Wire 1

[Jack Nicholson]

Hi everyone.
I've attached a wire installed in our plant. This is a cross sectional area of LV wire. Would you please explain what are those six sub layer??

 

[itsmoked]

I'll guess:
The five surrounding wires are L1, L2, L3, a Neutral, and the yellow/green one is the Ground.

The central unjacketed one is the same as the outer surrounding shield, basically strength members, but wait for someone who knows for sure to confirm or correct my offering.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[GroovyGuy]

Hi Hosein,
That is one strange cable. ie Served-wire armour and a center support core. Certianly not common in N.A.
I saw one like that many years ago while working in an underground mine. It was suspended (vertically) in a ventilation shaft for several hundred meters.
I am curious, what industry are you in, and where are you located?
Regards,
GG

ps itsmoked is correct. The cable has 3 phase conductors plus neutral plus ground.


The pessimist sees difficulty in every opportunity. The optimist sees the opportunity in every difficulty.
Winston Churchill

 

[Jack Nicholson]

Working in petrochemical, C2+ recovery and fractionation. Why this is weird cable?

 

[Mbrooke]

That looks like SWA cable. Note looks, not necessarily is.

 

[ScottyUK]

Looks like a fairly standard cable to BS 5467 or a derived standard.

Core colours are the old British colours, pre-European harmonisation in the mid-2000's: red/yellow/blue phases, black neutral, green & yellow earth.

The central 'core' is simply a plastic spacer to make the other cores lay in a more circular pattern to aid manufacture.

The outer sheath is probably PVC but could be a low smoke & fume type. The armour is single-layer steel wire, and the inner serving is likely PVC but again could be an LSF type. The conductor insulation could be PVC, LSF or XLPE. No way to tell from that photo.

 

[ppedUK]

I agree with Scotty mostly, except that its not quite a "standard" cable (not BS Standards anyway), although its construction does look similar to a BS type cable. The G/Y earth core is unusual in an SWA cable and also the Earth and Neutral cores look to be half of the CSA of the phase conductors. We in the U.K. stopped using half size neutral cables some 30-40 years ago. Be careful using this cable if you have high neutral or 3rd harmonic currents in your circuit.

The insulation of the phase and neutral conductors looks like XLPE, as the core colours are laid over clear insulation, however the G/Y earth core could be PVC as that is a solid colour, but that would be one strange cable make-up. Check the cable sheath for markings and construction standards it was manufactured to.

 

[JG2828]

If you post the part number printed on the side of the cable we might be able to find more information.

 

[JG2828]

Is this the answer you are looking for?

http://www.openelectrical.org/wiki/index.php?title=Cable_Construction

 

[ScottyUK]

Well spotted ppedUK, I missed the difference in conductor sizes. If it is a hybrid XLPE / PVC insulated type then it is indeed an oddity.

 

[7anoter4]

In my opinion, this is a cable fabricated between 1977 and 2004 -according the core colour, see:
Electrical wiring in the United Kingdom

https://en.wikipedia.org/wiki/Electrical_wiring_in_the_United_Kingdom#Conductor_colours

I think it is PVC insulated copper conductor of 50 square mm-since the armour steel wire as per IEC 60502-1 Table 9 – Nominal diameter of round armour wires- has to be 2 mm, then the copper wire diameter is a bit less than 2 mm. [19 wire ungrounded conductor and 7 wire reduced neutral could be 70/35 or 50/25 only]

 

[7anoter4]

At the second opinion the conductor cross section has to be 70 sqr.mm.
The bedding is exaggerated. In my opinion, the bedding was executed using a pressure die for 3*185 mm^2+neutral and the bedding thickness is 10 mm more than IEC 60502-1 recommends [average thickness unsymmetrical]. Usually vacuum die has to be employed. The overall cable diameter is 10 mm more than the fictitious [calculated according IEC 60502-1 ].

 

[GroovyGuy]

Hi Hosien,

I was referring to my limited experience with cables here in NA. A SWA type cable is a rarity here in NA, although I am aware that SWA is used elsewhere in the world.
Regards,
GG


The pessimist sees difficulty in every opportunity. The optimist sees the opportunity in every difficulty.
Winston Churchill