Terminal blocks in sockets

[JohnW2]

BS 7609 references BS 4579-1:1970, which is about test specifications for compression joints: resistance, tensile strength etc. The scope of that Standard has no minimum CSA but it does say:

The conductors for which the connectors may be suitable may be tinned or untinned, stranded or solid...

Thanks. That statement seems very clear.

There's also BS 5G 178-1:1993: Crimped joints for aircraft electrical cables and wires. That makes no reference at all to solid core conductors, but it does mention strands of a core. It could be that solid core conductors are prohibited entirely in aircraft, which would seem sensible to me.

As I've been saying, I can certainly see good reason for specific concerns about crimped joints (in general) in aircraft (and spacecraft), and the NASA document seems to imply that they feel that the risks are greater with solid conductors. As you say, one could also produce an argument for solid conductors, per se, being prohibited in aircraft/spacecraft - although the existence of those statements in the NASA document would seem to imply that they do use solid conductors in some situations.

Are solid-conductor cables widely used outside of domestic wiring?

I would have thought not (other than in 'domestic-like' wiring in commercial/industrial installations), but aptsys's comment above may mean that DNOs do use (large) solid conductors in their distribution networks, even though that would somewhat surprise me. Apart from anything else, I would have thought that solid conductors would become unmanageably stiff above 10 mm².

As you go on to imply, very small solid conductors are common - particularly in relation to telecoms/data - but I've never heard of crimped joints being used for such cables, and find it hard to imagine that they ever would be.

Kind Regards, John

 

[aptsys]

Do you mean solid conductors?

Kind Regards, John

Yes, waveform cable for example.

 

[JohnW2]

Yes, waveform cable for example.

Fair enough. Needless to say, something I only 'know about', never having met any!

Having had a quick look around, it is apparent that, as you said, the (solid) conductors of such cables are crimped. However, I imagine that, because of the different physical properties, the subject of crimping aluminium conductors is probably rather different from that of crimping copper ones.

Are you aware of any types of solid copper conductors which DNOs crimp?

Kind Regards, John

 

[EFLImpudence]

Are you aware of any types of solid copper conductors which DNOs crimp?

Ones they have to bolt to terminals -

You will note the difference from the earlier picture.

https://www.powerandcables.com/copper-cable-lugs-for-special-applications/

Scroll down.

 

[JohnW2]

Ones they have to bolt to terminals -

Interesting. I also note ...

A hexagonal indent crimping is being recommended – again it has to be observed that both cable lugs and crimping tools come from the same manufacturer. ... Cable lugs for solid conductors can be recognized by their smaller tube diameter and the marking “E”. For example: KL 10 50 E.

... so, if I read that correctly, a 'special' type of crimp, and a 'special' crimping process, for solid conductors?

Kind Regards, John

 

[EFLImpudence]

Yes, E type - electrolytic tin plated copper - whatever benefit that produces, and, more importantly importantly I would think, crimps that 'fit' the conductor.

I don't see why crimps for 'our normal' solid conductors are not made. They could be two correctly sized adjacent tubes with a suitable tool. There would be no need for butt crimps as both conductors could be inserted the full length of the crimp (obviously more difficult for stranded).

Perhaps deemed unnecessary because they can be twisted and screwits used.

 

[JohnW2]

I don't see why crimps for 'our normal' solid conductors are not made. They could be two correctly sized adjacent tubes with a suitable tool. There would be no need for butt crimps as both conductors could be inserted the full length of the crimp (obviously more difficult for stranded).

That link seems to be indicating the desirability of 'indent' crimping (rather than simple 'squashing'), and I wonder if that is practical with the small solid conductors 'we' normally deal with? (they say that the smallest crimp for solid conductors is 'usually' 6mm²).

Kind Regards, John

 

[EFLImpudence]

Aren't the indent ones just for stranded?

 

[JohnW2]

Aren't the indent ones just for stranded?

As I quoted before, in relation to the crimping of solid conductors, it says ..

A hexagonal indent crimping is being recommended – again it has to be observed that both cable lugs and crimping tools come from the same manufacturer.

Kind Regards, John

 

[EFLImpudence]

Right. Don't know, then.

 

[JohnW2]

Right. Don't know, then.

Nor me. However, a quick look around finds that most indent crimper tools are for 10mm² and above.

Kind Regards, John

 

[mattylad]

FGS!
To stop such lengthy discussions just extend the damn cables using a terminal block and wrap the block in the compulsory insulation tape

 

[winston1]

No need for the insulation tape. It is inside an enclosed box! You don't put tape on the socket terminals do you?

 

[JohnW2]

FGS! To stop such lengthy discussions just extend the damn cables using a terminal block and wrap the block in the compulsory insulation tape

I think the OP was sorted out a long time ago.

The subsequent discussion is of far wider relevance. Many, perhaps most, electricians appear to believe that crimping small (≤2.5 mm²) solid copper conductors is perfectly OK, although some of us have been brought up (maybe incorrectly) to believe that it should not be done. Attempting to determine the facts would therefore seem to be a useful exercise. It doesn't matter to me, but it could to others.

Kind Regards, John

MOD: I feel in its current form this thread has gone far enough from the OP's original question. Please feel free to start a new thread.