≥6-core flex?

[SUNRAY]

This is very interesting/intriguing ...

People have been making all sorts of suggestions (about which I'm pretty nervous!) about getting umpteen cables/cores into the seemingly 'tiny' (maybe 5/8") conduit I'm dealing with, but it seems that whoever did the present wiring even had a problem getting one 1mm² 3C+E cable in!

I've now got that "3C+E" cable out, and drawn in a new length of 5-core flex. I commented before that I could not find he cable sheath at the bottom, so assumed it had been 'cut back', but there was no doubt that what was going into the top of the conduit was3C+E (with sheath). However, having now got it out, look what I found ....

View attachment 418406

.... There was, in fact, only one or two inches of sheath going into the top of the conduit. For the rest of the run down the conduit, the sheath had been stripped off, leaving just the cores (including the bare CPC), which were neatly taped together. I suppose that's not too far off Sunray's suggestion to"use singles", but I have to say that I've never previously seen it done in quite this way

0hhhh yes, not exactly uncommon.

What I will say is if that is an undamaged 5/8" or 16mm conduit of internal diameter around 14mm that 1mm² 3C&E should have almost fallen into it under it's own weight, assuming it hadn't been mangled by some monkey before hand.

 

[JohnW2]

What I will say is if that is an undamaged 5/8" or 16mm conduit of internal diameter around 14mm that 1mm² 3C&E should have almost fallen into it under it's own weight, assuming it hadn't been mangled by some monkey before hand.

Yes, that's what I find a bit difficult to understand. Even I would have expected one 3C+E cable to virtually 'fall down' that conduit, but there has to be some reason why they went to the trouble of stripping it and neatly taping the cores together.

There were, of course, a few moments of 'holding my breath' (and maybe a little 'praying' ) when it 'tightened up' (necessitating a degree of 'brute force') with the old cable half out and the new one half in - but now that I've got beyond that, my 'problem' is obviously now 'sorted' - but with my thanks for all the interest and time of folk in the discussion!

 

[SUNRAY]

Ah just a moment...

Trying to scale from your pic

I'm trying to estimate the ratio between the conductor size and the conduit (silly, I should have done this before)
I estimate ~ 4:1 making the conductor insulation 4mm diameter which I'm pretty sure aint the case,
The offcut of 1.5mm² measures at ~ 2.55mm making that tube ~ 10.2mm.
If 1mm² is ~ 0.2mm thinner it would make the tube ~ 9.4mm or possibly 3/8"????
If that makes the tube ~ 7.4mm internal diameter there aint no way on this earth any cowboy will get a 3C&E down it

 

[JohnW2]

Ah just a moment... Trying to scale from your picI'm trying to estimate the ratio between the conductor size and the conduit (silly, I should have done this before)
I estimate ~ 4:1 making the conductor insulation 4mm diameter which I'm pretty sure aint the case, ... The offcut of 1.5mm² measures at ~ 2.55mm making that tube ~ 10.2mm. ... If 1mm² is ~ 0.2mm thinner it would make the tube ~ 9.4mm or possibly 3/8"???? .... If that makes the tube ~ 7.4mm there aint no way on this earth any cowboy will get a 3C&E down it

Interesting thinking, but .....

(a) ... it was you, not me, who suggested that the conduit was 5/8" ​

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(b) ... my calipers say that the OD of the conduit is about 12.5 mm. It's pretty thin-walled, I'd say definitely no more than 1 mm at most, so the ID is probably at least 10.5 mm. I can't actually measure the ID directly now that the new cable is in it.​

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(c) ... the couple of inches of sheathed 3C+E in the conduit at the top (I think it's definitely 1.0 mm²) was not remotely tight in the conduit​

 

[SUNRAY]

Interesting thinking, but .....

(a) ... it was you, not me, who suggested that the conduit was 5/8" ​

My apologies but at a glance from this distance t'aint easy

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(b) ... my calipers say that the OD of the conduit is about 12.5 mm. It's pretty thin-walled, I'd say definitely no more than 1 mm at most, so the ID is probably at least 10.5 mm. I can't actually measure the ID directly now that the new cable is in it.​

1/2"is bigger than I have guestimated but again from a photo at this distance and the left of the pic is somewhat indistinct.

(c) ... the couple of inches of sheathed 3C+E (I think it's definitely 1.0 mm²) was not remotely tight in the conduit​

IIRC 1mm² is ~8*5mm so that makes loads of sense but wouldn't require much deviation to touch the corners. I imagine it would have pulled in quite easily but probably not pushed the 5ft of so you'd require.

 

[JohnW2]

My apologies but at a glance from this distance t'aint easy ... 1/2"is bigger than I have guestimated but again from a photo at this distance and the left of the pic is somewhat indistinct.

I'm not knocking you - as you say, it certainly ain't easy from a (poor) photo. Your suggested interpretation did (and still does) seem 'reasonable' to me.

IIRC 1mm² is ~8*5mm so that makes loads of sense but wouldn't require much deviation to touch the corners. I imagine it would have pulled in quite easily but probably not pushed the 5ft of so you'd require.

Yes, I can but assume that such must have been the case. I can't imagine they would have gone to the trouble of stripping the sheath etc. unless they had first tried, unsuccessfully, to get the cable through without doing that.

Mind you, I remain very doubtful about the suggestion that one could get ('easily'or otherwise) two 3C+E cables (with sheaths!) though a 5/8" conduit!