Conduit and Earthing Cables

[rjuk]

I'm wiring up a new garage in PVC conduit.

I'll be running three circuits down one piece of conduit and I was wondering if it was acceptable for them to share the same earth cable (rather than running 3x2.5mm2 - simply running a single piece) in an effort to comply with the cable capacity of the conduit?

I'm also going to be running some DC control cables in the garage - are the core colours for DC brown/blue or did they remain red/black?

Thanks in advance,
Ryan

 

[breezer]

no you can not use one earth wire for 3 ccts, and yes dc is red and black, you should not run dc with ac

 

[plugwash]

hmm I was sure there was a reg that allowed it provided the earth wire was sized to meet the requirements for all the circuits.

 

[holmslaw]

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[shetland]

Unearthed DC power circuit new colours Brown and Grey
Negative earthed DC power circuit Brown and Blue

 

[Spark123]

From Table 51 (BS7671:2008)
For control circuits, ELV and other applications. Line conductors Brown, black, red, orange, yellow, voilet, grey, white, pink or turquoise.
For a neutral or mid wire blue (an earthed PELV conductor is blue)

 

[holmslaw]

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