Wiring lights in singles.

[smity]

Hi folks.

when wiring lights in singles does your earth and neutral have to take a specific path or does it just need to be at each fitting. For example

1 circuit feeding 3 PIRS and each PIR feeding 5 fittings. Would you

A- take a LNE to each PIR then take a separate a SW/L NE to the fittings from each PIR

B- take your PERM L to each PIR then wire your neutral and earth continuous through the first PIR then 5 lights then Next pir and so on and then a SW/L from the PIRS to fittings so as to keep the NE continuous?

Or am I over thinking things? Just trying to think of the end of line as in method b you may not have a proper end of line at the last fitting as the perm live would end at the pir.

Thanks

 

[Pete999]

1 line and Neutral for each circuit, wired in plastic conduit I presume?

 

[smity]

Metal conduit, yes 1 circuit thanks

 

[Plonker 3]

Take a CPC to each point and neutrals only to where they are required, obviously using routes that will not create eddy currents.

 

[Adam W]

Take a CPC to each point and neutrals only to where they are required, obviously using routes that will not create eddy currents.

Is there some sort of rule of thumb for doing that? I'd never really thought too much about it before.
I mentioned it once and some old spark said you don't need to worry about Eddy currents if there's a neutral with the lives - is this right?
Also how would you go about wiring a large switch panel where you need multiple tubes going into the same enclosure?
You could spread all the phases across all the tubes, but then surely the situation could exist where the lights from one phase going through one tube are switched off and only the lights from another phase in another tube are switched on, generating eddy currents?

 

[Lucien Nunes]

I.e., neutrals should take the same routes as the lines they serve. If you have one spine of conduit with branches, you can run one N all the way along looping in at whatever points it needs to visit. There's no need to branch the cables too. If there are closed loops of conduit, don't draw the N to a given point round one way and the L round the other.

I made this mistake when doing my first steel conduit experiments aged about 13, fed some fluorescents with unpaired cables and caused hellish AM radio interference until I worked out what I had done.

 

[DPG]

Is this plastic or metal tubing though? Daz

 

[smity]

Thanks for all replys.

I think I was thinking in twin.

So if I wanted to feed two PIRS in trunking one at both ends of a room first one Switching first 4 lights lights and the Second switching the next 4 lights i can feed first PIR then I can pick up the lights with the N and E on the way to the last pir then wire the SW from the pir's to the fittings I want them to switch

 

[Lucien Nunes]

Yes, it's the same as making a switch drop with a neutral from a 3-plate rose.

 

[shanky887614]

no need to take neutrels to the switches though and no need to take one in conduit except at fittings/pir's