Discuss Fused Neutral in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

the pict

-
Mentor
Reaction score
247
I have had a preliminary look at a job I am quoting for,it is a 3 phases are protected by 100A fuses as is the neutral, am I right in saying that the practice of fusing neutrals is a departure or is that just in final circuit distribution, I will be refering to the regs later today on some other matters but if anyone can give me the heads up on this particular issue I would be gratefull
Pict
 
a lnk would be a better description. a blank implies there's nothing behind the cover.
 
I am aware that the regs state that a fuse should be fitted in the line conductor only but I cant ascertain if this reg refers to the incoming supply, as to the possiblity of a unfused link inthe N I cannot say but it definately says 100A on the holder
P
 
it says persil washes whiter on buses, but they don't take in washing. you can't go by what label is on the holder. the " no fuse in neutral" applies to supply fuses as well as for final circuits.
 
Cheers Tel 132.14.1 & 14.2 are vague and do not specifically mention incoming supply , so thanks for adding clarity
Pict
 
i would say that that is because BS76571 does not cover DNO's equipment.
 
your right of course, and once again another round of phone calls to get them out with the usuall " can I have the customer account number,the post code, can the engineer park at the premises, will he need a ladder, will the customer be present, are there any dogs at large, etc etc thats if I get through to engineering at all as they have changed all the numbers I had
Pict
 
The only time you will see a fused DNO neutral is on very old service heads that will almost certainly be of cast iron construction. If this is what you have then contact your DNO to replace.

These old service heads have been deemed dangerous and should have all been replaced by Sept 2011, but there are still thousands of the things still left in service.....
 
As Eng has said, there are 1000's of these old cut outs around - I've had four replaced in the last few months. To be fair, Scottish Power change these on request foc (though I always say they are crackling, warm etc!).
On Arran, I'm guessing it's SSE?
Managing to dodge the worst of the storms Pict? I saw Ardrossan yesterday - very breezy!
 
On a 3-phase 4-wire service it was never correct to fuse the neutral and I have never seen it done. This is due to the likelihood of over-voltage on the load side if the neutral is interrupted, i.e if any unlinked protective device opened it would create a dangerous situation. No matter what kind of service head you have, it should contain a link rather than a fuse.

On single-phase service, until 1943 it was considered beneficial to fuse the neutral because it was not assumed that neutral was reliably earthed, so there could be fault conditions that a fuse in the line (live, as of 1943) would not protect against. But a change in the ESR1937 made it mandatory to keep the neutral solidly earthed, so the revision to the 11th edition recommended single-pole fusing instead.
 
Hi Polo Yesterday saw a really high tide but not as bad as the mainland but the south of the island caught the worst of the high tide and storm surge, me I stayed put with me beer
Pict
 
I came across many early service heads with fused neutrals. Originally the supply was DC two wire. The service heads had a glass panel for the rewireable fuse bridges.
 
On a 3-phase 4-wire service it was never correct to fuse the neutral and I have never seen it done.

Very true, nor have i, though i dare say it has occurred in the past. My fault for not reading the OP properly, totally missed the stated 3 phase bit!! lol!!
 
ive seen a few fuse blocks (tip out type)similar to theseFused Neutral 811series_200x200_190h - EletriciansForums.netwith steel links labelled neutral only (fusing a neutral here is against code as well)
and had to explain to the apprentices and production twits why the cant put fuses in them
 
your right of course, and once again another round of phone calls to get them out with the usuall " can I have the customer account number,the post code, can the engineer park at the premises, will he need a ladder, will the customer be present, are there any dogs at large, etc etc thats if I get through to engineering at all as they have changed all the numbers I had
Pict
had dealings with sp energy networks recently and they were great,mind you we have of road parking,a large dog and a ladder,so maybe that made a difference.lol
 

Reply to Fused Neutral in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net

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
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