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Topic Title: Terminating SWA
Topic Summary: Earth wire CSA to Earth nut or Banjo
Created On: 04 November 2009 08:25 PM
Status: Post and Reply
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 05 November 2009 06:33 PM
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OMS

Posts: 19900
Joined: 23 March 2004

I'm with Andy on this one - take a look in Part 2 - the fan is not an accessory - its an appliance or its more likley to be current using equipment.

So if it doesn't need a CPC due to saty being double insulated then there is no requirement to provide one and then park it. At the supply end yes, that would be an accessory so the CPC would be needed there

Regards


OMS

-------------------------
Failure is always an option
 05 November 2009 09:07 PM
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dg66

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I said fan enclosure which is how i read the definition in part 2 as the connections and enclosure form the accessory with the motor being the current using eqpt.

-------------------------
Regards

Dave(not Cockburn)
 07 May 2010 09:29 AM
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matt001

Posts: 64
Joined: 02 November 2009

Originally posted by: OMS

I'm with Andy on this one - take a look in Part 2 - the fan is not an accessory - its an appliance or its more likley to be current using equipment.
...


Sorry to dig up an old thread -
412.2.3.2
" Except where Regulation 412.1.3 applies, a circuit supplying one or more items of Class II equipment shall have a CPC run to and terminated at each point in wiring and at each accessory."

Would a class II fan or light be a point in wiring?

Or is it only a point if you loop out of it again (eg. class II downlights with terminal block)? In which case, how far does the CPC have to run? Up to the last downlighter in the run, or the second to last one?

Cheers.

Matt.
 07 May 2010 01:18 PM
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AJJewsbury

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Would a class II fan or light be a point in wiring?

A point can only be in the fixed wiring - so if fan was directly connected to the fixed wiring, then it'd need a CPC. But if the fixed wiring stopped at say a cord outlet plate and then there was a short loop of flex to the fan, then the CPC could stop at the outlet plate and not reach the fan.
- Andy.
 07 May 2010 07:11 PM
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SandyBoiler

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matt001 said:
Would a class II fan or light be a point in wiring?


Yes, the termination of the fixed wiring that connected a class II fan or light would be a "point" in the wiring -- see the part 2 definition of "Point (in wiring)"...looking at the definition of "Fixed equipment" I would say that "the fixed wiring" referred to in the definition of "Point" is the wiring that is "fastened to a support or otherwise secured in a specific location"...so flex could form part of the fixed wiring...

matt001 said:
Or is it only a point if you loop out of it again


No...take the last point (e.g. socket-outlet) on a radial circuit -- that is still a "point" is it not?

matt001 said:
In which case, how far does the CPC have to run? Up to the last downlighter in the run, or the second to last one?


Based on the above I'd say, "up to the last downlighter in the run"...

As an aside, I'd say it is important to take note of the note to 412.2.3.2...I'd say the only time it wouldn't be a requirement to run a cpc to a piece of class II equipment would be when it could be safely said that it would be impossible for that piece of equipment to be replaced with a piece of class I equipment...

-------------------------
Andy B

Edited: 07 May 2010 at 08:04 PM by SandyBoiler
 07 May 2010 08:15 PM
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Pactrol

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paulskyrme

Hi your comment on the oversleeving of grn/yellow to use as a phase conductor I always thought the same as you that it was a big No No
however Niceic,s book on snags & solutions advise that its ok to do as long as its a flex or multicore. ( snag 53 ) for those who wish to check
however Ive no idea if this relates to any particular Bs7671 regulation
I will have to check it out.
 07 May 2010 08:54 PM
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matt001

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Originally posted by: SandyBoiler

No...take the last point (e.g. socket-outlet) on a radial circuit -- that is still a "point" is it not?



Surely that's different? a socket is not Class II and requires an earth at all times - a class II downlighter may have no provision to terminate a CPC
 08 May 2010 01:57 AM
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SandyBoiler

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matt001 said:
a class II downlighter may have no provision to terminate a CPC


In this case, if you judge that it would be possible to replace the class II downlights with class I equipment, each downlight should have its own JB from which the final connection to each downlight is made. The supply is taken into (and looped out of, if necessary) each JB along with a cpc -- the final connection to the class II downlight from the JB wouldn't then require a cpc (the way I'd see it, the termination at the JB would be the point in the wiring and the downlight together with the final connection from the JB would be the current-using-equipment). If the downlights were to be replaced with class I downlights it would be straightforward to replace the final connections from the JBs with ones including a cpc, at the same time as the lights.

-------------------------
Andy B
 08 May 2010 07:21 AM
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matt001

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Originally posted by: SandyBoiler

matt001 said:

a class II downlighter may have no provision to terminate a CPC




In this case, if you judge that it would be possible to replace the class II downlights with class I equipment, each downlight should have its own JB from which the final connection to each downlight is made. The supply is taken into (and looped out of, if necessary) each JB along with a cpc -- the final connection to the class II downlight from the JB wouldn't then require a cpc (the way I'd see it, the termination at the JB would be the point in the wiring and the downlight together with the final connection from the JB would be the current-using-equipment). If the downlights were to be replaced with class I downlights it would be straightforward to replace the final connections from the JBs with ones including a cpc, at the same time as the lights.


What makes you think an average person would undo the JB, remove the cable and prepare a new one with an earth connection? I think they'd be more likely to just disconnect the old downlighter from the incoming cable and swap that.

Besides, that's a lot of extra work ...
 08 May 2010 01:28 PM
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SandyBoiler

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matt001 said:
What makes you think an average person would undo the JB, remove the cable and prepare a new one with an earth connection?


Well at the end of the day class I fittings come with instructions saying they must be connected to earth -- whether someone bothers to read/follow those instructions is another matter. All I said was, with the JB arrangement you have made it straightforward to connect replacement class I downlights to earth so you have done your bit as the designer/installer + you may have done yourself a favour if the customer suddenly decides they want some fittings which are class I.

-------------------------
Andy B
IET » Wiring and the regulations » Terminating SWA

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