50mm ducting ?

[masona]

The Hot Tub company want me to put in a 50mm Black High Impact Duct in the ground at 450mm deep for their cable, so far I cannot see anywhere for availability, can you help me on this one ? I must admit I've not heard of 50mm ducting.

TIA

 

[Big_Spark]

Masona, ducting can be a nightmare to get hold of, an acceptable alternative is 50mm or 100mm water/soil pipe.

 

[AdamW]

50mm ducting? They must want their water ever so bubbly to require a duct for such hefty wiring! Must be one of those new megawatt rated hot-tubs?

Sounds like a good idea though. Especially if they want the option to have additional cables running through there later on. What is the noise-shielding of SWA like? Could you run shielded speaker cables through the same duct without getting all manner of 50Hz hum and transients from the pump motor switching?

Structured wiring for the garden, whatever next!

In terms of using pipe for ducting, I used a short length of 40mm solvent weld (i.e pretty tough) waste pipe as a neat way of running a thick bunch of cables straight through a stud wall. I holesawed a hole just big enough on each side of the wall, slotted the pipe through and glued it in place, slightly proud of each wall surface then used filler to give a radius on the joint before decorating. Certainly looks neater than just a hole in the plasterboard with cables shoved through, and saves the plasterboard from getting ripped about by the cables when new ones are added.

 

[masona]

Masona, ducting can be a nightmare to get hold of, an acceptable alternative is 50mm or 100mm water/soil pipe.

Properly be best to use the glue solvent type waste pipe to prevent water getting in or doesn't it matter ?

50mm ducting? They must want their water ever so bubbly to require a duct for such hefty wiring! Must be one of those new megawatt rated hot-tubs?

No, It's only a 13amp cable ! Maybe a Multi-flex cable, I don't know yet.
I was sursprise when they're asking for 50mm ducting, I wonder if they have a moulded 13amp plug type that need to go through 50mm ducting ????

Copy & paste from my old post below as I'm starting this tomorrow !

My electrician is still ill at the moment but will check my work before final connection.

Hopefully the last question !

I have bought a 4 core SWA to use only one single run out and incorporate both parts of the ring in one cable. My electrician was saying you shouldn't really use the outer steel wire sleeve as a earth cable as it could give a poor connection due to corrosion on the nut gland as it really is for mechanical protection. He advise me to run another 2.5mm Earth cable along with the SWA (any comment ?) if so do I connect the earth cable into the gland nut where the steel wire is or drill a hole underneath the socket and make a earth connection there ?

The sockets are internal with metal casing type.

 

[breezer]

I would use the armour as earth

 

[masona]

I would use the armour as earth

Thanks, so an extra earth cable not really needed and a bit over the top ?

 

[breezer]

your electrician thinks not, so long as you use proper glands i can not see it being a problem

 

[plugwash]

you can use the armour as earth but doing so has a couple of issues

1: with larger sizes earth loop impedence can be a pain if you do this especially over longer runs

2: if a cable gets ripped out of it's gland the inner cores can easilly stay connected while the armour disconnects

 

[masona]

your electrician thinks not, so long as you use proper glands i can not see it being a problem

My electrician who's now retired and was a oil renfinery electrician and perhaps they have there own strict rules and regulations over there.

 

[Big_Spark]

I would use the armour as earth

That would normally be the way of dealing with an internal instalation, however he said he will come into the back of the CU from inside the wall, so terminating in a gland may be problematic and the earth copuld become compromised, hence the 3 core recommendation.

 

[masona]

Okay, sound like a grey area, as I already bought the 2.5mm Earth cable so I will run it along with the SWA cable as a further protection. Instead of drilling into the bottom of the socket for the earth cable, I suppose I could use the Earth tag on both side of the gland nut ? ( 1 inside the socket and 1 outside of the socket ).

 

[breezer]

( 1 inside the socket and 1 outside of the socket ).

one at each end if you insist, not inside and out of the same box, how is a cable going to get ripped from its gland? cable should be fixed at regular intervals

 

[masona]

Thanks lads........

 

[Big_Spark]

Ignore my earlier post...it is in the wrong thread?

 

[ban-all-sheds]

Sounds like a good idea though. Especially if they want the option to have additional cables running through there later on. What is the noise-shielding of SWA like? Could you run shielded speaker cables through the same duct without getting all manner of 50Hz hum and transients from the pump motor switching?

Not allowed, unless the speaker cables have 230V insulation.