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# One Way Lighting Circuit

Discuss One Way Lighting Circuit in the Industrial Electrician Talk area at ElectriciansForums.net

B

#### Bane

Welcome to ElectriciansForums.net - The American Electrical Advice Forum

Hello people.

Well, for my homework, I've been asked to research one way lighting circuits.

On google I've come across a number of sites and not many on wikipedia.

Anyway, seeing as how we haven't even covered lighting circuits at college yet I found this a bit poo. I digress, sorry.

Can someone please explain to me a one way lighting circuit in relatively simple terms?

Cheers.

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#### ian.settle1

##### -
Mentor
Arms
Bane,

A one way light circuit is basically one switch to switch the light on.

A two way is where the are switches at different locations switching the light on.

You can also fit intermediate switch on the strppers so you can switch light on at three or more location depending how many intermediate switches are fitted.

Hope this helps you out.

May not get much info about switches on wikipedia as you will find it an American website.

B

#### Bane

Ah. Ok.

Very simple and the answer was quite easy too!

Thanks Ian.

S

#### spark-doctor

Have a look at this

B

#### Bane

Not understanding that diagram Spark-Doctor.

Phase=Live?
CPC= Earth?

Red sleeving indicates that the neutral becomes a live also?
If yes, then why red sleeving and not brown?

S

#### spark-doctor

And to get you ahead of the others

Sorry mate. It is a old picture. Look at this one ond all will be clear.

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B

#### Bane

Ok, got that thanks mate.

One thing. What's going on in the top right corner of the diagrams, where they are circled?

Sorry, but I like to know all the ins and outs, I can't just accept things.

G

#### GAZHUDDS

The circle bit represents the light fitting

S

#### spark-doctor

The circle is showing the ceiling rose with the termination points.

Just to add. These pictures are showing the wiring in T&E. If you were to wire it in singles through conduit you would be able to run the correct color wiring and would not need the sleeving. The wiring diagram would be the same though.

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B

#### Bane

So where are the cables going from the fitting to the left of the page?

G

#### GAZHUDDS

There coming from the consumer unit or another ceiling rose in the circuit.

S

#### spark-doctor

To the consumer unit/fuse.

B

#### Bane

Cheers Gaz, cheers Ian, cheers Ian (Spark).

I'll be extra clever and throw in the 2 way too!

H

#### heathelect

There either going to or from the next light or from the consumer unit. Hope that helps, dave

B

Thanks Dave

S

#### spark-doctor

If you wanted to add another lamp to the circuit, just run another piece of T&E from the ceiling rose to another lamp. Connect the new neutral to the existing neutral. The new phase to the switched phase (the one with the sleeving and the new CPC to the existing CPC This is called the "loop in method"

B

#### Bane

Loop in method. Ok.

And the cable used is T&E 2.5mm? 1.5mm?

Phase is Live?
CPC is Earth?

Getting to grips with terminology too.

#### ian.settle1

##### -
Mentor
Arms
Loop in method. Ok.

And the cable used is T&E 2.5mm? 1.5mm?

Phase is Live?
CPC is Earth?

Getting to grips with terminology too.

1.5mm for lighting
2.mm for sockets

S

#### spark-doctor

Loop in method. OK.

And the cable used is T&E 2.5mm? 1.5mm?

Phase is Live?
CPC is Earth?

Getting to grips with terminology too.
Generally lighting circuits are in 1.0mm T&E, socket circuits are in 2.5 T&E.

Try to get out of the habit of calling the Phase live and the CPC earth especially the later. They have different meanings as you will find out in the next few weeks

B

#### Bane

Thanks guys.

So in T&E you have:

Neutral
Phase
CPC = Circuit Protective Conductor (Earth sleeving?)

Correct?

Finally, in the diagram we'll have 1.5 going into the light fitting from the CU and 2.5 coming down to the switch?

G

#### GAZHUDDS

no you would wire all the circuit in 1.0mm or 1.5mm

B

#### Bane

Right.

Last week at work I'm sure we did all the lights in 1.5 and switches in 2.5 (Or vice versa).

W

#### wayne

shouldn't change cable size unless goihg through a fuse/mcb ...unless the original CPD is rated small enough

one way switching; from the source(mcb/fuse) to a switch through the sw to the light .neutral taken direct to the light .

17th edit is line not live

just thought i'd join in

B

#### Bane

Cheers and Hi Wayne

Can someone explain to me then, why the N becomes Live in one way then, when converted to 2 way. There is effectively 3 Live wires???

S

#### spark-doctor

You only need to switch the line/phase wire, so you use the neutral wire as a return path from the switch to the lamp.

A

#### andy8758

Hi Bane - After reading this thread - is this an obscure wind-up? Are we really discussing how one-way and two-way switches work?

Doesn't everyone know the IEE change the name of the 'Live' every 5 years to keep everyone on their toes? As we move from Phase to Line I understand that for the next version of Regs we will be calling it "Le Bang" apparently part of European Harmonisation.

OK Bane, maybe you are a student, but I thought wiring lighting circuits was covered in week 1 of your apprenticeship? Meanwhile the other guys have given you the answer so I guess I shouldn't take the mickey any further.....

lol!

G

#### GAZHUDDS

The black cable that is going to the switch is not a neutral its the switch wire or one of the strappers. By the way a neutral is always considered a live cable thats why we use terms like 'phase' conductor, remember that for college

B

#### Bane

Andy8758? Yes, the moon really is made from cheese.

GAZHUDD. Cheers for that

Is the Neutral always the return path then?

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G

#### GAZHUDDS

The neutral is the return path from the load in this case the light fitting.

B

#### Bane

Got it.

Power comes down the Phase.
I press the switch.
Power returns via the N (hence the sleeving) and powers the lamp.

Phew! Now, let someone tell me that's wrong

P

#### PAUL M

its not called the phase anymore mate it is now the LINE conductor.

G

#### GAZHUDDS

You only need to switch the line/phase wire, so you use the neutral wire as a return path from the switch to the lamp.

Thats not a neutral wire then, Bane try to forget what colours the wires to the switch are. At the moment we would use a twin brown or single brown at light switches.

S

#### spark-doctor

My fault. Old habits die hard

B

#### Bane

MY BRAIN IS MELTING!!!!

Only joking. Got that.

Cheers guys for all your help. Much appreciated.

Will let you all know how I get on tomorrow.

Off to watch C4 now!

Night guys, thanks again.

R

#### rumrunner

Got it.

Power comes down the Phase.
I press the switch.
Power returns via the N (hence the sleeving) and powers the lamp.

Phew! Now, let someone tell me that's wrong
Hi Bane
THats wrong ,think of the nuetral being on one side of the resistance ,in this case a lamp ,and the lives or line whatever on the other,the switch has a live and switched live ,known as a switchwire ,
so neuitral to light ,live to switch ,live return from switch all wired in 1mm or 1.5
hope this helps

H

#### heathelect

hi bane, dont worry about not understanding 1 way lighting circuits i was the same when i was an apprentice, then one day it clicked and i thought what a thick bugger i must off been, never mind 30 odd years on i can now do 2 way and intermediate circuits,(how clever am i ?), no sarcy comments from anyone thanks, regards dave

S

#### stevie h

Got it.

Power comes down the Phase.
I press the switch.
Power returns via the N (hence the sleeving) and powers the lamp.

Phew! Now, let someone tell me that's wrong

your on the right track here , but forget about black being N , its live , ...

lighting may take time but it will all click into place eventually

S

#### sparkyork

yeah i striggled with it at first just on a simple one way lighting circuit, i just couldnt get it in me head! then as beens said you wake up one morning and it all becomes clear, then you gotta get your head round 2 ways and intermediates!

to be honest as some of you lot know i sometimes come across like i know bugger all, and i still cant get me head round using singles and twins for 2 way lighting (only cos i choose not to wire that way tho!!)

B

#### Bane

Hello everyone,

Well, first and foremost, a BIG THANK YOU to EVERYONE who posted advice, diagrams and explanations for little ol me.

However!

We didn't even get them checked out today! Ar*ewipe tutor neglected to give us timetable which would have consequently shown that today we actually had First Aid all morning and no workshop

Not a happy mouse!

So...We'll no doubt be covering 'one way' next week so, again, will keep you all posted on that one and in the meantime I'll be badgering my poor old mentor as from tomorrow about what he knows!

Thanks again guys.

T

#### trebor73

Hello everyone,

Well, first and foremost, a BIG THANK YOU to EVERYONE who posted advice, diagrams and explanations for little ol me.

However!

We didn't even get them checked out today! Ar*ewipe tutor neglected to give us timetable which would have consequently shown that today we actually had First Aid all morning and no workshop

Not a happy mouse!

So...We'll no doubt be covering 'one way' next week so, again, will keep you all posted on that one and in the meantime I'll be badgering my poor old mentor as from tomorrow about what he knows!

Thanks again guys.
BANE!!! You're a STUDENT???? Come back when you are qualified to call me "stupid man".

Cheers.lol

S

#### Shakey

Hello everyone,

Well, first and foremost, a BIG THANK YOU to EVERYONE who posted advice, diagrams and explanations for little ol me.

However!

We didn't even get them checked out today! Ar*ewipe tutor neglected to give us timetable which would have consequently shown that today we actually had First Aid all morning and no workshop

Not a happy mouse!

So...We'll no doubt be covering 'one way' next week so, again, will keep you all posted on that one and in the meantime I'll be badgering my poor old mentor as from tomorrow about what he knows!

Thanks again guys.
ruddy hell Mr Bane, been busy and missed all that thread, could have just sent you might lighting teach!

sorry mate, i'll try and stay on the ball

B

#### Bane

BANE!!! You're a STUDENT???? Come back when you are qualified to call me "stupid man".

Cheers.lol
Well Trebor73, evidently you ARE stupid for making the presumption that I was... Well, I don't know what you assumed I was but, a quick read through my posts would have made it sufficiently evident that I am in no way, shape or form, qualified.

Thanks for posting in my thread though.

ruddy hell Mr Bane, been busy and missed all that thread, could have just sent you might lighting teach!

sorry mate, i'll try and stay on the ball
Not a problem Mr.T.

I'm very confident that you will be more than helpful in any future situations that shall arise.

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S

#### Shakey

Well Trebor73, evidently you ARE stupid for making the presumption that I was... Well, I don't know what you assumed I was but, a quick read through my posts would have made it sufficiently evident that I am in no way, shape or form, qualified.

Thanks for posting in my thread though.

Not a problem Mr.T.

I'm very confident that you will be more than helpful in any future situations that shall arise.
no problem Mr C, ask away

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