Hi guys just going to start new job meter has been moved by dno what is the max length of meter tails do i work it out the same as volt drop on pvc cables/the meter is now outside new extension and the consumer unit will be in old kitchen about 15meters away
Confirming what some of the other guys have said... Meter tails are just another circuit... From Meter to CU...
Not much different to a large installation or say an agricultural installation.. where supply comes to one building..
and another separate building needs its own Cu distribution...
You just stick in a suitable sub-main, meeting certain requirements to ensure..
Mechanical protection,
Isolation,
Fuse protection,
Volt drop etc.. etc..
Within a house, meter tails with adequate sheathing for mechanical protection
and possibly Trunking or conduit if a longer or hazardous run due to external influences where the cables will be run..
I think the 3m bit comes from general guidance about when you need a separate switch to isolate the tails, not just the main fuse.. But think this is just good practice, not a reg.
The only bits I could quickly find in the big book is...
537.1.4 A main linked switch or linked circuit breaker shall be provided as nears as practicable to the origin of every installation as a means of switching the supply on load and as a means of isolation.
A mains switch intended for operation by ordinary persons, e.g. of a household or similar installation, shall interrupt both live conductors of a single phase supply.
which is a combination of old regs "460-01-02" & "476-01-03"
old regs also had this reg, 476-01-02,
where the last sentence had significance upon the meter tails