Two Circuits feeding 2G switch

[D Skelton]

Ok so imagine this scenario, commercial premises, sub DB 1 has a circuit feeding a control panel, now within that control panel is circuitry also fed by sub DB 2 which is located on the other side of the building.

I reckon less people would argue with me if I were to say a sticker would be needed in this situation on the control panel warning of the two different supplies from two different locations, even though the whole installation can be isolated at the main switchfuse before the busbar chamber.

Exactly the same scenario here, just exaggerated. And for the record, I take the meaning of the word 'supply' in this scenario to mean; supplies to that individual piece of equipment.

 

[Engineer54]

Some of our multi gang grid switch plates for large area switching can have anything up to 6 MCB's supplying these multiple circuits. We do mark/identify those supply/feed cables mind, with DB and circuit number. Will also generally be arranged to be on the same phase too!!


Certainly never been a No, No since i've been in the game, ....as already stated, virtually every two or more storey house in the UK will have this arrangement for landing and stairs lighting switches at both up and downstairs switch positions.

 

[D Skelton]

Don't forget that Uo does not exceed 230V.

I'm well aware of this, the label is there for anyone who might open it up expecting to only find 230V

 

[D Skelton]

Certainly never been a No, No since i've been in the game

Read what I said again mate, this is the bit everyone seems to be jumping on without reading fully:

"It is technically a no no to feed an item of equipment with more than one supply without a warning label"

 

[Guest55]

Ok so imagine this scenario, commercial premises, sub DB 1 has a circuit feeding a control panel, now within that control panel is circuitry also fed by sub DB 2 which is located on the other side of the building.

I reckon less people would argue with me if I were to say a sticker would be needed in this situation on the control panel warning of the two different supplies from two different locations, even though the whole installation can be isolated at the main switchfuse before the busbar chamber.

Exactly the same scenario here, just exaggerated. And for the record, I take the meaning of the word 'supply' in this scenario to mean; supplies to that individual piece of equipment.

fancyful thinking & completely different.
what you have there is 2 supplies from different sources & locations , not the same as multiple circuits at 1 switch point in a single phase domestic installation with only 1 CU.

at least bite at bit , im bored ;-)

 

[D Skelton]

fancyful thinking & completely different.
what you have there is 2 supplies from different sources & locations , not the same as multiple circuits (supplies) at 1 switch point in a single phase domestic installation with (from) only 1 CU.

Not at all different, the 'source' of the supplies comes from the same place! The main switch

Of course it is extreme compared to a domestic situation, but the theory is still the same. Two different supplies to one item of equipment. It is clear as mud in the regs; A warning label must be placed. I guess the only grey area quite rightly pointed out is the definition of 'supply', but my interpretation of that has already been made clear, as would it seem has yours considering your agreement with my last example!

at least bite at bit , im bored ;-)

Nothing to bite at mate lol, it is an interesting debate so no need to throw my toys out of the pram haha

 

[Risteard]

I'm well aware of this, the label is there for anyone who might open it up expecting to only find 230V

But where does BS 7671:2008 (2013) require a warning label in this scenario, bearing in mind that Uo does not exceed 230V?

 

[Guest55]

hmmm , if you say so.
all sounds a bit wishy washy to me.
and i aint agreeing with jack sh*t so dont get cute.

;-)

 

[D Skelton]

But where does BS 7671:2008 (2013) require a warning label in this scenario, bearing in mind that Uo does not exceed 230V?

On this I stand corrected, I thought 514.10.1 was for voltages in general exceeding 230V, not specifically Uo

 

[D Skelton]

all sounds a bit wishy washy to me.

Wishy washy my backside!

 

[Guest55]

On this I stand corrected, I thought 514.10.1 was for voltages in general exceeding 230V, not specifically Uo

whats this ???
surely not an admission of error ??

cracks have appeared in your argument and it has been logged for future reference and prosperity.

:-D

 

[D Skelton]

whats this ???
surely not an admission of error ??

cracks have appeared in your argument and it has been logged for future reference and prosperity.

:-D

Haha, I'm not too proud to admit when I am wrong, unlike many others on here! (no names mentioned lol) Thanks to Risteard I actually opened my book and re-read the regulation, which if I was dogmatic in my views I wouldn't have done, and I'd be a worse electrician for it.

I remain steadfast on my interpretation of the word 'supply' however

 

[Guest55]

i wouldnt sweat it , i've been making it up as i go along for years lol.

 

[SPARTYKUS]

i wouldnt sweat it , i've been making it up as i go along for years lol.

Well, with all this talk of conductors, and lines, I have been under the impression this was a train enthusiasts forum.

Imagine, as a train driver, how embarrassed I now find myself.

 

[Geordie Spark]

Wishy washy my backside!

Is that a request or an order??