Bit of an exam question!!!

[voycie]

Hi All,
I've been left with a first-fix lighting circuit I need to finish up. It has three zones A, B and C. There are 2 switches: a single, double and triple -they operate the zones as per the diagram below.

Each switch has the following wires going to it. All are 3 core and Earth apart from the the 2 core and earth to the left switch. Zones A and B should be easy to do, but what about zone C? Why are there two 3 core and earth cables on the right-hand switch? Does one of these take a permanent live off the switch for zone C?

Any thoughts much appreciated.

 

[securespark]

If you don't know, how are we supposed to???

It depends how it has been wired, whether 3c&E cables have been used instead of 2c&E, and a whole host of other factors.

Bell them out!

The only comment I would have is that the r/h switch "B" is an intermediate.

Didn't you ask your lecturer for some hints?

 

[comms]

are you sure that the left hand 2g switch(B) isnt 3c+e, that would then make zone B controlled by 2way & inter switching.

Then the 3g switch (C) has the T/E making one way switch for zone c.

 

[jj4091]

As Securespark says, I would think the R/H switch is an intermediate for zone B,plus switch C would just utilise 2 cores for a 1-way cct. & you are a cable short to be able to connect zone A as a 2-way

 

[voycie]

sorry, the cables arn't above any particular switch in the diagram, Actually, on the left hand switch, the 2c+E supplies Zone A. The remaining 3c+E cables are presumably to run up to the uppermost switch in the diagram for the 2-way switching.

Agreed that the R/H switch is an intermediate.

Does that help?

 

[jj4091]

sorry, the cables arn't above any particular switch in the diagram, Actually, on the left hand switch, the 2c+E supplies Zone A. The remaining 3c+E cables are presumably to run up to the uppermost switch in the diagram for the 2-way switching.

Agreed that the R/H switch is an intermediate.

Does that help?

In that case you are short of a cable to supply zone b

 

[voycie]

both zone A and B already are live - the 2C+E on the left hand switch works the lights in zone A, and one of the 3C+E's on the top switch works the lights for zone B. I dunno how to get zone C lit up though!!

 

[jj4091]

voycie, I think you are getting a little confused,or you are confusing me,look at the wikki for 2-way lighting ccts.

 

[voycie]

Yep I'll do that. THe confusion for me lies in not understanding how zone C is going to get power to it based on the circuit I have. Thanks for the input though, and yep I'll take a look as you say. Ta.

 

[mst]

youve all lost me

 

[securespark]

That makes a change. It's usually me!!

 

[tim west]

sounds like a 2 way lighting conversion method to me.