Questionable Conductor Size

[Spenny]

I am in the process of installing a 5 core 70mm feeder cable for a DB. 70mm cable lugs are too large for the cores but 50mm fit perfectly. I have taken this up with the cable supplier. Their response was that 50mm lugs are often used om 70mm cores?


Having been in the trade for 41 years I have never heard of this. I normally have to file a taper on to the copper conductors to get lugs to slide on as the fitting is that tight. Now I am told you can easily use a much smaller lug? It makes no sense.

I am of the opinion the cable is under sized yet the OD is 43.3mm which is correct for a 5 core 70mm. Anyone else come across this?

 

[westward10]

Sounds odd the difference in csa is quite considerable. A 50mm lug should not fit 70mm. What brand is the cable.

 

[Spenny]

Sounds odd the difference in csa is quite considerable. A 50mm lug should not fit 70mm. What brand is the cable.

EL SEWEDY an Egyptian manufacturer supplied through Cleveland Cables. It is marked as conforming to BS6467 CE

 

[James]

The only time I’ve come across something similar is if the conductor is round and the lugs are designed for shaped core.
But it is sounding suspicious

 

[Spenny]

The only time I’ve come across something similar is if the conductor is round and the lugs are designed for shaped core.
But it is sounding suspicious

The conductors are round and I have tried 3 types of round lugs, all with the same result. I crimped a 70 and 50 on to two cuttings, the 50 is perfect the 70 is a shambles.
A 50mm 5 core is not rated for this job as I am installing a 250A breaker so it is critical. The fact that the cable is marked 70mm 5C has me scratching my head.

 

[Bobster]

What measurements have you taken from the actual copper of a core?

They can't hide from a mistake with measuring it.

^Agree with the above, only time I've seen them loose is people mistakenly using the improper lugs for shaped/non shaped cable.

 

[Spenny]

What measurements have you taken from the actual copper of a core?

They can't hide from a mistake with measuring it.

^Agree with the above, only time I've seen them loose is people mistakenly using the improper lugs for shaped/non shaped cable.

The strands are not round so I can't measure the OD accurately. There are 19 of them though so if it's 70mm each should be 3.68 mm. If it's 50 they would be 2.63mm. A strand fits a 2.5mm crimp perfectly.

 

[Spenny]

This is one of the "70mm" conductors used as an earth bond.

 

[westward10]

If your pic is showing a 70mm then it should not go into a 50mm lug.

 

[Bobster]

I'd put money on that being 50mm or slightly less actually, notice the wings forming on the side of the lug where it's crimped. This shows an improper match between cable/lug/crimp die.

 

[Sparky Pat]

Be interesting to know what BASEC say about it.

 

[westward10]

What happens when you use a 70mm lug with a 70mm die.

 

[snowhead]

This gives the impression El Sewedy are compliant with BASEC, but with no reference to the quoted BS 6467CE

Egytech Cables (El Sewedy) | BASEC

Find all the BASEC product and system approvals that are currently active for Egytech Cables (El Sewedy). Download Egytech Cables (El Sewedy) relevant certificates approved by BASEC.

www.basec.org.uk

 

[Bobster]

It's an odd standard to reference for a cable

BS 6467
Electrical apparatus with protection by enclosure for use in the presence of combustible dusts. Specification for apparatus

 

[Spenny]

This is the official line from the wholesaler. Data sheet supplied.


The conductor is an compacted conductor.





FYI - A compact stranded conductor is a round or sector conductor having all layers stranded in the same direction and rolled to a predetermined ideal shape. The finished conductor is smooth on the surface and contains practically no interstices or air spaces. This results in a smaller diameter.





I can confirm from the Conductor Resistance on the Test Certification that the cable is 70mm..

 

[westward10]

They have worked miracles to slim down a 70mm so it fits a 50mm lug.

 

[Spenny]

I will ductor the length tomorrow and calculate the resistance value expected. This just does not add up to me.

 

[static zap]

I will ductor the length tomorrow and calculate the resistance value expected. This just does not add up to me.

I like it ,if they have squashed the air out,without making it brittle locally.

 

[James]

I like it ,if they have squashed the air out,without making it brittle locally.

So similar to using shaped conductors rather than round to get a smaller overall diameter on the multi core cable, they have taken a stranded single core and run it through a series of rolls so the strands become shaped.

 

[Bobster]

So similar to using shaped conductors rather than round to get a smaller overall diameter on the multi core cable, they have taken a stranded single core and run it through a series of rolls so the strands become shaped.

Yes but shaped conductors still have a CSA of 70mm, shaping them only improves the overall diameter of the cable.

This clearly is not a 70mm cable.