Safe Zones

[Jetset]

Does anyone know when Safe Zones for cables were introduced?

I’ve opened a stud wall for pluming in bathroom and cables for the adjoining room are nowhere near complying. They’re all over the place.

Property was built about 1984.

 

[ericmark]

1991 16th edition came out, and 1992 it became BS7671 until that time although there were regulations they we kept in managers office and rarely did the electrician as such get access to them, it was all word of mouth, the only 14th edition was more like the guide to the editions that we see today, with examples of how it should be done.

I think I remember seeing the safe zones in the 14th edition, but they were simply not followed in the same way as they are today. I went to work abroad in 1980, and at that point very rare did anyone refer to regulations, I returned early 90's and all you heard was 16th says this, or 16th says that. And we started to get courses and certificates to say we could read a book, in early days some were in house from the collages not city and guilds as to when C&G 2381 came out I am not sure?

In 2004 there was a second push for electricians to get C&G 2381, 2391 and 2377 certificates, this was when Part P first came out, at this point the floating between commercial and domestic became much harder, already two organisations that issued some certificate to say you were an electrician which resulted in my being an advanced electrician on commercial sites, but not recognised on domestic sites.

Commercial it was tray, trunking, conduit, and other methods of containment, including being able to step back from a panel, and unwritten rules like one hole is for one wire, the idea of shoving over 3 wires into a terminal was a no no. And since wires were not concealed in walls, we did not need to know the rules about them. However knowing how to read a PLC program or test a solenoid was standard. We called the domestic electrician house bashers and were in the 90's considered as the low end of the trade, and some thing you did while between proper jobs.

So in the 90's it was common for electricians to swap, commercial to domestic so very likely the electrician did not have the skills of today's domestic electricians, and of course today with home automation on the increase the domestic electrician also needs to know how quite complex systems are programmed no longer is the Y plan central heating the most technical job they get. Today very few swap between commercial and domestic, they both need different skills, but in 1984 it was common for house wiring to be done by semi-skilled guys with maybe if you were lucky one electrician popping in every so often to see if all was OK.

We did however have the thought police!!

 

[Jetset]

1991 16th edition came out, and 1992 it became BS7671 until that time although there were regulations they we kept in managers office and rarely did the electrician as such get access to them, it was all word of mouth, the only 14th edition was more like the guide to the editions that we see today, with examples of how it should be done.

I think I remember seeing the safe zones in the 14th edition, but they were simply not followed in the same way as they are today. I went to work abroad in 1980, and at that point very rare did anyone refer to regulations, I returned early 90's and all you heard was 16th says this, or 16th says that. And we started to get courses and certificates to say we could read a book, in early days some were in house from the collages not city and guilds as to when C&G 2381 came out I am not sure?

In 2004 there was a second push for electricians to get C&G 2381, 2391 and 2377 certificates, this was when Part P first came out, at this point the floating between commercial and domestic became much harder, already two organisations that issued some certificate to say you were an electrician which resulted in my being an advanced electrician on commercial sites, but not recognised on domestic sites.

Commercial it was tray, trunking, conduit, and other methods of containment, including being able to step back from a panel, and unwritten rules like one hole is for one wire, the idea of shoving over 3 wires into a terminal was a no no. And since wires were not concealed in walls, we did not need to know the rules about them. However knowing how to read a PLC program or test a solenoid was standard. We called the domestic electrician house bashers and were in the 90's considered as the low end of the trade, and some thing you did while between proper jobs.

So in the 90's it was common for electricians to swap, commercial to domestic so very likely the electrician did not have the skills of today's domestic electricians, and of course today with home automation on the increase the domestic electrician also needs to know how quite complex systems are programmed no longer is the Y plan central heating the most technical job they get. Today very few swap between commercial and domestic, they both need different skills, but in 1984 it was common for house wiring to be done by semi-skilled guys with maybe if you were lucky one electrician popping in every so often to see if all was OK.

We did however have the thought police!!

Thank you very much. Great reply!

This place was 1980s so another decade back than what you describe, of course. Cheers!

 

[sparkwright]

Does anyone know when Safe Zones for cables were introduced?

I’ve opened a stud wall for pluming in bathroom and cables for the adjoining room are nowhere near complying. They’re all over the place.

Property was built about 1984.

Even today, a lot of electricians out there seem to think that safe zones don't apply to stud walls. They seem to think that just bt drilling through the centre of a stud, the cable will be 'nearly' 50mm from the finished surface.

All wrong of course, but I do see a lot of it, and it can nearly always be avoided with some thought.

 

[JohnW2]

Even today, a lot of electricians out there seem to think that safe zones don't apply to stud walls. They seem to think that just bt drilling through the centre of a stud, the cable will be 'nearly' 50mm from the finished surface.

... and not just that. When cables are 'fished' through stud walls, they appear (at least in my experience) rarely to be taught enough between known points for one to have any certain idea as to what precise path the cable takes within the wall.

Kind Regards, John

 

[ericmark]

... and not just that. When cables are 'fished' through stud walls, they appear (at least in my experience) rarely to be taught enough between known points for one to have any certain idea as to what precise path the cable takes within the wall.

Kind Regards, John

Seem to remember that was the Emma Shaw case where the cable looped and was hit by the plasterer, which caused the metal studding to become live, and the plumber forgot to glue the tun dish and the water ejected from the hot water system wet the floor and connected floor to live, so when Emma touched the stop cock she got a lethal shock.

It should have been highlighted before that point, however the semi skilled guy testing when he got an odd result fudged up some readings in the mess hut, so the foreman was unaware anything was wrong, so never even visited the site.

The foreman was found guilty, seems he should not have used semi skilled labour to do the testing.

It was to me a surprising result. It does point out how vital inspection and testing is, and it points to finding a house holder guilty of manslaughter if he fails to have the inspection done at recommended times.

In real terms it could not happen today, the RCD would trip first, but there were 5 separate people all made errors to cause the death. And the guy who allowed slack cable to drupe into path of plasterers fixing was not the guy found guilty.

 

[securespark]

Regarding the 14th Ed. and cables in safe zones, so far I can only find this catch-all reg:

B.25 All conductors and cables shall be adequately protected against any risk of mechanical damage to which they may be liable in normal conditions of service.

 

[crystal ball]

Seem to remember that was the Emma Shaw case where the cable looped and was hit by the plasterer, which caused the metal studding to become live, and the plumber forgot to glue the tun dish and the water ejected from the hot water system wet the floor and connected floor to live, so when Emma touched the stop cock she got a lethal shock.

It should have been highlighted before that point, however the semi skilled guy testing when he got an odd result fudged up some readings in the mess hut, so the foreman was unaware anything was wrong, so never even visited the site.

The foreman was found guilty, seems he should not have used semi skilled labour to do the testing.

It was to me a surprising result. It does point out how vital inspection and testing is, and it points to finding a house holder guilty of manslaughter if he fails to have the inspection done at recommended times.

In real terms it could not happen today, the RCD would trip first, but there were 5 separate people all made errors to cause the death. And the guy who allowed slack cable to drupe into path of plasterers fixing was not the guy found guilty.

Unlikely to happen as long as the RCD is working correctly

 

[ericmark]

Unlikely to happen as long as the RCD is working correctly

I did say "In real terms it could not happen today, the RCD would trip first". I fitted twin RCD's in about 1998 when my 14 year old son passed his RAE mainly to protect him.

However when we moved in here earlier this year, the main house was still on rewireable fuses, and flat under the house only half the circuits were RCD protected, so 14 circuits and only around 4 on RCD. Now all RCD.

In my old house in spite of all RCD I was knocked to the floor when I hacksawed through a horizontal cable to the light switch, I had not expected anyone to take a cable around 4 right angle corners, but they did, I would say once you reach a corner the safe zone ends, clearly a view not taken by my father-in-law who wired the extension.

 

[securespark]

Does anyone know when Safe Zones for cables were introduced?

As per my previous post, I can't find any mention of specific safe zones in the 14th Edition (1966-1981) save for the catch-all reg about installing cables so they don't get damaged.
However, in the 15th Ed. (1981-1991) safe zones are included, albeit without that name.

From the 15th Edition:

523-20(a) Where a cable is to be concealed within a wall or partition its method of erection shall comply with Regulation 523-20(b) or 523-20(c) or its construction shall comply with Regulation 523-20(d), as appropriate.

523-20(b) The cable shall be installed within 150mm of the top of the wall or partition or within 150mm of an angle formed by two adjoining walls or partitions.

523-20(c) Where the cable is connected to a point or accessory on the wall or partition, the cable may be installed outside the zones permitted by Regulation 523-20(b) only in a straight run, either horizontally or vertically from the point or accessory.

523-20(d) Where compliance with Regulation 523-20(b) or 523-20(c) is impractical, the cable shall be of a type incorporating an earthed metallic covering complying with the requirements of these Regulations for a protective conductor of the circuit concerned, or the cable shall be enclosed in earthed conduit, trunking or ducting satisfying the requirements of these Regulations for a protective conductor.


The last one details what to do to protect the cable if you cannot run it in the safe zones.

However, the 15th Edition's layout was based on the IEC regulations and as such many contractors found it confusing and hard to understand. Phasing out the 14th Ed was stalled until 1982, then again until the beginning of 1985. In effect, between 1981 and 1985, electrical work could be carried out to either the 14th or the 15th Edition.

So.....if you find work done in houses built pre-1985, it is possible to find cables outside of safe zones. However, a good installer should have followed regulation
B.25 from the 14th Edition: All conductors and cables shall be adequately protected against any risk of mechanical damage to which they may be liable in normal conditions of service.

 

[crystal ball]

I remember whilst working for NORWEB 85-90 we had a refresher on the "new" regs and that was a major part of it