Fused neutral on 3 phase farm property

[SW1970]

Hi folks, what began as changing some lights for a tenant in an outbuilding has become quite a nice project. The 3 phase origin and main panel is a mess and needs sorting. First concern is that the neutral appears to be fused. It may have had a solid link installed but can't determine. In these situations, is the best approach to find out supplier details from owner and contact DNO directly or ask owner to do it with my support? Many thanks, SW

 

[malcolmsanford]

If the head is that old to have a fusible neutral, and it is 3 phase, I would not be wanting to touch it unless under threat of death.

The ESQCR-2002 gave the DNO companies until 2013 to replace all fused neutrals and you may find that there is now just a link in it, but call the DNO about this and ask, chances are they will not know and will send someone to check it out for you

 

[vaughant]

I was wirking on a fault the other night in work (someone thought it was a good idea to run a 240v fan off a 110v socket,for years apparently!!!!) and in the plug there were fuses for both live and neutral which I've never seen before,the plug did look very old I must say.

 

[telectrix]

could be a 55-0-55, so could well have both line fused.

 

[Knobhead]

The main problem I can foresee is the awkward question “how do you know it’s fused?”

 

[SW1970]

Yep - getting details of supplier this afternoon to find out what the status is. It might be solid link but there's no signage about this.

 

[stevewilton]

For the gent who said a 110v supply had both supplys fused this is correct.
On a 110v supply you have two 55v live supplys either side of 0v thus requiring a double pole over current protection (as found on site temp transformers.)

 

[netblindpaul]

SW,
It is NOT the energy supplier you need to contact it is the DNO.
Unless one in the same.
The incoming cable & head are DNO property, it is the meter that belongs to the energy supplier, with the tails from the head to the meter being a bit of a grey area!
The DNO should discuss this with you directly (hopefully!) even though you are not the energy buyer as the financial side of things is not involved.

 

[SW1970]

Hi, thanks - yep - I use the term "supplier" casually.

 

[netblindpaul]

OK SW, that's fine, as long as you don't end up wasting your life away on the end of the phone to the energy provider who will no doubt have an offshore call centre, who in turn will have no idea what you are on about!

 

[SW1970]

If the head is that old to have a fusible neutral, and it is 3 phase, I would not be wanting to touch it unless under threat of death.

The ESQCR-2002 gave the DNO companies until 2013 to replace all fused neutrals and you may find that there is now just a link in it, but call the DNO about this and ask, chances are they will not know and will send someone to check it out for you

Spot on Malcolm, the DNO didn't know! They couldn't even confirm whether it is 3 phase. Goodness only knows how they can demonstrate conformance to ESQCR. Scary thing was I had to explain to the lad on the phone what a fused neutral was. He listened carefully and then booked a survey job in. So all in all a good outcome so far.

 

[nickblake]

good advice from the guys and getting it checked is the best option if a neutral goes down on a three phase supply then it can be disaster and cause a lot of damage