to bring it up to current regs, This can be an expensive excerise.
If you know what you are looking for there are often deals with semi or fully equipped CU's that are cheaper than buying individual components.
e.g. some wholesaler have offers for an empty enclosures + a quantity of protective devices that you select what type and rating you rerquire.

Personally myself, I would not fit a new CU unless it was all Type A RCBO's and has surge protection installed in it.
If what you have is a dual RCD board with 2x AC RCD's I can understand the reluctance of other electricians wanting to install it.

 

[Murdoch]

FWIW the RCD issue is a total can of worms as most sparks don't understand the issues ................ but can be replaced

And I would say that a RCBO board with SPD is the way to go

 

[kerching]

16th, 17th, 18th edition boards? BOLLOCKS,!
As said before.
If it has to be swapped then RCBO on all circuits apart from SWA sub to a garage or similar
SPD
Metal

 

[Murdoch]

What also concerns me is that seemingly so few sparks have test kit that can deal with the variety of RCDs these days

 

[binky]

What also concerns me is that seemingly so few sparks have test kit that can deal with the variety of RCDs these days

can't say I've seen any for sale, mind you I've not been looking

 

[UNG]

What also concerns me is that seemingly so few sparks have test kit that can deal with the variety of RCDs these days

And if they had the correct test kit how many would know how to use it properly

 

[Sparksfly]

KT64 has some RCD A tests for many years...!!!

..................as already mentioned.... you are fine with a 17th ed board...you can always upgrade RCDs to type A later... if needed.

I think the main 17/18th "issue" was the dual RCD total ratings should have enough head room to take the load of the related MCBs avoiding overload. However, in real life I have seen plenty RCD's covering large total amperage without issues. Hello diversity!

SPD's - How many TV's, electrical goods, PC's etc have blown up due to transient voltages in the last 10/20 years?.... Well... you can REFUSE SPD's in your own house...YES.. it is perfectly okay to refuse them....YOUR choice...it can be put down as a non-compliance... a dedicated space on the certs... not a problem.

RCD's AC Vs type A/B/F - Perfectly okay to use type AC, however If you do use PV/EV they should be covered by a type A etc and any existing RCD upstream in the consumer unit should be compatible with the tripping characteristics of type A to avoid blinding. However, outside EV etc.. they are okay to use if you don't have too much DC stuff in your own home.
......I wonder how many earlier PV setups have type AC !!

.....Don't you just love marketing and binning type AC RCDs creating more damage to the environment.

 

[monkey5]

What also concerns me is that seemingly so few sparks have test kit that can deal with the variety of RCDs these days

As in testing the AC and A bits of the RCD? What are the requirements for testing an A type RCD?
Genuine question as wondering what others are testing on say a 12 way type A rcbo board.
Hard Hat on!

 

[Murdoch]

As in testing the AC and A bits of the RCD? What are the requirements for testing an A type RCD?
Genuine question as wondering what others are testing on say a 12 way type A rcbo board.
Hard Hat on!

Set tester to A type and push the test button .,,,

 

[Sparksfly]

Good question...
No hard hat required.(or type testing)....unless your singing (YMCA)......it is all here
https://electrical.theiet.org/wirin...nges-to-rcd-testing-in-bs-76712018plusa22022/

 

[Felixx]

Hey guys my thanks to you all for the helpful info, especially Special Location. A picture of the unit I bought is attached. I bought it just before the first lockdown - it was at half price at B&Q and I knew i would need it as i was having a new shower installed and the existing unit did not have any spare fuses in it. My fault for not thinking about changing regs.
3 years on too late to take it back now! The shower work has only recently been done and that has meant the CU now needs changing so the shower cable can be connected up. It sounds like I'll just have to end up writing this off and letting the installer buy a new one themselves otherwise I'll only end up buying the wrong one again!

 

[Fleeting]

What also concerns me is that seemingly so few sparks have test kit that can deal with the variety of RCDs these days

There is no requirement to have different test kit to test the variety of rcds we now encounter. Regardless of type they can all be tested in the same way as BS7671 only prescribes an AC test, see the Note in Regulation 643.7.1 a).

 

[Murdoch]

There is no requirement to have different test kit to test the variety of rcds we now encounter. Regardless of type they can all be tested in the same way as BS7671 only prescribes an AC test, see the Note in Regulation 643.2.1 a).

That might be written but my tester doesn’t like testing type A on the tour type AC setting

 

[Fleeting]

That might be written but my tester doesn’t like testing type A on the tour type AC setting

Maybe you need a 20 odd year old tester like mine which is still banging them off regardless of type.

 

[UNG]

There is no requirement to have different test kit to test the variety of rcds we now encounter. Regardless of type they can all be tested in the same way as BS7671 only prescribes an AC test, see the Note in Regulation 643.2.1 a).

What has the continuity of conductors got to do with the testing of RCD's
Or are you thinking of Reg 643.7.1

Maybe you need a 20 odd year old tester like mine which is still banging them off regardless of type.

Doesn't ncessarily mean it is testing them correctly or giving the correct results