PVC fitting joints - why no plain ones?

[falcon786]

The Tee and Elbow are for electrical work, need to re-run some house to boundary wall underground conduits that had the inspection caps (leaked and conduit filled with water - previous owner installed apparently...) - the reason for the specific 90 degrees is that there are established trees with root systems that don't allow me to use the gentler curve 90's. The Tees will be used for running off the main conduit where needed - again, the current Tees have inspection caps and they also leaked. I'm happy to not have inspection caps or mess around with sealing them for underground laying, would rather re-pull the cables if and when the time comes for this in future.

Easiest and surest way to seal up those units with inspection covers is to go to any good electrical supplier and buy a joint splicing kit for a 16mm Armour cable or bigger,use the liquid resin in there to fill in the gaps,this is normally what's used for permanent underground cabling also and it's pretty robust and hard wearing,like an epoxy.

 

[Billy]

Why not just use a cable instead of conduit? No moisture problem, easy bends round obstructions. Meets regulations.

There is a limit to the number of bends without an inspection point, two if I remember correctly.

 

[howardb]

My first though is places that do koi ponds. They'd likely have something like this..

Thanks, will do some more looking around.

Easiest and surest way to seal up those units with inspection covers is to go to any good electrical supplier and buy a joint splicing kit for a 16mm Armour cable or bigger,use the liquid resin in there to fill in the gaps,this is normally what's used for permanent underground cabling also and it's pretty robust and hard wearing,like an epoxy.

Will keep this in mind - I bought a few of those kits a few months ago for another project; think I have one left over.

Why not just use a cable instead of conduit? No moisture problem, easy bends round obstructions. Meets regulations.

There is a limit to the number of bends without an inspection point, two if I remember correctly.

Billy, what cable do you mean - I thought all underground routed wire had to be in conduit? There are max 2 bends in each run, so am interested in the cable suggestion.

 

[savage]

The Tee and Elbow are for electrical work, need to re-run some house to boundary wall underground conduits that had the inspection caps (leaked and conduit filled with water - previous owner installed apparently...) - the reason for the specific 90 degrees is that there are established trees with root systems that don't allow me to use the gentler curve 90's. The Tees will be used for running off the main conduit where needed - again, the current Tees have inspection caps and they also leaked. I'm happy to not have inspection caps or mess around with sealing them for underground laying, would rather re-pull the cables if and when the time comes for this in future.

The bends you should be able to get at any good electrical store, they are plenty full (you get the small ones you posted with a tight bend - almost impossible to get in there and pull a wire through, and the larger 90 degree bends which is friendly to pulling wires - I'd suggest you get the bigger ones).

The T, if used for electrical work, MUST be inspectable, because a wire joins / leaves the conduit. You won't find conduit T's without inspection joins, they won't get SABS approval.

If it's for something you want to build (i.e. not electrical), rather use 32mm water pipes. Similar to conduit, the pipe is just blue. There you will get bends and Ts and a lot of other fittings without inspection joints (because the water would obviously leak).

 

[Billy]

Thanks, will do some more looking around.



Will keep this in mind - I bought a few of those kits a few months ago for another project; think I have one left over.



Billy, what cable do you mean - I thought all underground routed wire had to be in conduit? There are max 2 bends in each run, so am interested in the cable suggestion.

Standard armoured cable with 2.5mm cores. The cable in the street is similar only bigger dia cores.

For example, my meter is in the street. An armoured cable runs from the meter alongside the drive to a connection box in the outside wall of my house to an isolator, and from there in conduit in the wall to the distribution board.

Most electrical wholesalers like Voltex sell cable by the metre. You would then need glands at each end to connect to the boxes.

http://www.aberdare.co.za/low-voltage

Page 23 on has all the details.

 

[GoB]

Standard armoured cable with 2.5mm cores.

Yea even 7 years ago I had electricians rip out non-compliant cables within conduits and replaced with armoured cable.

Including a section to my Wendy house which runs about 10cm under the lawn...

Terrible standard IMHO... don't like the idea of this one bit. I would still add conduit to prevent impact damage.

 

[howardb]

Thanks all, will look at alternatives.
I always thought outdoor underground cable HAD to be housed in conduit, but will look at the armoured cable option. Just don't like the thought of the gardener digging and hitting a non-conduited live cable...

In terms of the shallow vs tight 90 bend, I planned on pulling the cable through the conduit sections before joining/sealing and burying underground, so as to avoid the stress of pulling past the tight 90's - if sealed well, I wouldn't plan on replacing the cables anytime soon.

 

[savage]

I always thought outdoor underground cable HAD to be housed in conduit, but will look at the armoured cable option. Just don't like the thought of the gardener digging and hitting a non-conduited live cable...

Non amoured cable must be in pipes, with the exception of Surfix (round twin & earth), which can be attached to walls (not buried)... ANY cable underground (except armoured cable) must be in pipes. Most cables also also not UV protected, so a few years outside in the sun (if not in pipes), and the cable will deteriorate to such an extend that you'll need to replace it, again.

Amoured, you won't easily damage the cable. It's made to take punishment. Terminating the cable (properly) though, is not a easy and straight forward process however. Unless you have experience with amoured cable, I would strongly advise you stay away from it (the cable is also a lot more expensive). Amoured cable not terminated correctly, will not pass CoC.

Rather do a conduit and pull through a piece of twin & earth or whatever.

In terms of the shallow vs tight 90 bend, I planned on pulling the cable through the conduit sections before joining/sealing and burying underground, so as to avoid the stress of pulling past the tight 90's - if sealed well, I wouldn't plan on replacing the cables anytime soon.

And the person after you that wants to one day replace the cable and/or put more cables in?

 

[howardb]

Non amoured cable must be in pipes, with the exception of Surfix (round twin & earth), which can be attached to walls (not buried)... ANY cable underground (except armoured cable) must be in pipes. Most cables also also not UV protected, so a few years outside in the sun (if not in pipes), and the cable will deteriorate to such an extend that you'll need to replace it, again.

Amoured, you won't easily damage the cable. It's made to take punishment. Terminating the cable (properly) though, is not a easy and straight forward process however. Unless you have experience with amoured cable, I would strongly advise you stay away from it (the cable is also a lot more expensive). Amoured cable not terminated correctly, will not pass CoC.

Rather do a conduit and pull through a piece of twin & earth or whatever.

Thanks Savage, noted. May be the easiest (and cheaper) to try and cut out some tree roots and use the inspection 90's.

And the person after you that wants to one day replace the cable and/or put more cables in?

I didn't think of that! TBH the prior property owner seemed to have taken shortcuts on almost everything, so am trying to put it all right.

 

[howardb]

I eventually went with the tight T with inspection cap, sealed it up and hope there's no water ingress.

For the slip tee - ended up making these: shaved the end of the PVC pipe with a round grindstone, then cut a PVC in-line joiner in half and glue-welded it to the end of the pipe - job done.