pulling SWA through conduit.

[1Justin]

32mm plastic conduit. Intention is to run it 6M under concrete floor and use bend spring on ends to bring it vertical. Conduit will be cut off flush with FFL.

Concerned about the bends, do you think I'll pull through a 6mm SWA after the event or would you install it before laying the floor?

 

[ruston]

Use the proper ducting and you can buy the preformed bends , that should make the job a lot easier. Slightest kink and you know whats next lol.

 

[1Justin]

Use the proper ducting and you can buy the preformed bends , that should make the job a lot easier. Slightest kink and you know whats next lol.

I was guessing I'd get more gentle (ie easier) bends with the spring. I'd sooner go preformed. Would 6mm SWA go round 2 of those do you think?

 

[Plonker 3]

I would use 2 manufactured bends and pull the cable through before laying it in position.

 

[ruston]

I was guessing I'd get more gentle (ie easier) bends with the spring. I'd sooner go preformed. Would 6mm SWA go round 2 of those do you think?

Just one at each end of the run?

 

[ruston]

I would use 2 manufactured bends and pull the cable through before laying it in position.

So would I.

 

[Engineer54]

Can't see you having much of a problem pulling either a 2 or 3 core SWA cable through a 32m duct. Personally, if there is any chance of damage to this SWA cable if pulled in prior to use, i'd rather pull in a suitable draw line and install the cable later.

Manufactured slow 90 deg bends are fine, you may have a problem with manufacturing them yourself, i'd heat the area of PVC duct first before trying to form them with the spring if you do go down that route.

 

[1Justin]

Thanks All. Manufactured bends it will be then. If I trust the builders I'll install it beforehand just in case.
Rgds

 

[PEG]

Another detail to watch,is which side of the DPC you will be,and how you breach it,if you have to.

Worth a thought,if cast over insulation or is set for wet UFH.....or just a eagle-eyed BC inspector :icon12:

 

[Darkwood]

I assume you have checked your bending radii will comply on the swa when using pre-set manufactured bend...?

 

[1Justin]

I assume you have checked your bending radii will comply on the swa when using pre-set manufactured bend...?

I was only assuming "sweep.radius" bends anyhow (or DIY). The clipsal/Schneider one is > 300mm on the 32mm (wow) and 150 on the 25mm. Good point though.

 

[7029 dave]

IMO, I would not use factory bends, pull slow bends with your spring.

 

[R G]

I would use 2 manufactured bends and pull the cable through before laying it in position.

Defo the way to do it .....

 

[Engineer54]

Defo the way to do it .....

Not if the cable cable is just going to lay on the floor waiting to get damaged by the builder or whoever. Id say that it's defo not the way to do it!!

 

[R G]

Not if the cable cable is just going to lay on the floor waiting to get damaged by the builder or whoever. Id say that it's defo not the way to do it!!

I would agree with you with builders in the area , but I would ensure some protection is in place for the cable and advise them about care to be taken , if the guys are that bad then maybe they would dislodge any joints on the conduit , so Pulling the cable in and protecting it is what i would do ..

 

[edexlab]

You can't always win with builders,
One job we were told "Install the cable so we know its in"

Came back cable was mangled 4"above floor level!

Lesson learned next job the instructions were;

"Those idiots can't be trusted we'll use a larger duct and pull it through later".

Returned 3 weeks later duct is rammed full of concrete at both ends, luckily the carpark hadn't been done yet and it had to be dug up , the whole duct 20m long was full of the stuff

It turned out when they poured it in the guy kept using the duct as a parking point for the nozzle as it wouldn't shut off properly and he didnt want to make a mess!

 

[Engineer54]

I would agree with you with builders in the area , but I would ensure some protection is in place for the cable and advise them about care to be taken , if the guys are that bad then maybe they would dislodge any joints on the conduit , so Pulling the cable in and protecting it is what i would do ..

I don't know about you, but i like most electricians would cement/glue any manufactured bends and joints together, not just rely on a push joint... Builders just can't be trusted to look after an installed cable over a period of weeks, no matter what temporary protection you provide at both ends....

 

[Deleted member 26818]

I wouldn't use any conduit at all.
Ducting, or lay the SWA cable direct in the concrete.

 

[PEG]

You can't always win with builders,
One job we were told "Install the cable so we know its in"

Came back cable was mangled 4"above floor level!

Lesson learned next job the instructions were;

"Those idiots can't be trusted we'll use a larger duct and pull it through later".

Returned 3 weeks later duct is rammed full of concrete at both ends, luckily the carpark hadn't been done yet and it had to be dug up , the whole duct 20m long was full of the stuff

It turned out when they poured it in the guy kept using the duct as a parking point for the nozzle as it wouldn't shut off properly and he didnt want to make a mess!

I know THAT feeling well.....i was on a piling job in Tel Aviv,Israel,years ago,and the pour was on,2 hours in,and they couldn't work out why the last 40 cubic meters of concrete had not expelled much Bentonite,from the pile...when the top 5 meters was pumped out,the damaged 40" sewer could be seen.....the 40 cubes of compo however,was site-seeing round the town...

Ironically,the same thing occurred in my local town,on a smaller scale,which required a specialist team of Irish lads,3 months to sort :icon12: