pls pls help - have my assesment tuesday 18th

[amcevoy]

Hi - i need some help. I have to install a circuit for a practical assesment and have to draw a circuit diagram 1st. The circuit is 2 2way switches and 2 lights - i can draw a diagram of 2 switches and 1 light but am confused by the 2nd light.

This is what i have to do - the work requires the following circuits to be connected to a supply within an existing trunking and tray installation

1. two - way switched lighting circuit
2. radial small power circuit consisting of four switched socket outlets
3. single radial small power circuit using steel wire armoured cable

circuit 1: the installation requires pvc single core cables installed in existing metal trunking and pvc conduit from the trunking to the luminaires

circuit 2: the installation requires 4xtwo gang switched socket outlets. These are to be connected in a radial circuit and the fourth as a spur off the middle SSO. The cabling between the CCU and first SSO is 2.5mm sq. pvc singles installed in the existing trunking with the new 20mm diameter black enameled metal conduit between the trunking and the first SSO. The remaining wiring will be surface mounted in 2.5mm sq pvc/pvc multicore cable (6242y).

circuit 3: the installation requires a 13A switched fused connection unit connected to the CCU using 2.5mm sq pvc/swa/pvc multicore cable fixed within the existing tray installation

I have to do circuit diagrams of all 3 circuits before i start.

Suitably rated over-current protection devices must be selected for the circuits and cable size where not stated

theres a 3d drawing of the installation bay as well which i will upload with this post

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• amcevoy
• 16 May 2010
• 1

and the 2 switches for the lighting circuit are marked A on the drawing and are just above the metal trunking.

Any help is greatly appreciated!

 

[wingcoax]

easiest first, the second light is connected in parallel with the first.

 

[Taylortwocities]

Have a look at the WIKI. Most of what you need is there.
But, I have to say, this is pretty mundane stuff. Surely you know how to draw a two way lighting circuit?

Why don't you have a go and draw out the diagrams for each and we can tell you if it is right. That would be more use to you than giving you something to copy/

 

[amcevoy]

ok - thanks - i thought it may pe parallel but wasnt sure. It may be mundane to some but we have had 6 different practical teachers in 2 years and missed a few lessons (bank holidays) as our course is one day a week on Mondays. In terms of practical we have not really learned very much at all and as i said i understand 2 way lighting but wasnt sure as ive never seen it done with 2 lights only the 1. Thanks for the help

 

[Steve]

This inspires so much confidence in the sparks of tomorrow.

 

[wingcoax]

In defence of the OP i have to say that modern apprentices dont get the hands on we used to do. My last one couldn't read a diagram after twelve months in a training school. 60% of his marks were on coursework.

 

[amcevoy]

Steve - your post inspires me with so much confidence - thanks. Ive worked hard for the last 2 years and unfortunately my college has let us down and im doing the best i can and will continue to do so and i already have the knowledge i just don't have the confidence to know im correct or to apply the knowledge in practical terms. Im not working in the electrical industry at the moment (this will be my next step once i get my driving license sorted) and therefore the only practical experience i have comes from a 2hr lesson once a week. I have drawn a rough diagram of the lighting circuit - would this be correct anyone?

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• amcevoy
• 16 May 2010
• 1

 

[wingcoax]

Spot on my boy. Good luck.

 

[Steve]

I wasnt neccesarily having a go at you, more your college - you should KNOW that nothing you will touch in domestic electrics is wired in series. And you should know how to duplicate connections to a light.

Your diagram - you have too many strappers. the lights will be on constantly.

 

[Steve]

Spot on my boy. Good luck.

 

[LoveRocket]

I have drawn a rough diagram of the lighting circuit - would this be correct anyone?

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• amcevoy
• 16 May 2010
• 1

No. The lamps would be on all the time.

 

[Taylortwocities]

Remove the strapper that goes between the two COM terminals.

See item 6 here //www.diynot.com/forums/viewtopic.php?t=37582

 

[amcevoy]

ok thanks alot - i only put the strapper in cos someone had wired up this lighting circuit on a board in college (minus power) and the teacher was letting us look so thought it was correct but can see how it would be wrong (the current would flow through the strapper and bypass the switches). We don't get taught much of anything in relation to domestic electrics more commercial (maybe due to the seperate part p regs - no idea) and no worries Steve - im not to happy with the college for the lack of prep and quality teaching myself and they will be hearing about it once im finished

Thanks for all your help

 

[amcevoy]

Heres two rough diagrams for the other 2 cicuits i mentioned above - any comments or help is appreciated

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• amcevoy
• 17 May 2010
• 1

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• amcevoy
• 17 May 2010
• 1

 

[ban-all-sheds]

Hi - i need some help. I have to install a circuit for a practical assesment and have to draw a circuit diagram 1st. The circuit is 2 2way switches and 2 lights - i can draw a diagram of 2 switches and 1 light but am confused by the 2nd light.

If, after 2 years, you still have so little understanding of electrics that you get confused by having to add a 2nd light to one already there (you did say you understand how to switch one light) then you should give it up.

All this talk of "we don't get taught domestic electrics", and how shambolic your practical training has been is just smokescreen b******s. A light with 2-way switching works the same way in a shop or an office or a factory as it does in a house.

2 years.

2 years of hard work and you still aren't sure enough of how a 2-way switch works not to see before you even finished drawing it that your diagram was hopeless. Never having done it in practice is utterly irrelevant, you should be able to see on paper that it wouldn't work.

When your teacher showed it to you you should have seen immediately that it wouldn't work.

2 years? It shouldn't take more than 2 minutes to learn how 2-way switching works.

You've spent 2 years trying to do something that you just are not capable of understanding - give it up now before you waste any more time, and find something you can do.

I can see me getting stick for this post, but I can pretty much guarantee you that privately everyone else is thinking the same.