C.P.C in T&E as a live conductor

[leep82]

I know the thread title sounds bad but hear me out. I have wired an intermediate switch set up with feed at one switch, switch wire at another and twin and earth as my strappers between to an intermediate switch. My customer wishes to use lightwave switches for the three posistions mentioned where originally he didnt.

Im only a little familiar with the lightwave stuff having used it on other areas of the customers property. The problem that now seems to face me is that, how i understand it anyway, the three lightwave switches all need a permanent feed, a switch feed and a signal cable between them. This isnt a problem at two of the switch positions but at the third i only have one twin and earth ( strappers ) and my switch feed to the lights.

Reading up on the lightwave stuff it states that the signal cable between the three must not have mains voltage applied to it and operates on low voltage. With this in mind im wondering if i could get around the issue by using the cpc as the signal cable between two of the switches.

No accessories will be left without a c.p.c as there are other c.p.c’s present. I know its not ideal and im not fully comitted to the idea. If the signal cable required mains voltage i would NOT even consider this approach. Would appreciate any opinions

 

[ipf]

Obviously there are a few issues. I presume when you say low voltage you mean extra low. Separate voltages in one cable, bare cable, marking and labelling, future work being carried out, etc......BUT....if you feel happy from a safety point of view, I can't see any real problem in such a situation. I'd go for it, if content.

 

[westward10]

Whilst the bare core is acting as a cpc it requires no insulation, as soon as you change its purpose by applying a low voltage through it it requires insulating to the highest voltage present, that being 230 throughout its length.

 

[Pete999]

I know the thread title sounds bad but hear me out. I have wired an intermediate switch set up with feed at one switch, switch wire at another and twin and earth as my strappers between to an intermediate switch. My customer wishes to use lightwave switches for the three posistions mentioned where originally he didnt.

Im only a little familiar with the lightwave stuff having used it on other areas of the customers property. The problem that now seems to face me is that, how i understand it anyway, the three lightwave switches all need a permanent feed, a switch feed and a signal cable between them. This isnt a problem at two of the switch positions but at the third i only have one twin and earth ( strappers ) and my switch feed to the lights.

Reading up on the lightwave stuff it states that the signal cable between the three must not have mains voltage applied to it and operates on low voltage. With this in mind im wondering if i could get around the issue by using the cpc as the signal cable between two of the switches.

No accessories will be left without a c.p.c as there are other c.p.c’s present. I know its not ideal and im not fully comitted to the idea. If the signal cable required mains voltage i would NOT even consider this approach. Would appreciate any opinions

Something I wouldn't contemplate doing, not sure which regulation it breaks, the cpc will not be insulated throughout it's length, or something to that effect, sorry I can't be more specific

 

[DPG]

One of those things where if it was in my house I would probably do it!

 

[telectrix]

One of those things where if it was in my house I would probably do it!

so would I. the signal voltage is that low it's relatively close to 0V, which is what the cpc (as a cpc) is at. it's not insulated then. obviously if a new cable could be run without major disruption/redecoration, the that's the way to do it. as long as there's a note at the CU explaining, can't see a problem from a practical point. ( then again, my middle name is Bodge-it. .)

 

[leep82]

so would I. the signal voltage is that low it's relatively close to 0V, which is what the cpc (as a cpc) is at. it's not insulated then. obviously if a new cable could be run without major disruption/redecoration, the that's the way to do it. as long as there's a note at the CU explaining, can't see a problem from a practical point. ( then again, my middle name is Bodge-it. .)

Unfortunately s new cable cant be run in. Im not to impressed with this lightwave stuff. I mean it looks inpressive when your turning things on/off via your phone but ive found their customer service awful. I was going to add that i could place a label at the DB stating what had been done.

 

[westward10]

The magnitude of voltage it carries is not relevant, the conductor is no longer a protective conductor and hence requires insulation.

 

[westward10]

By using the cpc as a signal conductor it has effectively become a Band I circuit and Regulation 528.1 applies.

 

[Pete999]

By using the cpc as a signal conductor it has effectively become a Band I circuit and Regulation 528.1 applies.

BBB or BYB?

 

[westward10]

BBB or BYB?

Whatever colour you want Pete back to Reg 525-8 of the 15th Ed

 

[Lucien Nunes]

I do not think the lightwave Gen.1 control terminals are electrically separate from the mains circuit. It may only use low voltages for signalling, but unless it is electrically separate, it must be considered a live conductor for safety purposes, therefore the bare core of T+E is unsuitable in practical terms, quite apart from whether it technically complies which it wouldn't anyway. It is uninsulated (only mechanically sheathed) and therefore non-compliant for any voltage.

Lightwave Gen.2 might solve your problem - only one unit handles mains (run the SL or the PL down one of the strappers to bring them together at one unit) and the others control it wirelessly.

 

[Pete999]

Whatever colour you want Pete back to Reg 525-8 of the 15th Ed

Amazed

 

[westward10]

Amazed

Why's that?

 

[Deleted account]

Unfortunately s new cable cant be run in. Im not to impressed with this lightwave stuff. I mean it looks inpressive when your turning things on/off via your phone but ive found their customer service awful. I was going to add that i could place a label at the DB stating what had been done.

Why can't a new cable be run?

 

[littlespark]

Gen1 LightwaveRF?
Just use one main switch, only needs live and switchwire. The other switches could be battery powered slave switches paired with master switch.
All your extra cables could be made safe and left in the back of the boxes.

 

[Deuce]

As it's just an ELV signal, can't a length of lightweight signal cable be fed between the two somehow? even if it's a slightly obscure route.

Or just tell the customer it can't be done without re-decorating the room

 

[Deleted member 111934]

Follow the manufacturers instructions.
From whats been posted... Personally I wouldn’t do it.
Apart from the obvious with no cpc in the cable there is potential to damage the devices if a fault occurs (230v down the signal conductor).
Also what about possibility of stray voltage on the signal conductor having an adverse effect on operation.

I believe there is a product that will dim from multiple points by Zano by using 2 cores at each point.

 

[Toneyz]

As littlespark posted I think that Lightwave do a wireless switch (slave)

 

[professional]

Even if you insulate the cpc at both ends, a conductor must be suitably insulated along it's entire length. The sheath of t&e is not insulation, it is mechanical protection.