Catenary Wire.

[slocm3105]

Hi guys, just a quickie. I'm looking to rewire a friends garage including supply to the garage. Now normally we have done this work I have supplied it with SWA underground. However this guy doesn't want his drive digging up so im going to use catenary wire. Is it acceptable to use catenary wire and simply cabel tie T+E to it as the supply? Or is there any other things I need to take into account?

Many thanks




Matt

 

[saveloy]

Personally I would use SWA on a catenary as the T+E will have no mechanical protection on its own.

 

[Dannyg83]

Agree with Saveloy , i would definetly be using S.W.A for that .

 

[Mark.W]

Agree SWA all the way...... T&E should not be exposed to the elements

 

[Des 56]

I have heard of Twin + earth being compromised by the effect of uv rays,but in many many many years of electricial installation,I have yet to witness any deterioration at all
SWA is obviously a better cable method for this type of install,but using catenary wire to support the pvc cable and complete the install without too much disruption will be fine

The darker the insulation the less effect uv light has on the cable ,so I have been told

Mechanical protection would be required if it is exposed to potential damage only

The highth at which the cateary wire is fitted will be more important with regard to damage
It is a recognised installation method Table 4A2 number 35 ref method Eor F
Dont forget the minimum highth retriction on overhead cable Table 4b on site guide

In that table, it will give you the min highths for pvc cable wiring between buildings, supported by catenary wire, typical 3.5 meters

 

[sparks1234]

Agree SWA all the way...... T&E should not be exposed to the elements

If you look in the regs it now states T & E as suitable for external use (not that I agree with that)

 

[Darkwood]

I have heard of Twin + earth being compromised by the effect of uv rays,but in many many many years of electricial installation,I have yet to witness any deterioration at all.

It does have a noticable effect especially on walls south facing but only becomes visable after 10 or 15 yrs, it was very common to find first generation pvc with u.v. damage but with the regs changing i can only assume it is now made to resist u.v. damage, if you come across it the cable will have whitened in colour from its normal darker grey and be full of fine cracks in the insulation running from the edge towards the center.

 

[slocm3105]

Many thanks guys.

So when i use the SWA can i just connect into an adaptable box inside the garage and on the outside wall of the house as I only have plastic consumer unit to connect into?

If i do this what cable sizes should i put on the EIC? I ask this because if T+E and SWA is used I'd imagine i put down the smaller cpc size of the T+E to accomodate for the worst case scenario?

 

[Spudnik]

Smaller of the two.