Guys,

Apparantly there is a chart that meter installers of larger supplies use to check what fuses they can install with certain sizes of meter tails.

Can anyone provide this chart for me ? - I think BOD has a copy?

Regards,
Alex.

If the chart isn't available, can someone tell me if they accept 95mm2 (1.5m run) inside 6x6 trunking with 50mm main earth & 25mm bonding.

Thanks.

You are correct in your sizing, assuming you are talking about
240 amps/phase fusing.
Bare in mind that this size of 3phase supply reqs an external loop impedance of 0.20ohms, or less.
Any further info please ask, and I will calculate it for you.
By the way I know of no Meter mans chart, perhaps some of the others have one, but this calculation is correct.

Alex,

I've got one, PM me your email address.

My copy is the siemens version, but I think they are all the same.

Stu

Many thanks for the reply, I forgot to state the fuse rating - 200A P/Ph I would take it the DNO would ensure the EFLI was <0.20 ohms? Am I correct in sizing 25mm equipotential bonding?

Edited: 09 August 2010 at 05:49 PM by Alexg

If it is a 200amp/phase load 70mm, rather than 95mm will do.
as regards bonding, its still 25mm.
However, as you have now dropped a size to 70mm,
35mm earthing lead willdo,mechanically protected, trunking to CT box.
course, if youve already the cable......................! sorry!

Many thanks PME.

I think I did originally spec 70mm but was then told this "meter mans chart" stated it had to be 95mm in order for them to connect...