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

Talk Electrician Forum

Help Support Talk Electrician Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
What has the continuity of conductors got to do with the testing of RCD's
Or are you thinking of Reg 643.7.1

Doesn't ncessarily mean it is testing them correctly or giving the correct results
Yes typo and edited.
Meter is calibrated and there is no more doubt over the results than any other instrument regardless of age.
 
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!


It is possible to get Surge Protection and 'type A' RCD's and/or RCBO's for that MK consumer unit...

e.g.
https://www.tlc-direct.co.uk/Products/MK5680S.html
https://www.tlc-direct.co.uk/Main_I...ontactors_and_RCBO/index.html#RCBOs_30Ma_7000
https://www.tlc-direct.co.uk/Products/MK6820S.html

But as I said earlier by the time you add up all the bits + Vat, it can be cheaper buying a new board anyway!?

Examples of near like for like comparisons to what you already have are;
https://www.tlc-direct.co.uk/Products/MKYS8666SMET.html
or
https://www.tlc-direct.co.uk/Products/MKYS8678SMET.html

Although neither would be my own personal choice as you are still limited by a dual RCD CU!

Dual RCD boards can be a major inconvenience if you have an RCD trip but are unable to reset it due to a neutral - earth fault...
Which means you can have no power to half your installation until you can find and fix the problem..

(I have encountered numerous faults involving dual RCD CU's that have seriously inconvenienced various customers,
hence why i stopped fitting them many years ago.)

A full RCBO board with surge protection is a much better long term investment in my opinion.
 
According to Napit following their webinar this week. If the board has type AC rcds then it is not compliant to 18th Edition unless you can confirm that there will be no appliances connected that are dc leaking.

As this would be very hard to confirm for socket circuits then you have to fit type A.

This maybe the reason the electricians have refused to install it. The photo doesn't show clearly the type of rcd it has fitted.

On a side note again from the webinar. If you are doing work on a circuit and it has dc leaking accessories and a type AC rcd or rcbo then you have to change the rcd/rcbo in order to issue a compliant certificate.

So a simple additional socket could potentially become a board change as well if the board has obsolete components.
 
Yes typo and edited.
Meter is calibrated and there is no more doubt over the results than any other instrument regardless of age.
But the reg quoted from BS7671 references BS61557-6 which has been updated twice in the last 20 years and as recent as early 2022
I agree that any meter that can prove the tripping of an RCD is better than nothing, but it begs the question which BS takes precedence and should it be noted on any test certs
Reg 643.7.1 is certainly at odds with a lot of the information put out there and possibly an oversight on the IET's part when amending the regs when DC blinding of RCD's / RCBO's is such a hot topic and the reason behind the many types of RCD / RCBO that have become available in recent years
 
Imo its not a problem. I had one of these fitted to my workshop/garage last year to accommodate my solar. A decent sparky would swap out what is needed to meet your needs.
The problem you may be having is, you supplied the cu. Not all tradesman like that. Give a few more a ring and see their responce
 
On a side note again from the webinar. If you are doing work on a circuit and it has dc leaking accessories and a type AC rcd or rcbo then you have to change the rcd/rcbo in order to issue a compliant certificate.


......I do think its gone silly .......typically not thinking it through.

I am with Andy1733 on this one... your CU is not a problem....If it is installed tested incl RCD tests.

If people are that worried about a freak domestic RCD blinding incident with regard to DC leakage then press the RCD button with all electrical things connected. If it does not trip then it could be DC leakage at a significant amount or a failed RCD...disconnect load side, test again
 
Imo its not a problem. I had one of these fitted to my workshop/garage last year to accommodate my solar. A decent sparky would swap out what is needed to meet your needs.
The problem you may be having is, you supplied the cu. Not all tradesman like that. Give a few more a ring and see their responce
Shouldn't fit solar to a dual rcd consumer unit.
 
Also, which was a learning point for me. Type A and F will not trip due to dc leakage, only type B will.

Type A and F just aren't blinded as easily.

My fluke 1662 tests type AC, A and F.

I have found occasionally some AC rcds don't like being tested in type A mode.
 
Imo its not a problem. I had one of these fitted to my workshop/garage last year to accommodate my solar. A decent sparky would swap out what is needed to meet your needs.
The problem you may be having is, you supplied the cu. Not all tradesman like that. Give a few more a ring and see their
Shouldn't fit solar to a dual rcd consumer unit.
I though you shouldn't fit solar to any rcd
 
Imo its not a problem. I had one of these fitted to my workshop/garage last year to accommodate my solar. A decent sparky would swap out what is needed to meet your needs.
The problem you may be having is, you supplied the cu. Not all tradesman like that. Give a few more a ring and see their

I though you shouldn't fit solar to any rcd
If planned correctly then you can avoid an rcd,
 
The metal CU is absolutely fine, in fact i have recently fitted several, however i ditched the internals and went full RCBO. Pic attached, I'm sure someone will give me a flaming for something in this pic? If only i new what it was now I could Photoshop it in or out ;-)
Cheers
Stu
 

Attachments

  • 20230106_New DB Installed.jpg
    20230106_New DB Installed.jpg
    741.6 KB · Views: 3
I did sharpened. I believe fleeting has misunderstood my post. My solar is connected to the non protected side of the consumer unit
Maybe I did but you did not make it clear your consumer unit differed from the one pictured.
 
The metal CU is absolutely fine, in fact i have recently fitted several, however i ditched the internals and went full RCBO. Pic attached, I'm sure someone will give me a flaming for something in this pic? If only i new what it was now I could Photoshop it in or out ;-)
Cheers
Stu
I'm going to be critical here but that doesn't look great. Some of the flyleads don't appear to have ferrules fitted and the marking tape left on the conductors is messy. The flyleads should have been pre installed and tucked out of sight to give improved access for future testing.
 
Bit of what looks like wood on the right hand side presumably to hold the units upright?
 
Stu boy
The metal CU is absolutely fine, in fact i have recently fitted several, however i ditched the internals and went full RCBO. Pic attached, I'm sure someone will give me a flaming for something in this pic? If only i new what it was now I could Photoshop it in or out ;-)
Cheers
Stu
Why would you put a photo up you know you will need a tin hat
Next time take more time taking a photo it makes the CU look bad
 
Top