Supply question

[Cristafar]

Hi, just looking for advice. Ive been to look at a Fire alarm install job. While checking where i will take my supply from. 3 phase sub board, i wanted to see where its supplied from and origin etc. It turns out the Electrician has wired the sub mains board from an old redudant 3 phase power line. Hes run 16mm 6181y protected by a RCD. cable runs outside up the pole and connected to the lines.
Then at the sub board there is is 4 core 10mm swa connected to the lines down to the sub mains board.
Surely this is a big No No and needs disconnecting.

 

[James]

Not easy to figure out what is going on here,
what exactly is your concern?
is the cable underrated for the protection,
is there a lack of earth?
is the cable (redundant? or now in use) in poor condition?

 

[westward10]

What is a power line?

 

[Cristafar]

Not easy to figure out what is going on here,
what exactly is your concern?
is the cable underrated for the protection,
is there a lack of earth?
is the cable (redundant? or now in use) in poor condition?

What is a power line?

Overhead power line.

 

[Cristafar]

Not easy to figure out what is going on here,
what exactly is your concern?
is the cable underrated for the protection,
is there a lack of earth?
is the cable (redundant? or now in use) in poor condition?

The fact hes connected to a redudant over head power line?

 

[James]

If it is bare wires, separated by air. then assuming it is in good condition, I cant see an issue unless it could come in to contact with something.
have a look at 417.3
have a think, have you identified a risk or a deviation from the regs.
or is it just something you have not seen before and are thinking it must be wrong because it is unusual?

 

[westward10]

What is an overhead power line?
I'm sorry but I have no idea what this is specific to.

 

[Cristafar]

If it is bare wires, separated by air. then assuming it is in good condition, I cant see an issue unless it could come in to contact with something.
have a look at 417.3

Will do thanks. The manager did say , a tipper truck did catch it once, even though he told him hes close, he said no it will be fine. And yep apparently caught one of the lines .

 

[Cristafar]

What is an overhead power line?
I'm sorry but I have no idea what this is specific to.

 

[Cristafar]

If it is bare wires, separated by air. then assuming it is in good condition, I cant see an issue unless it could come in to contact with something.
have a look at 417.3
have a think, have you identified a risk or a deviation from the regs.
or is it just something you have not seen before and are thinking it must be wrong because it is unusual?

Yes not seen before and wondered if was allowed. Poles may belong to DNO etc. So just wondered if it was allowed . That is all .

 

[Cristafar]

If it is bare wires, separated by air. then assuming it is in good condition, I cant see an issue unless it could come in to contact with something.
have a look at 417.3
have a think, have you identified a risk or a deviation from the regs.
or is it just something you have not seen before and are thinking it must be wrong because it is unusual?

Just read 417.3 . Puts my mind at rest.

 

[westward10]

They've supplied a distribution board from some overhead hv distribution power lines?

 

[Cristafar]

They've supplied a distribution board from some overhead hv distribution power lines?

LV redundant lines , they made live again , by running

They've supplied a distribution board from some overhead hv distribution power lines?

16mm 6181y cables up to the lines.

 

[DPG]

Have you got any photos? I'm picturing something really horrific here.

 

[Cristafar]

Have you got any photos? I'm picturing something really horrific here.

No sorry, but its just a pole with 5 horizontal lines 3ph N E . Which go across to, two other poles , between old barns , then a phase dropped down to one board and 3 phase supply dropped down to another fused board , SWA used from the lines down to the boards. All protected by 32amp 60898 with linked 61009 RCB0.

 

[westward10]

If a fork lift has already hit it then placing out of reach is somewhat tenuous and a means of protection I have never resorted to in 40 odd years.

 

[davesparks]

Years ago it was not uncommon to install private overhead lines for distribution circuits in places like farms, caravan parks, industrial sites.

It may be that these days it is no longer suitable for that site and it could attract a C2 code should an EICR be carried out. But this shouldn't have any bearing on you installing a fire alarm.

 

[Rockingit]

If a fork lift has already hit it then placing out of reach is somewhat tenuous and a means of protection I have never resorted to in 40 odd years.

Farm lads around here run into LV overheads all the time, seems ‘placing out of reach’ was never really considered with 20’ flail mowers in mind!!

 

[DefyG]

I'm picturing LV overhead lines feeding a 3ph DB in a barn (BS 6181's) and in turn from there feeding another 3ph DB.

just a pole with 5 horizontal lines 3ph N E . Which go across to, two other poles , between old barns , then a phase dropped down to one board and 3 phase supply dropped down to another fused board , SWA used from the lines down to the boards. All protected by 32amp 60898 with linked 61009 RCB0.

And SWA cables feeding other 'boards' !! from the overhead lines ........ but where is the metering unless it is a private distribution network and metering is at source/intake? and whole lot protected by 32A mcb?

 

[SparkySy]

This sounds to me like Barns with the customers overhead connections after the intake and metering.
There used to be many like this near me, with uninsulated conductors running on poles between the Barns.
Most of them now have been changed to underground supplies due to the exact problem above.
As tractors and equipment has got bigger they have become more likely to be struck by such equipment and as a result installed in a much safer way!

 

[davesparks]

And SWA cables feeding other 'boards' !! from the overhead lines ........ but where is the metering unless it is a private distribution network and metering is at source/intake? and whole lot protected by 32A mcb?

Yes, relatively common, especially in rural areas, once upon a time.
The bare overhead lines would be hard-drawn copper and supported on porcelain insulators.
PILC, SWA or insulated and sheathed tails would be connected to them via line taps wherever required.

I suspect this type of distribution is the reason, or at least one of the reasons, that 'placing out of reach' is still in the regulations as a method of protection.
Much like BS3036 fuses and PEN conductors, you can't just remove the regulations that support them because they still exist in the real world despite being out dated.