Phase Identification

[Wontdothatagain]

We are instructed to alter this arrangement if we find it. We split one of the outgoing tails from the meter, usually L1 and feed the potential from there. The neutral can still come from the head. If it is feeding a load, we split the neutral as well.

There have been instances where the meter op has got "confused" and fed the load from the fuses as well.

 

[Wontdothatagain]

The arrangements has remained as you see through at least two meter changes.

Your next meter will probably be a "Smart Meter" so you wont need a time clock anyway

 

[JohnW2]

We are instructed to alter this arrangement if we find it. We split one of the outgoing tails from the meter, usually L1 and feed the potential from there. The neutral can still come from the head. If it is feeding a load, we split the neutral as well.

Interesting. I thought that the meter operator's responsibility/ownership ceased, and the consumer's started, at the output terminals of the meter. Are you saying that you would instal a (sealed) henley block on the consumer's side of the meter?

.... and do I take it that you would wire the clock in sufficiently heavy cable to be adequately protected (presumably per BS7671, given that it's 'post-meter') by the DNO's fuse?

Kind Regards, John.

 

[JohnW2]

Your next meter will probably be a "Smart Meter" so you wont need a time clock anyway

Yes, that recently occurred to me!

Kind Regards, John.

 

[Wontdothatagain]

Are you saying that you would instal a (sealed) henley block on the consumer's side of the meter?

Correct, just because the tails dont belong to us does not mean that we dont have control over them, the same as a DNO does not own the meter but they do have control over equipment connected to the servise head and are allowed to break the seals and make alterations if they se fit.

and do I take it that you would wire the clock in sufficiently heavy cable to be adequately protected (presumably per BS7671, given that it's 'post-meter') by the DNO's fuse?

No we would wire it in 2.5 double insulated singles

 

[JohnW2]

Correct, just because the tails dont belong to us does not mean that we dont have control over them, the same as a DNO does not own the meter but they do have control over equipment connected to the servise head and are allowed to break the seals and make alterations if they se fit.

Fair enough.

and do I take it that you would wire the clock in sufficiently heavy cable to be adequately protected (presumably per BS7671, given that it's 'post-meter') by the DNO's fuse?

No we would wire it in 2.5 double insulated singles

I wonder why I thought you were probably going to say that? ... As we know, it's not a case of 'one set of regulations fits all'

Kind Regards, John.

 

[Wontdothatagain]

We do not work to BS7671, we are under the ESQCR

 

[westie101]

Missed all of this one!

Use of green as a phase colour is pre-nationalisation and could often be restricted to a particular town (council electricity dept) it was often easier to continue using these colours than visit and change each property.
We have pre-WW2 cables that have green/yellow as a phase (what is now L2) and blue as the neutral. The others are red and green paper!
We have a log of all unusual items (or mark it on our records), similarly we have to prove phases and neutral before connecting customers.

Phase rotation historically was never always R, Y/W/G, B. Again in most cases councils adopted their own directions.

The use of tails protected by the cut-out fuse is a thorny one. Some suppliers (in opposition to DNO rules) do fuse them down these are often found when off-peak heating switches on and the fuse then blows.
(though we do suspect some think that BS7671 applies to DNO equipment and are shocked when the realities are pointed out)
(the latest being a threat of defecting a customer installation because of the size of our earth cable between our cable sheath and the MET. He appeared shocked when I told him it does not form part of the installation but is part of the supply network!)

 

[JohnW2]

... As we know, it's not a case of 'one set of regulations fits all'

We do not work to BS7671, we are under the ESQCR

Quite!

Kind Regards, John.

 

[JohnW2]

Use of green as a phase colour is pre-nationalisation and could often be restricted to a particular town (council electricity dept) it was often easier to continue using these colours than visit and change each property.

Thanks. That makes sense. As I illustrated, the only sense in which the Red/Blue/Green persists in my installation is in those 3 discs - any idea what sort of vintatge they'd be?

Phase rotation historically was never always R, Y/W/G, B. Again in most cases councils adopted their own directions.

Thanks again.

The use of tails protected by the cut-out fuse is a thorny one. Some suppliers (in opposition to DNO rules) do fuse them down these are often found when off-peak heating switches on and the fuse then blows.

I see! Although I suppose the probability of a major fault occuring in the clock is low, I imagine that wontdothatagain's 2.5mm² singles might well melt before the cutout fuse operated, but maybe your regs just regard such cables as 'fuses'

Kind Regards, John.

 

[westie101]

I couldn't really give a vintage for the discs but they were probably fitted when the supply was first installed or uprated to 3 phase

I see! Although I suppose the probability of a major fault occuring in the clock is low

If I recall, time clocks are protected by an internal fuse so the issue is the tails only!
If we were burning houses down at regular intervals there would be an issue!

It's fair to say that there is, generally, a huge void in the approach to protective devices on both sides of the cut-out. It is rare for us to fuse to protect for excessive load (we do in some cases) but mainly to protect in case of faults occurring).
On the network we accept the risk of burning out lengths of cable in some conditions (face it will a 400A or even a 630A fuse protect the 25mm service cable into a property?)

 

[JohnW2]

I couldn't really give a vintage for the discs but they were probably fitted when the supply was first installed or uprated to 3 phase

That makes sense. I know that there was a 3-phase supply in 1950 (Estate-agent-talk hasn't changed much over the decades - we have an auction catalogue from 1950 which indicates that the property 'benefitted from a 3-phase electricity suppy' - and also a (long since gone) 300 gallon water tank!), and historical documents seem to suggest that there was an earlier point in time when the property (split up a bit, by that 1950 auction) was the only one in the village (right on the edge of the village) with an electricity supply.

If I recall, time clocks are protected by an internal fuse so the issue is the tails only! If we were burning houses down at regular intervals there would be an issue!

If you got found out

It's fair to say that there is, generally, a huge void in the approach to protective devices on both sides of the cut-out.

Indeed, having previously not really known anything much about your side of the cutout, that's one of the ('surprising') things I've discovered by participation in this forum.

Kind Regards, John.