Trunking Q

[rick]

Typical ... having built a new house found I need some cable where I didn't allow for it ...

Thinking of putting in Solar pv panels so need to get feed in cable from loft down to consumer unit. I can drop down to garage - so can easily run this across boarded face of garage ceiling ... I also intend running in 2 extra lengths of CT100 (and multi core DC cable) to go to outbuildings for CCTV ... which I could also route across garage ceiling.

(Ceiling is boarded, on counter battens, fixed to silent floor joists, think it would be very difficult to try & feed cables above the board. )

I have never mixed power & non-power in same trunking ... what is the ruling ?

Can you get small trunking ( eg 25 x 38 wide) which has a centre rib separating halves ?

I could run twin 20mm conduits .. just thought a single trunking be easier

[Malcolm Race]

Put small trunking inside larger trunking. TLC has a good range for an idea of sizes - some available without a cover

Malcolm

[harry]

You aren't allowed to install your own PV panels (at least if you want the FIT payments) You have to get in a registered installer. So forget about it.

You will need a site for the grid tie inverter. Wants yo be somewhere cool, dry and dust free ideally. NOT in the loft.

If running cables of different voltage in one conduit/trunking, they all have to be insulated to the higher voltage standard. Signal cables and mains in one trunking is a bad idea, leads to all sorts of interference problems.

The DC voltage from the PV panels can be around 800 volts. Depending on how they are wired.

[Peter Johnson]

Why not in the loft? My inverter was installed in the garage roof about three years ago and none of the electricians who've seen the installation since have made any comment about it.

[Dave Liquorice]

somewhere

Have you ever been in a loft in the middle of the day summer with the sun out from spring to autumn?

They get rather warm, as the sun is out the invertor will be working hard, it has losses as heat. To lose that heat it has to be hotter than ambient by say 40 C, If the loft is push 40 C that means the invertor is 80 C. That is getting rather hot for electronics to remain reliable and give full life.

Is that space as well insulated as a house loft should be? or open to the unheated well ventilated garage below?

[harry]

All electronic stuff is more reliable/longer lived in a cool place.

[ARW]

+1

[rick]

That was my plan B .... thanks guys confirmed approach

[rick]

The feed-in inverter & meter will be in my garage by CU ... hence need to route cable there. Considering a system with per panel optimizers.