VAF Cable in Conduit

[Led Lolly Yellow Lolly]

Hi, read through some good posts in this electricals forum, but I need ome help.

I've wired up a house myslef, can't find anyone competent locally. I used VAF cable in flexible steel conduit in the roof and plastic conduit in the walls. The reason I chose to do this is becase the justnction boxes here have terrible sharp edges, as does the flexible steel conduit. Now I've found out there is some idiotic stupid rule here that says you can't put VAF cable in conduit! I understand there are ways around this, but what are they?

I've already downrated my circuits anyway, to take into account the VAF is in conduit, but also the soaring temperatres in the roof space. Is this enough to get around this absurd rule? My circuits are rated as follows. . .

1.5 mm cable = 10 Amps

2.5 mm cable = 16 amps

4 mm cable = 20 amps

Please advise on this because I'll be darned if I'm starting over. Have I downrated enough to please some dimwit inspector?

[Led Lolly Yellow Lolly]

Oh and one more question to add. Is there anything in the Thai rules that says I can use a CPC/Earth conductor one size smaller on final circuits? (I have RCBO fitted on main incomer). For example........

Live 6mm, Neutral 6mm, Ground 4mm

and

Live 4mm, Neutral 4mm, Ground 2.5 mm

etc etc???

[Crossy]

There is no actual rule that prohibits VAF in conduit, some PEA / MEA inspectors think otherwise but that can usually be mitigated (if you know what I mean).

If the job looks good, has a front end RCD/RCBO, a suitable ground rod and MEN wired in the manner prescribed by the Thai regs then you shouldn't have any issues.

Our PEA inspector was here for an hour, looked inside the consumer unit for 2 minutes, asked where the rod was (didn't inspect it) and gassed with the Missus for the rest of the time.

Provided you can demonstrate that your reduced CPC will open the breaker in the event of the L-E fault you'll be fine (adiabatic equation). Oops, sorry, I was thinking UK, just use the reduced CPC

This PEA document shows how to wire MEN Thai-style http://crossy.co.uk/Handy%20Files/groundwire.pdf

[Led Lolly Yellow Lolly]

Thank so much for taking the time to comment.

Do you think I've downgraded enough, or should I go further? There will never be much current on any of these circuits, I could potentially go down to a 10 amp breaker even on the plug circuits. Overkill?

[Crossy]

Have a look at this page for de-rating https://www.tlc-direct.co.uk/Book/4.3.9.htm

I think you'll be just fine with what you've suggested.

[Led Lolly Yellow Lolly]

Thanks. For the record, I've actually made this a TT system, as I can't verify 100 percent that we have a MEN supply (we're way, way out in the sticks, no village, just the family house). I asked the local PEA chap but he didn't appear to know either. If it is later established for sure to be a MEN supply, it's a trifle to add the link later, and my ground connection is 16 mm to match the incomer/tails. I can see neutral connections to ground on the pylons that run along the road, but I just feel safer with a TT system for now.