concentric cable ???

[Guest55]

BTW Biff 35mm²Al/Cu is the usual now.

not for 100A single phase it isnt.
not unless the nearest mains is 100 or more yards away.

 

[davesparks]

In this area it is always 35mm solid Al core with CU outer conductor for 100A SP

 

[Knobhead]

I borrowed some from down a hole. Definitely 35mmAlCu.

 

[Rockingit]

Around here it's 16mm.

 

[Engineer54]

To be honest, i've only ever seen 35mm concentric being used by the DNO for domestic, small commercial installations. They tend to purchase a one size fits all for these installations, and as stated 35mm aluminium is the going size for a 100A supply... Though looking at the cable dia, it could be easily be excused for looking like a 16mm cable... lol!!

 

[Rockingit]

No, around here, which is WPD, it's definitely 16mm Al with Cu spiral. I've got some, and I've also had to work with it on DNO kit that's transferred to private (don't ask).

 

[Engineer54]

No, around here, which is WPD, it's definitely 16mm Al with Cu spiral. I've got some, and I've also had to work with it on DNO kit that's transferred to private (don't ask).

Well i wouldn't feel happy with a 16mm Ally concentric or split concentric cable with a 100A BS 88 protecting it. A 60A fuse i probably wouldn't be too phased about!! lol!!

 

[Rockingit]

Maybe that's also why they only fit 80A fuses, who knows. They seem to make it up as they go along anyway!!

 

[mechelec]

No, around here, which is WPD, it's definitely 16mm Al with Cu spiral. I've got some, and I've also had to work with it on DNO kit that's transferred to private (don't ask).

WPD standard for single phase TNCS supplies up to 100 A is 25 mm hybrid with aluminium core phase conductor with copper concentric neutrals.

 

[mechelec]

Well i wouldn't feel happy with a 16mm Ally concentric or split concentric cable with a 100A BS 88 protecting it. A 60A fuse i probably wouldn't be too phased about!! lol!!

It could be 400A fuses in the sub station "protecting the cable" The assumption is the service cable will burn open circuit in the event of a fault. Substation fuses do not protect cables they are there to grade with the HV protection for the local TX.

 

[davesparks]

The cutout fuse provides overcurrent protection

 

[Guest77]

just curious lol

Not Bi curious I hope chuckle

 

[Knobhead]

The cutout fuse provides overcurrent protection

For the installation not the service cable.

 

[Engineer54]

It could be 400A fuses in the sub station "protecting the cable" The assumption is the service cable will burn open circuit in the event of a fault. Substation fuses do not protect cables they are there to grade with the HV protection for the local TX.

Agree, i am aware of the philosophy behind the DNO LV fuse grading with the MV protection of local TX subs. But i still wouldn't be happy with a 16mm AU conductor supplying 100A service fuse. But then i wouldn't use AU cables at any level!! lol!!

 

[davesparks]

For the installation not the service cable.

I thought it did for the service cable?

 

[Knobhead]

Agree, i am aware of the philosophy behind the DNO LV fuse grading with the MV protection of local TX subs. But i still wouldn't be happy with a 16mm AU conductor supplying 100A service fuse. But then i wouldn't use AU cables at any level!! lol!!

I’d like to a fly onthe wall when you tell the DNO you’re not happy with the cable they deign suitable for your supply.

I’ll admit I don’t like aluminium cable.
That is until it comes to transformer tails, 600mm[SUP]2[/SUP] 4 sector solidal dresses beautifully into the terminals, once in place it doesn’t need as much bracing. OK it’s a pig if you don’t know what you’re doing with it.

 

[Knobhead]

I thought it did for the service cable?

The OCPD is back at the substation or feeder pillar. Anything up to 630A so as meclec said, the service cable should blow clear. It’s a bugger when it doesn’t and the breach joint blows.

The sphincter is twitching when you put one of the old “J” type feeder fuses in live. The new SAIF pillars are a doddle to work on live.


This is a SAIF pillar

 

[mechelec]

Quote "The OCPD is back at the substation or feeder pillar. Anything up to 630A so as meclec said, the service cable should blow clear. It’s a bugger when it doesn’t and the breach joint blows.


The sphincter is twitching when you put one of the old “J” type feeder fuses in live. The new SAIF pillars are a doddle to work on live."

You know about it when you replace a fuse on an old open frame LV pillar and pick up a big load. Plenty of contact grease on it and slam it in.
Lucy aculock same principal as Schneider SAIF much safer systems but not as good access for the test lamp.

 

[Richard Burns]

The OCPD is back at the substation or feeder pillar. Anything up to 630A so as meclec said, the service cable should blow clear. It’s a bugger when it doesn’t and the breach joint blows.

The sphincter is twitching when you put one of the old “J” type feeder fuses in live. The new SAIF pillars are a doddle to work on live.


This is a SAIF pillar

That picture is weird when you scroll up and down, it looks like it is coming out the page!