History or when did it happen?

[ericmark]

1. Combine the separate lighting and power meters into one.

2. Use earths with supplies (requirement under regulations)

3. Use earths on lights 1966 I think?

4. Use of ELCB (requirement under regulations for TT supply)

5. Drop the use of ELCB-v

6. Change from L = live to L = line. (If it ever meant live?)

7. Require RCD on out door supplies.

8. Require RCD on near all supplies 2008.

9. Distance socket to sink (if ever)

10. Distance isolator to cooker (if ever)

11. Change from 240 to 230 volt.

12. Change flex colours

13. Change fixed wiring colours

14. Change from 7/0.012 to 2.5mm²

15. Change from all copper pins 13A plug to insulated top section.

16. Change in earth bond to all metal

17. Change back so metal window frames don’t require an earth.

18. Change removing some earth bonding in bathrooms 2008

 

[securespark]

1. I would guess at the late 50's sometime?

2. Supply cables? All I can say is that on the first estate in Manchester to be built with electricity, the cables were TN-S.

I think it's a regional thing, though. In both rural and urban Staffs, there are both subterranean and overhead TT supplies, many of which have been converted but many not.

3. 1966 14th Ed.

4. 14th Ed. makes no specific mention of TT supplies, but says that if the earth fault current does not exceed 3x rating of a 3036 or cartridge fuse having a fusing factor exceeding 1.5 or 2.4 x the rating of a cartridge fuse not exceeding 1.5 FF or 1.5 x the tripping current of CB, then earth leakage protection shall be provided. One option is a current-operated ELCB but this must be used only where the product of its operating current and the EFLI does not exceed 40. The consumer's earthing terminal must be connected to a suitable earth electrode.

5. Deleted from the 15th Ed. in the January 1985 amendments.

6. Sometime in the 16th, IIRC. In the 15th, the definition of live included neutral, but not PEN conductors. However, "line" is not mentioned.

7. Not sure, but I remember working on New Builds in 1984 that had an sRCD near the front door and one near the back door.

8. In with 17th.

9. AFAIK, not ever in regs but introduced in building regs as 300mm minimum.
Regs stipulate equipment should be suited to its environment.

10. 6 ft. in 14th, 2m in 15th, disappeared in 16th.

Cannot speak for editions earlier than 14th (1966).

11. 16th Ed.? I don't have my copies to hand.

Addendum: Regarding Q12, in the 14th, table D1 lists maximum ELI's and in brackets has the following:

(Systems operating at 230-250 volts to earth)

12. 1970/71

13. 2004

14. Early 70's I think?

15. This from the on-line Wikipedia:

August 1984: BS 1363:1984 "Specification for 13 A fused plugs switched and unswitched socket-outlets" published. This standard superseded BS 1363:1967. Changes include introduction of sleeved pins on Line and Neutral, metric dimensions replacing inches, specifications added for non-rewirable plugs and portable socket-outlets. The standard was aligned, where possible, with the proposed IEC standard for domestic plugs and socket-outlets.

16. 1981.

17. 1991, I think. Stuff like that went mad in the 15th, then was relaxed in the 16th as the IEE discovered that multiple parallel earth paths could be dangerous.

18. 17th Ed.?

 

[PBC_1966]

Some interesting points in your list. Some thoughts on a few:

Combine the separate lighting and power meters into one.

Did any separate metering continue after nationalization in 1947? If so, then finding dates of last use in each regional electrcity board area might not be too difficult, but if we're going back to the pre-war period, it might become very hard to determine for any specific area given the hundreds of smaller electricity companies which existed at the time. Some may have abandoned it earlier than others, some may have never adopted the practice at all.

Use earths on lights 1966 I think?

The 14th edition 1966 is when it became a requirement to provide an earth at every lighting outlet and switch point. But as I posted elsewhere a few days ago, earths were still required on lighting circuits in many cases under the 13th edition: Where metal switch plates were used, where fluorescent or other discharge lamps were used, where a metallic light fixture was mounted either within reach of somebody on the floor or within reach of other earth metalwork, etc.

Drop the use of ELCB-v

I think that was either with the publishing of the 15th edition in 1981, or possibly an amendment a year or two later. It was certainly regarded as obsolete by the mid-1980's.

Change from L = live to L = line. (If it ever meant live?)

Certainly under the 14th edition the definition of "live" did not include a neutral or other earthed current-carrying conductor. I'm not sure that changed with the 15th edition either - Possibly the 16th edition?

Distance isolator to cooker (if ever)

Yes, there was. Certainly both the 13th & 14th edition required an isolator within 6 ft. of the appliance (changed to 2m with the revised 14th metric edition 1970).

Change from 240 to 230 volt.

Somewhere around 1995 give or take a year, if I recall correctly. Not that anything has actually changed in most places yet!

Change flex colours

Mostly around 1969 - 1971 when brown & blue replaced red & black. The cut-off date in the 14th edition 1970 for use of red/black is 1st April 1971. Use of green/yellow instead of green was recognized a few years earlier though, I think possibly as an amendment to the 13th edition in the early-mid 1960's. The original 14th edition 1966 lists it but still with a note that plain green is preferable. Although I think it was rare, I did once have a couple of appliances from that era with flexes which had red & black combined with green/yellow earth.

Change fixed wiring colours

I think brown/blue became generally available during 2004 (certainly before the introduction of Part P at the beginning of 2005). Cut-off date for "old" was April 2006.

Change from 7/0.012 to 2.5mm²

I assume you meant 7/.029, and Imperial to metric cable sizes in general. That would have been around 1969 - 1970. I believe the 14th edition Wiring Regs. had an amendment for the new metric sizes issued in 1969. The 1970 metric revision ditched all references to Imperial cables completely - A big mistake in my book, given that they were still going to be in use for decades to come!

Change from all copper pins 13A plug to insulated top section.

Somewhere around the early-mid 1990's, again if I recall correctly.

 

[AndyPRK]

"Change flex colours"

1 July 1970 only new flex colours to be used.

 

[PBC_1966]

1 July 1970 only new flex colours to be used.

Where did that date come from? Was that the cut-off date for new appliance flexes perhaps? The 1970 revision of the 14th edition definitely gives 1st April 1971 as the cut-off.

 

[securespark]

Was that the cut-off date for new appliance flexes perhaps?

Da-dum! [Cymbals crash]

 

[AndyPRK]

1 July 1970 only new flex colours to be used.

Where did that date come from? Was that the cut-off date for new appliance flexes perhaps? The 1970 revision of the 14th edition definitely gives 1st April 1971 as the cut-off.

Yes appliance flex. Sorry

 

[PBC_1966]

No need to apologize - I was just trying to equate the two different dates, and had it in the back of my mind somewhere that there was a different date specified for the sale of appliances with the "old" colors.

For what it's worth, here are the relevant tables from the Wiring Regs. 14th edition.

The original 1966 version:

And the revised 1970 edition:

And here's the 13th edition as amended to 1963, this particular scan from the ASEE guide to the Wiring Regs.:

 

[securespark]

Regarding Q12, in the 14th, table D1 lists maximum ELI's and in brackets has the following:

(Systems operating at 230-250 volts to earth)

 

[securespark]

Amended my answers.

 

[PBC_1966]

Amended my answers.

Ah, that's easier to follow!

14th Ed. makes no specific mention of TT supplies, but says that if the earth fault current does not exceed 3x rating of a 3036 or cartridge fuse having a fusing factor exceeding 1.5 or 2.4 x the rating of a cartridge fuse not exceeding 1.5 FF or 1.5 x the tripping current of CB, then earth leakage protection shall be provided.

It wouldn't refer to TT as such, as the whole range of TT/TN designations weren't introduced until the 15th edition. Many of the current-operated ELCB's installed at that time were around 500mA trip.

 

[securespark]

Updated my answers.

 

[JohnW2]

It wouldn't refer to TT as such, as the whole range of TT/TN designations weren't introduced until the 15th edition. Many of the current-operated ELCB's installed at that time were around 500mA trip.

... and that, of course, was perfectly adequate for providing fault protection in a TT installation. It was only subsequently, when RCDs with much lower trip thresholds came along that a whole new 'purpose (require low IΔn) came into being, with consequent eventual changes in regulations.

Kind Regards, John

 

[PBC_1966]

Some of the current ELCB's around at the time were the same assemblies as the voltage-operated types from the same manufacturer with the addition of the appropriate current transformers and a new casing fitting over the whole combined assembly.

I can't remember the model number offhand, but there was a Crabtree current-operated ELCB like that which used the ubiquitous E50 voltage ELCB mechanism inside.

 

[securespark]

Can't find one on YouTube, but this is quite interesting: