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#145393 - 05/06/06 05:53 AM Red Alarm Wiring
kiwi Offline
Member
Registered: 12/04/04
Posts: 354
Loc: christchurch new zealand
Today I found a house with lots of lighting circuits wired in red twin fire cable. This was original wiring installed as built.

Is this allowed ? I thought red sheathed twin cable was only for fire alarm wiring.

Is (was) it allowed in a domestic building ?

Is there a requirement that makes it mandatory that the house be re-wired ?
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#145394 - 05/06/06 04:23 PM Re: Red Alarm Wiring
RODALCO Offline
Member
Registered: 12/08/05
Posts: 854
Loc: Titirangi, Akld, New Zealand
I think that it is illigal to wire a house in red alarm type wiring.

Also I'm not sure if it is rated for 230 Volts AC.

As far as I'm aware it's only 0.75 or 1 mm² and NO EARTH !

Sent your question to th EWRB, see if John Sickels has the answer.

Cheers

Ray
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#145395 - 05/06/06 05:31 PM Re: Red Alarm Wiring
Trumpy Offline


Member
Registered: 07/05/02
Posts: 8211
Loc: SI,New Zealand
Kiwi,
As far as I'm aware, the red-sheathed 2-Core TPS cable has the same properties as it's white-sheathed brother, ie: has a 600V/1kV rating, the only difference being that it has a Red outer sheath to denote the system as a Fire Alarm system.
Even so, it has a conductor size of either 1.0mm2 solid or 1.5mm2 stranded.
As Ray rightfully mentions, it is contrary to the Regulations to install a cable in Domestic Installations without an integral Earth conductor.
Having said that, I've worked in heaps of houses where the switch wire from the batten-holder to the light switch (in a 3-plated system) is only a 2-Core (Red/Black) cable.
Also depends on when the place was wired originally.
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#145396 - 05/09/06 01:56 AM Re: Red Alarm Wiring
kiwi Offline
Member
Registered: 12/04/04
Posts: 354
Loc: christchurch new zealand
Surely it must have been allowed to wire lighting circuits in the past with no integral earth. I've seen it a million times. Or was it a popular cost-cutting measure that went unnoticed by the inspector ?

Some people may have thought that wiring a domestic dwelling in red twin was okay as there was no fire alarm wiring anyway.
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#145397 - 05/09/06 03:09 AM Re: Red Alarm Wiring
pauluk Offline
Member
Registered: 08/11/01
Posts: 7520
Loc: Norfolk, England
In the U.K., the IEE Regs. only required earths from 1966 onward. Prior to that, earths could be omitted on lighting circuits so long as certain conditions were met: No switches with exposed metalwork, any metal light fixtures to be mounted out of reach, etc.

We had a brief discussion about this here (toward the bottom of page 1 and the top of page 2):
http://electrical-contractor.net/ubb/Forum9/HTML/000772.html
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#145398 - 05/09/06 03:11 AM Re: Red Alarm Wiring
briselec Offline
Member
Registered: 12/28/05
Posts: 141
Loc: Brisbane, Australia
Quote:
contrary to the Regulations to install a cable in Domestic Installations without an integral Earth conductor


If you're referring to AS/NZS 3000, there's nothing against wiring the circuits in twin with a separately run earth wire to each point.

I can't think of any rule that disallows using a cable with a red sheath in a domestic installation that doesn't have a fire alarm panel.
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#145399 - 05/10/06 01:33 AM Re: Red Alarm Wiring
kiwi Offline
Member
Registered: 12/04/04
Posts: 354
Loc: christchurch new zealand
That may be right Pauluk, as most of the twin lighting wire I'm finding now is from houses built in the 60's.

Has anyones regs ever stated that a metal light fitting doesn't have to be earthed if it is placed higher than a certain measurement above ground level ? I've heard that theory alot here and I've never been able to find anything in AS/NZS 3000. ( I can't be bothered looking in the old regs ).
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#145400 - 05/10/06 02:55 AM Re: Red Alarm Wiring
briselec Offline
Member
Registered: 12/28/05
Posts: 141
Loc: Brisbane, Australia
Quote:
Has anyones regs ever stated that a metal light fitting doesn't have to be earthed if it is placed higher than a certain measurement above ground level ?


when it's not in an earthed situation which means more than 2.5 metres above the ground or any exposed conductive part.
Check the definition for earthed situation and Clause 5.4
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#145401 - 05/11/06 12:38 AM Re: Red Alarm Wiring
Trumpy Offline


Member
Registered: 07/05/02
Posts: 8211
Loc: SI,New Zealand
Quote:
If you're referring to AS/NZS 3000, there's nothing against wiring the circuits in twin with a separately run earth wire to each point.

No I'm not actually, before the AS/NZS thing and still, we have our own Regulations here, have you read them?.
The fact that local Regulations are being watered down in favour of a "one size fits all"
across countries, is just one of the reasons I'm happy with leaving this industry.
AS/NZS 3000 is nothing more than a compromise, from both sides.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin
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#145402 - 05/11/06 01:47 AM Re: Red Alarm Wiring
briselec Offline
Member
Registered: 12/28/05
Posts: 141
Loc: Brisbane, Australia
Each state has it's own electrical regulations. AS/NZS 3000 is simply a document and requires local legislation to make it enforceable.
Why do you consider the wiring rules a compromise? What don't you like about it?
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