Inline Crimps

[Andy Wade]

Part P makes the fixed electrical installation of a dwelling a controlled service under the building regulations. Therefore any work done to such an installation is within its scope, whether notifiable or not. IOW Part P always applies.

All the Part P legislation now says is:

"P1 Reasonable provision shall be made in the design, installation, inspection and testing of electrical installations in order to protect persons from fire or injury."

However (1) note that there's no explicit reference to BS 7671 in the legislation. Note also that the previous Part P2 requirement, which required "information" (i.e. documentation) to be provided was removed in the amendment of April this year. Thus there would seem to be no explicit legal requirement to provide certification.

However (2) Para 1.8 of Approved Document 2 states that compliance with Part P can be demonstrated by the issue of an appropriate electrical installation certificate under BS 7671. Thus it would be difficult to challenge the assumption that certification is required for new installations, rewires and what BS 7671 calls "additions and alterations."

However (3) what we're talking about here possibly isn't an "alteration," it's a "repair." Or does inserting a crimped joint in a cable (not accessible for inspection) where previously there was none constitute an alteration? - I don't know the answer to that. If it is an alteration a minor works certificate (MWC) would be required, but if only a repair BS 7671 doesn't require a certificate (although para 1.13 of the approved document describes it as advisable).

So, to come to Steve Dawson's defence (and he has been posting here for a long time, BTW) I think he has a valid point. Not that Dave shouldn't be doing the work, but that he should (if competent) be testing and certifying it. OK, this is a borderline example, but there's no doubt that many of the jobs listed on

are definitely additions or alterations which do require testing and MWCs.

[The Medway Handyman]

Thanks for the comments & info.

Which ones would you suggest require testing? I asked my local Trading Standards to perfom a volutary investigation of the website to ensure no unfair or incorrect claims were made, but of course they aren't electricians.

My intention is to stay inside the regs, so any advice would be welcome.

[Andy Wade]

He should also do the full set of tests required for an MWC, i.e.:

(i) continuity of the CPC (ii) insulation resistances (iii) earth fault loop impedance (Zs) (iv) polarity (v) RCD operation, if applicable.

[Dave Plowman (News)]

You use heatshrink over the entire lot - to replace the outer sheath, where you've made the joints. The stuff with internal glue is the best as it's thicker - otherwise use two layers of ordinary stuff if you can.

Easy enough first time you do anything.

[Andy Wade]

- Replace light switches . . . . . . . = repair/maintenance

- Fit dimmer switches . . . . . . . . = alteration

- Replace ceiling roses . . . . . . . = repair/maintenance

- Fit Ceiling Fans . . . . . . . . . . = addition

- Replace damaged sockets . . . . . . = repair/maintenance

- Convert single sockets to two way . = alteration

- Convert double sockets to three way = alteration

- Convert single sockets to four way . = alteration

- Any 'like for like' replacement . . = repair/maintenance

The additions and alts certainly do; for the repairs and maintenance items it's a moot point, but do read 1.13 in the Approved Doc.

- Fit outside lights = addition, and notifiable in some circumstances.

It's another moot point whether that gets you off the hook. You are still adding fixed electrical equipment and presumably fixed wiring thereto, forming part of a fixed electrical installation and therefore within the scope...

Quite. Sadly, it's probably your PL insurance company that will have the final word. If you are going to certify they will probably insist that you get the C&G 2381 & 2391 tickets (not that those are particularly difficult if you know your stuff). That would then give you the advantage of being able to do notifiable work for just the cost of a building notice and minimal fuss (see 1.22 in the Approved Doc.)

[The Medway Handyman]

Hmmm. In one respect it's changing one switch for another switch with no alteration to the wiring, albeit a different type of switch. How far does this go? For example replacing a defunct B&Q own brand switch with an MK brand?

Again, one type of light fitting for another (since most fans have lights as well)? Or not?

I do this using the kit type socket converters like this

since these are widely available to joe public is that OK?

I'll make a point of that - thanks.

I'll look into that - thanks again.

[Stephen Dawson]

Only about 6 or 7 years from memory, so no I have not been here long in relation to the age of the planet.

Steve Dawson

[Stephen Dawson]

For everbodys info,

My credentials

Apprentice electrical fitter for Southern Electric Plc 1988 - 1992 High Voltage Distribution Fitter for Southern Electric, carrying out maintenance and construction on all voltages ad systems between 12V dc and

132KV 1992 - 2001 Started own business in 1998 working part time on days off. Changed name in 1998 to Fox Electrical, Left Southern Electric in 2001, to work full time on my business. Became ECA registered contractor in 2002, NICEIC registered in 2006.

I have a CG232pt 2, CG2377, CG2380, CG2391, have finished the CG2400, but not had time to do the design assignemnt yet.

Run a small electrical business, doing a wide variety of jobs, and diagree with the application of Part P. but agree agree with the theory, but it is not working.

My original point regarding Dave's post was that I have and do such repairs, using crimps and heatshrink, but some time the crimp does not hold or I missed for some reason. Any way with out testing it correctly how are you to know whether or not the repair is safe??

The point was to get Dave to think about the consequences of a failed repair, and what he would do to defend himself, if someone was injured. No scarey bits intend, just to open your eyes to what may occur.

You nay create a high resistance joint which could potentially start a fire, or maybe the earth ( or 'circuit protective conductor' to give it it's proper name maybe open circuit. Where would the potential fault go in a class 1 appliance?? Possible thru the case and the person touching.

A way of demonstrating that you have carried this out correctly is to issue test certs, in this case we would look to issue a Minor Works Certificate, because the work that has been carried out has interfered with the characteristics of the circuit.

I have no gripe with Dave, he is good and proactive group member, but needs as a fledging business to be aware of potential pitfalls. It would be the same as be putting in a gas heating system, but I have no idea how to commision it or what is the correct burning characteristics.

Oh, one more thing, everybody on this group knows I am awful at speeling and grammar, which is why I build things, not wite things.

Now, lets all play nicely again :-) and not jump down people's throats when they offer advice, unless it is bad or dangerous.

Regards to Everyone, even Dr Drivel

Steve Dawson

[Guy King]

The message from "Stephen Dawson" contains these words:

Then you should know better than to make daft comments about contributors having particular professions and whether they should ask for help.

[John Rumm]

Perhaps "sod all" was a little strong... of "limited use" may be fairer. Sometimes you can pull a new wire through, but often you find bits at the end that get blocked off with plaster, or it is on a brick or block wall where you end up snagging the new cable on mortar joints.

[John Rumm]

Well it does depend on whether your crimps are insulated ones or not ;-)

With uninsulated ones, then you must use heatshring on each wire - it covers the whole crimp and a bit of wire either side.

With insulated crimps then you can do without the extra heatshrink inside so long as the insulated crimp has a skirt section to ensure there is no possibility of copper being visible at the base of the crimp. Having said that there is nothing to stop you using heatshrink on the individual wires even if you do have insulated crimps.

[John Rumm]

There is an argument that some of these should be done before[1] making the repair as well, otherwise there is the danger that you uncover pre-existing faults after you have made alterations and the client is going to think it is your fault!

[1] obviosuly which tests you can carry out (other than iv and v) will depend ont he nature of the cable damage.

[Dave Plowman (News)]

Just as a follow up, the insulated type may be approved, but have you ever removed the insulation and examined one after crimping? They look terrible. I far prefer non insulated types where the crimper has shaped jaws which turn one side of the crimp sort of in on itself. They may both be functional, but one 'looks' so much better.

[Andy Wade]

The installation consists of electrical equipment and wiring. You're changing the type of equipment fitted so that's an alteration. A trivial one, certainly, but still an alteration.

If the same no. of gangs and ways then that's a like-for-like replacement.

Not (IMHO).

Well it's OK, provided the 13 A overall rating is sufficient for the reasonably anticipated loading, but it's still an alteration to the circuit. The "widely available to joe public" bit is quite irrelevant, consumer units and any other items of electrical equipment you'd need in a house are equally widely available.

[The Medway Handyman]

It was a blond moment John, or possibly a grey one. I didn't know they made uninsulated crimps! I've only ever seen insulated ones.

Doh!

[Peter Parry]

Invariably the cause of this is the use of incorrect crimps and/or tooling. The standard Partpee electrician carries a cheap (rusty) non pressure regulated pressed metal squeeze crimp pliers tool and a box red blue and yellow (RBY) crimps of unknown (other than they were the cheapest) provenance.

A crimp joint done with the correct ratchet tool and using RBY crimps meant for solid core cable (most are not) will always hold.

The correct test for a crimp joint is to exert the correct pull out force on it and check it holds. No electrical test can test a crimp joint for any fault other than ones so gross they should be visible to the naked eye.

If all you could show was you had used the wrong tool, the wrong component and the wrong test I'm not sure this would be much of a defence, certificates or not.

No it isn't, that simply proves you have issued a certificate. If it is based upon an inappropriate test for the work done it is meaningless. I can consistently crimp you many joints with the toy pliers so beloved of electricians which would pass all your tests and fail within weeks. The way to do the work correctly is to use the right tools and components in the first place. To do this you need to know what the right tool and components are - something most electricians (in this case) don't.

[Tony Williams]

I have always been doubtful about insulated crimps for solid wire. ISTM that a crimp for solid wire should be thick-walled, uninsulated, with visible corrugated lines inside. With the correct tool those corrugated lines should pierce the solid wire and form a gas-tight joint.

[Dave Plowman (News)]

This is the tool I use:-

these crimps:- you saying neither is really up to the job? If so, could you give some recommendations?

[John Rumm]

My fault for not explaining all the assumptions in the first place...

(I only buy the insulated ones myself as well)

[Peter Parry]

The tool is fine - it's the sort at

which are useless.

The crimps, I have no idea. A simple but accurate test of tool and cable is to join the wire you want in the way you want and try to pull it apart. There is a full test spec on a Swedish web site somewhere but as a guide, for red terminals hang a gallon container of water from the joint - it should hold for at least a minute. (blue

- 2 galls, yellow, 3 galls).

A pullout force calculator for BS6516 Pt2 is available at

test blade connectors clamp the blade part only in a vice and hang the container from the crimped wire).

Usually only the more expensive crimps will claim suitability for both stranded and solid wire and the wire diameters differ from those for stranded wire - the single strand range being a somewhat narrower band as the single wire doesn't deform as well as stranded.