Running T&E in conduit

[parm]

Hi Guys,

I've been asked to do a surface mounted ring mains in a residential property, is it normal practice to leave the wires loose in the conduit or would you tie wrap them together or use something else? Thanks in advance from a newbee

 

[Amp David]

Keep then loose then if one need pulling back in the future you're OK

 

[Hawk81]

Tie wraps will only make it difficult to get the cables down the conduit. leave them loose.

 

[Sintra]

Agree always leave cables untaped in conduits.

 

[parm]

Thanks to all of the above guys

 

[malcolmsanford]

Are you really running T & E or was that a miss post. Also if you haven't done it before wiring a ring final circuit in conduit takes a bit of thinking through as you need to get your return leg back, I assume through the same outgoing conduit.

A way was pull 1st leg into 1st socket, 2nd leg into 2nd socket, 1st then to 3rd, 2nd to 4th etc using the boxes as pull throughs

 

[Guest123]

As it's a residential property I'm guessing he means mini trunking for the drops???, otherwise it'll be a bit of a job pulling through conduits.

 

[malcolmsanford]

I wouldn't fancy 4 x 2.5mm^ in conduit..............

 

[parm]

unforunately its going to be the entire ring in conduit, customer doesn't want boards up!! not looking forward to it, may see if I can suggest using slightly bigger conduit

 

[malcolmsanford]

boards up??

 

[m4tty]

That's gonna look nice mate conduit running around the living room. Lol

 

[parm]

I know, glad its not my place.....landlord decorated before getting PIR may take a picture and pop it on the site

 

[millwall ken]

Why would you pull T & E cables though Conduit? What about heat dissapation? The BRB states that the capacity of Trunking/Conduit should not exceed 45%.

 

[parm]

OSG and BRB state 45% space occupancy for heat discipation for single core cable which I agree with, however running 2.5mm thorugh conduit (2legs) will give a cable factor of 143 and I was planning to ussing 50x38mm conduit which has a factor of 767. So I suppose as my calculation is not strictly speaking correct, I thought around a 20% space occupancy for T&E would be fine....happy to be corrected

 

[Guest123]

As I suspected......you are referring to square/oblong mini trunking with a base and lid, as opposed to solid round conduit (pipe).

 

[parm]

Yes I am referring to the square trunking with the lid, apologies for not being clear

 

[Guest123]

So to clarify, are you running cables through the floorspace with the vertical drops to socket outlets in surface mini trunking???

If so the usual size that is used for a drop containing 2 x 2.5mm T&E's is known as MT2 which is 25x16mm in size.

 

[parm]

Thank you for clarifying the trunking size Lenny.........being very conservative by having larger conduit for heat discipation. Another newbee question bites the dust, thank you again

 

[martysparky]

do you mean this

Miniature trunkingRapid Electronics - Cables & Connectors > Cables

or this

PVC Conduit Round Light Gauge - 20mm x 3M - White - QVS Electrical Supplies | Electrical Wholesaler

 

[martysparky]

gosh missed that lol