whose tails and how would you like it sir?

[No.15]

If tails from meter/ isolator to CU belong to the customer, is said customer required to notify supplier when having the length of the tails extended?

Would someone please explain the why, what and where of a switchfuse used when extending tails. Thank you.

 

[EasyFox]

Depends on how long the tails are to be extended by.
Call DNO & ask what max length of tails they will allow without switch fusing.
You'll need to call them anyway to arrange for a meter monkey to visit & pull service fuse, (you cant work live to extend the tails) while you work then refit the fuse.

Why:
Because in effect the tails become a submain & as such will require a cpc + ocpd suitably rated for the load length of submain & csa of cable.

WHAT:
Wylex 100 Amp SP&N Switchfuses
or something like this will do so long as the mcb is rated high enough
100 Amp Main Switch for Sentry Consumer Unit
50 Amp MK MCB
4 Way Insulated Enclosure

WHERE:
Ask nicely and DNO will let you put it in the meter cupboard.
Failing that at a length of meter tail that the DNO say is ok before a SF is required (normally 3mtrs)

 

[No.15]

Thank you for responding EasyFox, the lightbulb hasn't quite gone on in my head yet though. Would you mind following up with my questions below?

Why:
Because in effect the tails become a submain & as such will require a cpc + ocpd suitably rated for the load length of submain & csa of cable.

Why do the tails become a submain? If the tails were split, after the meter and isolator, for two CUs - are these now submains? [I think I'm not actually clued up on what a submain is - I had thought it was a distribution board coming from an mcb way in an upstream CU ]

If the switchfuse protects the length of tails between meter and CU, why is not having one for 3m tails ok, but not for say 15m tails?

Thank you.

 

[Spudnik]

The DNO are not responsible for the design of the installation so they require an over-current protective device to be fitted if tails exceed 3M to protect them.

So, basically, if you dont, they are well within their rights to cut off your supply as the above is usually a requirement for the supply of electricity to the premises.

 

[No.15]

ok, thanks for that Jason. I'll accept that that's the way it is, though if the tails are the customer's, then why are the DNO involved? If the DNO's supply cable went 15m further, do they make any adjustments to the fuse fitted?

As you can see, I've not quite got it Sorry.

 

[PAUL M]

ok, thanks for that Jason. I'll accept that that's the way it is, though if the tails are the customer's, then why are the DNO involved? If the DNO's supply cable went 15m further, do they make any adjustments to the fuse fitted?

As you can see, I've not quite got it Sorry.

I think you may be trying to look into it too deeply.

 

[No.15]

I think you may be trying to look into it too deeply.

You're right, I'll let go of it ..time to find another bone to worry.

I keep six honest serving-men
(They taught me all I knew);
Their names are What and Why and When
And How and Where and Who.
...la la lalala la...
But different folk have different views;

 

[danzor]

more length is better

 

[wayne]

more length is better

usually its length depth and time....sorry are we off track??

 

[No.15]

hmmm, size does matter after all

You've got my dog barking all round the house with me laughing out loud!

 

[Spudnik]

though if the tails are the customer's, then why are the DNO involved?

Because it is THEIR equipment that the tails are connected to.

 

[Shakey]

Because it is THEIR equipment that the tails are connected to.

but are they?

the tails are connected to the meter, and that is not the DNO's, that is your electricity suppliers, your DNO's property ends at the incoming fuse

 

[Spudnik]

but are they?

the tails are connected to the meter, and that is not the DNO's, that is your electricity suppliers, your DNO's property ends at the incoming fuse

Thats correct, however, the DNO own the supplying cable, fuse etc (the important bit). the meter is only to monitor usage, not to provide any fault protection.

Therefore, they have the final say on how you connect your installation to THEIR supply.

Some DNO's will not connect a new supply without seeing an install certificate from an NICEIC or ECA registered member.

You are thinking far too much about this!!!

 

[lost-sole]

my mrs says that i need to increase my cross sectional area!!!

 

[wayne]

my mrs says that i need to increase my cross sectional area!!!

she said the same thing to me

 

[spark-doctor]

Thats correct, however, the DNO own the supplying cable, fuse etc (the important bit). the meter is only to monitor usage, not to provide any fault protection.

Therefore, they have the final say on how you connect your installation to THEIR supply.

Some DNO's will not connect a new supply without seeing an install certificate from an NICEIC or ECA registered member.

You are thinking far too much about this!!!

To clarify

1) The DNO own and maintain the supply cable and cutout/fuse holder
2) The electric company who you buy your electric from own and maintain the cables from the cutout to the meter and the meter.
3) The home owner is responsible for the cables from the meter to the consumer unit. This is why some suppliers charge if you need to upgrade from 16 to 25mm tails.
4) There is no obligation for a supply company to fit a isolator, BUT almost all will fit one on new builds or on request. Some charge, some don't.
5) The DNO or the supply company have the legal right under the ESQCR to terminate your supply if they HAVE REASON TO BELIEVE that your installation does not comply with the currant regulations.
6) The DNO is responsible for determining the route, length & CSA of the meter tails. Because different DNO's have different ideas on how things should be done, it is difficult to get a conscious of opinion.

I recently went to 5 new builds with the meters outside in box's. None had isolators and the meter was 5 meters from the cu.