Am2 Lighting Circuit Fail

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Nikolay

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I failed lighting circuit at AM2. I had intermediate switching with trunking plastic switches ( 2x two way switches, 1x intermediate switch) in plastic conduit boxes using 6242Y and 6243Y cables and round celling light with strip connectors. 

   Everything worked. Question is not about how to connect correctly switches.

   I feed supply cabe to first intermediate switch. Using strip connector connected neutral and send it to light with earth and L2 from switch. In each switch i connected earth with strip connectors as well. I cannot figure out there is my mistake. 

1) I couldn't find any earth connections on plastic switches and plastic conduit boxes ( Should I be looking for plastic terminal connection block somewhere) or screw on plastic switch?

2) Even if drawing sad to feed switch from DB. Should instal one cable straight to light and then using strip connection send phase to first switch ?  To avoid having Neutral in first two way switch. I seen as well that people send neutral and earth to light and second cable from DB to first switch. But it will mean that  1 conductor of each cable not used and strip connector needed on each end?

It might be something to do with earth or neutral connection in switch i don't know really.

Please help me to identify my mistake. 

Thank you very much.

http://postimg.org/image/dk3wjydon/

 
Perhaps you could draw out how you wired it? 

If there's no earth terminal in the box, nothing wrong with using a connector block for the earth.

Could they not tell you why it failed? most unhelpful if they don't.

There are plenty of ways of wiring light circuits, loop at switch, and loop at light are the most common. Neither is right or wrong, it's often down to preference or building layout which works best, other than generally avoid loop at light if you are using downlighters.

 
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Thank you Dave. I wired same way as here http://postimg.org/image/dk3wjydon/ . I did functional switching and all worked.  I could find any earth terminal on plastic switch itself.  Mistake i made might be  than i feed phase to L2 instead of L1 on first two way switch, but it doesn't make sense switching wise. 

I will try to contact AM2, but according to this link http://www.netservices.org.uk/am2_after_your_assessment.html

Failure to qualifyUnsuccessful candidates are those whose results indicate that they have ‘failed to achieve the required standard’ in one or more sections.

In this case, the candidate is required to re-sit each full section in which they were unsuccessful. 

  • NET cannot assist directly with enquiries regarding results; all queries must be directed to the centre where the assessment took place

  • Unsuccessful candidates will only be notified of which part/s of the assessment they have failed, and will not receive ay more information than this

  • Note that AM2 examiners will not know whether a candidate has passed or failed, and cannot advise at the point of the assessment. This is because the marking system is independent of the assessment centre

  • All AM2 centres accept bookings for re-sits. To book a re-sit of one or more AM2 assessment sections (or the entire assessment) please contact your preferred AM2 centre directly.
  •  
 
It was round celling light with connector block for N,L,PE. There was no celling rose. So as drawing says I send cable from DB to switch and from switch to light. 

 
If you have wired it to that diagram I can't see what's wrong.

Was it the standard of workmanship? wires stripped too far exposing bare conductors? insulation nicked etc?

Was it wired in conduit and they expected you to use singles rather than 6242Y etc?

Telling you that you have failed but not telling you why is not exactly helpful. Imagine if you failed your driving test without being told why.

Can you tutor not shed any light on what the problem was?

 
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Thank for you reply Dave.

I will try to contact AM2 centre for further update at Monday and give any update. 

I will do composite installation again next weak. 

It might sound silly but do you make double over termination of conductor then you terminate more than one wire in connection? let say two two wires under one switch connector?

Usually then terminating flexible single conductor we do double over connection.  For  6242Y  i don't have to do double over because it is solid conductor. 

I remember i put a sleeve on earth plain conductor and brown tape on each L conductor connected to switch.

I put a bit brown tape around on the cable PVC main insulation.  So i secure beginning of cps sleeve. 

 
I did the same and never had any feedback regarding why, i was sure it was correct and how they wanted it wiring. I wired it the exact same as in the picture uploaded, hopefully someone can help. 

many thanks

Ash

 
I failed lighting circuit at AM2. I had intermediate switching with trunking plastic switches ( 2x two way switches, 1x intermediate switch) in plastic conduit boxes using 6242Y and 6243Y cables and round celling light with strip connectors. 

   Everything worked. Question is not about how to connect correctly switches.

   I feed supply cabe to first intermediate switch. Using strip connector connected neutral and send it to light with earth and L2 from switch. In each switch i connected earth with strip connectors as well. I cannot figure out there is my mistake. 

1) I couldn't find any earth connections on plastic switches and plastic conduit boxes ( Should I be looking for plastic terminal connection block somewhere) or screw on plastic switch?

2) Even if drawing sad to feed switch from DB. Should instal one cable straight to light and then using strip connection send phase to first switch ?  To avoid having Neutral in first two way switch. I seen as well that people send neutral and earth to light and second cable from DB to first switch. But it will mean that  1 conductor of each cable not used and strip connector needed on each end?

It might be something to do with earth or neutral connection in switch i don't know really.

Please help me to identify my mistake. 

Thank you very much.

http://postimg.org/image/dk3wjydon/

hi there.

you should connect the permanent feed to the first 2 way switch not intermediate, as the diagram tells you

you did not screw the earthing cable into the plastic box/switch.......hahahahaha....sorry.

are you sure it was the lighting, or just the lighting

I have to take this exam in the summer, and the way I would do it, is to feed the closest switch to the light (2 way). considering that you using twin&E / triple&E its easier to carry the neutral to the light and back  to the c.u 

 
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Lighting circuit is wired as follows: feed to switch 5 [6242y],[ feed to light from switch 5 6242y], then 3core and earth [6243y] between switches 6 and 7. CPC terminations and any others within switch back boxes must be completed with screwless connectors.Donot forget table 51 eg colours for all line conductors [brown].

All info is on drawing 1 in your test rig and also in your candidate info book also in your rig.

Best of luck to all new candidates.

 
Lighting circuit is wired as follows: feed to switch 5 [6242y],[ feed to light from switch 5 6242y], then 3core and earth [6243y] between switches 6 and 7. CPC terminations and any others within switch back boxes must be completed with screwless connectors.Donot forget table 51 eg colours for all line conductors [brown].

All info is on drawing 1 in your test rig and also in your candidate info book also in your rig.

Best of luck to all new candidates.
Are you a tutor ?

This may be the way AM2   want it done but out in the real world that is not needed, screwed connections are acceptable. The drawing  does show feeding a 2 way switch, not the intermediate but again, in the real world you do it to the easiest and most economical way as its not any regulation.  In my days of training you always had to fix connectors to the enclosure. MK used to sell the earth terminals separately which we would fit in the back of plastic boxes. All other connectors were self tapered or nut & bolted down. All terminations always had to have the ends doubled over and stranded cable twisted, Never twist together solid core cable. You should not be able to see or touch any bare bit of the cable . All this was good workmanship & not necessarily the regulations

 
Tutor yes for 36 yrs another 6 yrs as a assessor for can't say who for!!!!. The real world and NET are so far apart; will they ever meet I think not. So to pass your assessment do as they say and when passed do as your boss says.

 
"Usually then terminating flexible single conductor we do double over connection"

Flexible cables should have ferrules....It says in the regs somewhere about "suitable treatment" for the cable ends, [soldering not allowed!]

john..

 
Lighting circuit is wired as follows: feed to switch 5 [6242y],[ feed to light from switch 5 6242y], then 3core and earth [6243y] between switches 6 and 7. CPC terminations and any others within switch back boxes must be completed with screwless connectors.Donot forget table 51 eg colours for all line conductors [brown].

All info is on drawing 1 in your test rig and also in your candidate info book also in your rig.

Best of luck to all new candidates.
Isn't that how nikolay had wired it though??? going by the link to the diagram he quoted it seems the same as yours.http://postimg.org/image/dk3wjydon/

 
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