Discuss 100A DP Isolator Installation Between Meter and CU in the UK Electrical Forum area at ElectriciansForums.net

Murdoch, does it not specify in BS7671 that all supplies must now be 25mm regardless?

No - but the "pretty" pictures in the OSG do suggest this is the case.

When I do a CU change I carry 25mm tails, 16mm GY and 10mm GY and the appropriate Henley blocks and MET's - then I can cover each eventuality....

If its a new build I certainly would fit 25mm tails.
 
421.1.201 as everyone knows requires the enclosures of CUs and similar switchgear to be made from a non-flammable material (essentially metal).
However 421.1.201 also requires that they comply with BS EN 61439-3, which most everyone seems to forget.

So if your DP 100A isolator or switchfuse does not comply with BS EN 61439-3, you cannot install it irrespective of whether the enclosure is metal or even if you enclose it within a metal cabinate or enclosure.

Unfortunately, BS EN 61439-3 only applies to CUs, so you won’t be able to install either a DP 100A isolator or switchfuse.
 
Should point out, that the previous post only applies if you believe DP 100A isolators and switchfuses are similar to CUs.
If you don’t believe they are similar, then you can still install them and they can be plastic, metal or whatever.

I believe I'm paying too much tax to HRMC. I'm arguing, they are not believing.
 
421.1.201 refers to consumer units and similar switchgear. In BS7671 Switchgear is defined as 'an assembly of main & auxiliary switching equipment for operation, regulation, protection or other control of an electrical installation'. That's sounds like an isolator to me?
an isolator does not have auxiliary switching equipment, so is not "similar switchgear".
 
an isolator does not have auxiliary switching equipment, so is not "similar switchgear".

See now I read that as main (and/or) auxiliary switching.... Reg 421.1.201 refers to 'similar switchgear', which is not defined. The 'grown ups' in the vid I posted seem to suggest (to me) that the REC2 isolators could fall under this reg.

But hey hoe, who am I to say. I keep asking these bodies, but no one appears to want to give a definitive answer. I know some forum members here, are full IET members. Perhaps they could ask them for some guidance on our behalf? :)
 
I needed tom upgrade my DNO fuse to 100A so needed to increase my tails to 25mm.
Contacted DNO and they agreed to replace tails and increase fuse to 100A
I ordered a 100A isolator (in a plastic enclosure)
When the DNO arrived I asked if they would fit supplied isolator. They were happy to and even added their seals to it. I asked about it needing to be a metal enclosure and they said it was part of their installation so outside the requirement.
 
I needed tom upgrade my DNO fuse to 100A so needed to increase my tails to 25mm.
Contacted DNO and they agreed to replace tails and increase fuse to 100A
I ordered a 100A isolator (in a plastic enclosure)
When the DNO arrived I asked if they would fit supplied isolator. They were happy to and even added their seals to it. I asked about it needing to be a metal enclosure and they said it was part of their installation so outside the requirement.

Thanks for that (#24), but we are arguing, sorry discussing whether us electricians who have to comply with BS7671, can fit metal or plastic in this situation. :)
 
It’s not a question of whether it’s metal or plastic, the Regulation allows for either.
It can be metal, or it can be plastic inside a metal box.
The question is whether the item (whether it’s a CU or similar) meets the standard of BS EN 61439-3.

Oh and by the way, it’s not similar switchgear, it’s similar switchgear assemblies.

See here: http://electrical.------.org/wiring-matters/55/-files/consumer-units-pdf.cfm?type=pdf
 
It’s not a question of whether it’s metal or plastic, the Regulation allows for either.
It can be metal, or it can be plastic inside a metal box.
The question is whether the item (whether it’s a CU or similar) meets the standard of BS EN 61439-3.

If we're being picky, its not metal, but an enclosure manufactured from non-combustible material or in enclosed in a cabinet or enclosure constructed of....blar blar.

Ferrous metal is an example of etc. Aren't you a remember of the IET? Ask em for a definitive definition of 'similar switchgear', and we can put this one to bed, forever.;)
 

Reply to 100A DP Isolator Installation Between Meter and CU in the UK Electrical Forum area at ElectriciansForums.net

Similar Threads

D
Hi, I have received conflicting advice about Main Isolator Switches and would appreciate forum member's help to plan a way ahead. Looking to the...
Replies
5
Views
2K
Deleted member 155212
D
Hi all -- full disclosure I am a 'DIY-er' but wanted to post here for greater visibility seeing as I certainly won't be doing this work myself...
Replies
21
Views
4K
Trying to organise a CU replacement at home. It's a 1930s property. It's got a 10way CU but with no RCD protection. Was after a larger unit with...
Replies
65
Views
4K
Hello again, Was looking at installing yet another dedicated consumer box for my EV charger off the henley blocks and i noticed that a meter...
Replies
11
Views
2K
Hi, need your advise please as need to take supply for Electric car charger from the meter cupboard. This meter cupboard has an isolator and...
Replies
16
Views
2K

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock