Electrical Wiring questions

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#1544273 29-Apr-2016 21:52

Willuknight:

So based on previous experience, I need 2.5mm TPS 2C+E for the powerpoints, I've been told I only need 1.5mm for the new light. Can I use the same 1.5mm for the additional switch?

When I ran a cable for my light I think the sparkie said the 1.5mm2 required maximum 5A breaker, so you cant put it on a 10A circuit even though the light doesn't draw much current. Its about the cable being able to handle enough current under a fault to trip the breaker safely. For this reason its probably easier to get 2.5mm2 all around.

Time to find a new industry!

gregmcc

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#1544288 29-Apr-2016 22:17

webwat:

Willuknight:

So based on previous experience, I need 2.5mm TPS 2C+E for the powerpoints, I've been told I only need 1.5mm for the new light. Can I use the same 1.5mm for the additional switch?

When I ran a cable for my light I think the sparkie said the 1.5mm2 required maximum 5A breaker, so you cant put it on a 10A circuit even though the light doesn't draw much current. Its about the cable being able to handle enough current under a fault to trip the breaker safely. For this reason its probably easier to get 2.5mm2 all around.

sounds like a plan, ever tried to terminate multiple 2.5mm cables in to a light switch? it's just not going to happen.

Do your self a favour, 2.5mm for power points only, 1.5 or 1.0 for light switches.

regs also state that the cables cannot be upsized, so if the circuit starts out as a 1.5mm you can't put a bit of 2.5mm on the end although you can down size.

sir1963

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#1544371 30-Apr-2016 08:09

webwat:

Willuknight:

So based on previous experience, I need 2.5mm TPS 2C+E for the powerpoints, I've been told I only need 1.5mm for the new light. Can I use the same 1.5mm for the additional switch?

When I ran a cable for my light I think the sparkie said the 1.5mm2 required maximum 5A breaker, so you cant put it on a 10A circuit even though the light doesn't draw much current. Its about the cable being able to handle enough current under a fault to trip the breaker safely. For this reason its probably easier to get 2.5mm2 all around.

see, this is what is dangerous, unqualified people giving advice to people who don't understand.

You are completely WRONG. All you are going to do is create problems.

And yes I am a registered electrician, and no i don't give out advice, I have seen too many cases go wrong.

sir1963

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#1544372 30-Apr-2016 08:11

gregmcc:

webwat:

Willuknight:

So based on previous experience, I need 2.5mm TPS 2C+E for the powerpoints, I've been told I only need 1.5mm for the new light. Can I use the same 1.5mm for the additional switch?

When I ran a cable for my light I think the sparkie said the 1.5mm2 required maximum 5A breaker, so you cant put it on a 10A circuit even though the light doesn't draw much current. Its about the cable being able to handle enough current under a fault to trip the breaker safely. For this reason its probably easier to get 2.5mm2 all around.

sounds like a plan, ever tried to terminate multiple 2.5mm cables in to a light switch? it's just not going to happen.

Do your self a favour, 2.5mm for power points only, 1.5 or 1.0 for light switches.

regs also state that the cables cannot be upsized, so if the circuit starts out as a 1.5mm you can't put a bit of 2.5mm on the end although you can down size.

No you can NOT just downsize. There is more to this.

k14

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#1544377 30-Apr-2016 08:26

Ask the wholesaler if they will let you return a partial roll? My local lets me do that and just charges me for what is used. It is easy to see how much is used with the meter markings on the roll.

Willuknight

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#1544577 30-Apr-2016 19:01

It's $138 for a 100m roll from trademe or $3m from bunnings or ideal electrical.

gregmcc

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#1544607 30-Apr-2016 19:53

Willuknight: It's $138 for a 100m roll from trademe or $3m from bunnings or ideal electrical.

Stay away from the TM stuff, you'll end up with problems.

Can the TM seller provide the SDOC for the cable? Remember the SDOC is a legal requirement this states that it meets the NZ standards

There have been big recalls in Aust. on faulty cable.

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k1w1k1d

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#1544615 30-Apr-2016 20:20

Have you discussed your plans with the sparky?

He/she may not be willing to certify wiring hidden inside walls, installed by you, that can't be seen. How can he/she be certain that you haven't hidden a joint out of site?

richms

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#1544619 30-Apr-2016 20:37

gregmcc:

Stay away from the TM stuff, you'll end up with problems.

Can the TM seller provide the SDOC for the cable? Remember the SDOC is a legal requirement this states that it meets the NZ standards

Asking for a SDOC on there is like asking a lawnmowing guy for a GST invoice

Richard rich.ms

sir1963

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#1544622 30-Apr-2016 20:41

k1w1k1d:

Have you discussed your plans with the sparky?

He/she may not be willing to certify wiring hidden inside walls, installed by you, that can't be seen. How can he/she be certain that you haven't hidden a joint out of site?

The sparky can NOT legally certify the work done by a home owner. It must be done by an electrical inspector.

Also, work done by the home owner may invalidate the insurances.

Willuknight

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#1544624 30-Apr-2016 20:42

Thanks for the concern Kiwi, welcome to the conversation. As I've said, sparky is all good, wiring is going under house, not through walls, so very easy for him to visually inspect if needed and he's confident with my previous work.

sparkz25

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#1546324 3-May-2016 21:26

gen calc would solve a few of these queries as to cable lengths and so on, 2.5mm for lighting is overkill the only time you would use 2.5mm for lighting is in industrial situations and or long cable runs, but you would still fuse it at 6-10a, domestic housing is usually 1mm and thats fine providing that is protected by the sutibale mcb pending on the psc and earth loop, 1.5 would be ample, but it all depends on the cable run length and so on, best to get a sparky to look and tell you what would be suitable for the installation, also have a google for the regs and the act and that will tell you what you can and cant do in your own home

woollettg

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#1548875 9-May-2016 19:59

The other thing to bear in mind is that non certified wiring may void your insurance cover

dirtydutchman

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#1548922 9-May-2016 21:47

sir1963:

k1w1k1d:

Have you discussed your plans with the sparky?

He/she may not be willing to certify wiring hidden inside walls, installed by you, that can't be seen. How can he/she be certain that you haven't hidden a joint out of site?

The sparky can NOT legally certify the work done by a home owner. It must be done by an electrical inspector.

Also, work done by the home owner may invalidate the insurances.

Yes for the record it says that an Electrical Inspector must connect and test work done by a homeowner, but this is only if the home owner has terminated all fittings etc and the only thing left to do is to terminate into switchboard.

If the home owner runs the cabling and lets a registered electrician terminate all sockets and light switches I would happily sign the work off and call it my own.

MY ONLY STIPULATION, I need to be able to see where all the cabling is run to ensure it is installed correctly.

Otherwise the above is no different to an apprentice running my cables for me and I sure as hell am not going to get an inspector to inspect for a couple of new sockets.

I can already see the days that no electrician can self certify any more and everything needs to be checked over by an independent inspector (inspectors are not all knowing btw and I have been failed by one inspector on work that another inspector was happy to liven purely as to how each inspector interpreted the said regulation that covered whatever I was working on at the time)

In short run your 2.5mm 2C +E to your sockets and leave the cable at the switchboard

run your 1.0mm or 1.5mm 2C +E for your light switches (or if you are running cable from one light switch to a new light switch position that is to be a 2 way use 3core)

again leave everything disconnected and let your electrician terminate and certify ( if he is not happy he can simply not connect or certify - once he certifies he is effectively saying he did the entire job and it will void all responsibility on the home owner.

As for getting cable - ask Ideal to put on sundries account and take back what not used, and ask them for a price before you take cable, most wholesalers will still give cable at half decent rates to general joe public, all they care about is the sale

mdooher

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#1548928 9-May-2016 22:05

gregmcc:
sir1963:

Either very brave or very foolish sparkies.

Because you are doing it yourself, it legally requires you to have it signed off by an Electrical inspector,

and electrician can NOT do that.

if the electrician wants to take responsibility they can sign it off, otherwise an inspector needs to sign off before it is livened

Um no... If the homeowner does the wiring and it was not done under supervision, (in this case it was not) it must be inspected by an inspector. The sparkle cannot just "take the responsibility for it"

Matthew

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