Advice on Pulling 6 mm2 single core cable through 20 mm Conduit

[Maximus Rumpas]

Hi,

I would like to ask your advice about how difficult it might be to pull cables through 20 mm plastic conduit. (easy, moderate, hard, impossible)

I am running two separate lines for a cooker and hob in 6 mm2 single core stranded cable. Both runs will follow the same route.

4 meter run from distribution board via 90 degree inspection bent to an inspection box next to soil stack.

Next 2.5 meter run through Bathroom/Kitchen wall to an inspection box under sink (minor set to allow for wall levels)
Then either
4 meter run, chased into wall via 90 degree inspection bend to a third inspection box.
or
4 meter run via 300 mm drop to Floor level - two 90 degree inspection bend to the third inspection box.

Lastly 1.5 meter run to cooker or hob isolation switch.

On completion permanent access to inspection boxes - limited access to 90 degree inspection bends.

Your thoughts please.

Kind regards
Max

 

[vjsmarwick]

Ok as I am in temp accommodation at the moment and don't have access to my bible I have been at my mates and trying to figure this out but the more we look at it the more confused we are becoming, for a 3 meter length the correction factor for 6mm is 88 but over 3 meter it drops to 58 i would have thought this would have been the other way around but there you go never mind that but if the op could have kept the run between his boxes to 3m instead of 4 then he could in fact run all 5 conductors needed in a 20mm conduit and not break a single rule but the extra meter makes it not work but its been a nice little refresher for me thanks guys but only conduit I use these days is to sleeve an outside light cable and I am sure in the multitude of regs changes since I needed to know they have changed this the same as everything else so I stand corrected sorry for doubting anyone but it was all over a meter

 

[PEG]

"that amount of fill through a male bush is just not acceptable..." I'm guessing your not an Elton John fan , eng...

 

[Engineer54]

Ok as I am in temp accommodation at the moment and don't have access to my bible I have been at my mates and trying to figure this out but the more we look at it the more confused we are becoming, for a 3 meter length the correction factor for 6mm is 88 but over 3 meter it drops to 58 i would have thought this would have been the other way around but there you go never mind that but if the op could have kept the run between his boxes to 3m instead of 4 then he could in fact run all 5 conductors needed in a 20mm conduit and not break a single rule but the extra meter makes it not work but its been a nice little refresher for me thanks guys but only conduit I use these days is to sleeve an outside light cable and I am sure in the multitude of regs changes since I needed to know they have changed this the same as everything else so I stand corrected sorry for doubting anyone but it was all over a meter

I can't check with anything to hand, but i'm pretty sure your wrong, maybe your relying on straight runs i would imagine here. Now try working it out with a single bend, as the OP has stipulated. I think you'll find a big difference in the outcome!! And that's apart from actually getting the cables pulled in to a 20mm conduit!!

 

[ipf]

And, with these short straight lengths of 20mm conduit, imagine removing and reinserting at every bend, elbow or even conduit box......could be quite difficult.

 

[GLENNSPARK]

they say the older the dryer, try a woman not a granny richy3333

lol!!...

 

[grantr37]

you can get bends and inspection elbows at screwfix, would use metal conduit myself with singles and use plastic just for telecom/data etc but that's just me maybe....

 

[Engineer54]

you can get bends and inspection elbows at screwfix, would use metal conduit myself with singles and use plastic just for telecom/data etc but that's just me maybe....

Using inspection elbows pulling in 5 6mm singles and you can guarantee scuffing insulation off the cables!! Inspection elbows and Tee's haven't been allowed on any major specified project installation since the 80's, these things can rip insulation to shreds. They should have been pulled/discontinued completely in my opinion... Inexperienced electricians that can't fabricate a decent conduit system tend to like them, ...though why they don't use Tee conduit boxes or angle boxes i don't know!! lol!!

 

[rmdes]

I've done it so it is possible gonna need two of you to feed and pull lots of cable lube and lots of swearing. (don't use washing up liquid it damages the cable). It's unfortunately a long process of pulling through a short length then lube and pull and lube, but doable.

Good luck

 

[i=p/u]

I had to tap off trunking one day in steel conduit and instead of bending like a master i used boxes to get to desired place, i can do 90 bends and thread it only lol the rest always ends up wrong.... But sure someday il jump on a job where there is loads of piping and get chance to practice .

Was considering buying pipe myself but havent yet.

 

[i=p/u]

Il say it again 5x6mm cables aint right in a conduit never mind with bends.

 

[rmdes]

Sorry must of read it wrong i just thought you were pulling 3x 6mm

5x 6mm not gonna happen in a 20mm conduit,
The capacity for heat etc and bends no chance

 

[Engineer54]

I've done it so it is possible gonna need two of you to feed and pull lots of cable lube and lots of swearing. (don't use washing up liquid it damages the cable). It's unfortunately a long process of pulling through a short length then lube and pull and lube, but doable.

Good luck

You've done it have you, ...5 X 6mm in 20mm around bends?? Stretch any of the cables pulling them in did you??

Sorry must of read it wrong i just thought you were pulling 3x 6mm

5x 6mm not gonna happen in a 20mm conduit,
The capacity for heat etc and bends no chance

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EDIT.... That's more like it!! Must have crossed on posting times lol!!