Question for sparkies: Heated towel rail, lighting circuit

[p.dath]

One of my next projects involved putting in a heated towel rail into the bathroom.

My problem is the only wiring remotely close is a lighting circuit. It is current not protected by an RCD. Laying in a feed from a power point is going to be a major.


The heated towel rail uses a maximum of 60W. It I change the fuse for the lighting circuit to an RCD, can I feed a heated towel rail from a lighting circuit?

When I have questions, I usually refer to the guide "New Zealand Electrical Code of Practice for Homeowner/Occupier’s Electrical Wiring Work in Domestic Installations", but I can't find the answer I'm looking for.
http://www.med.govt.nz/energysafety/...202004%20.pdf/

ps. The electrical connection will be in "Zone 3".

[neels]

From reading the link supplied - In zone 3 you're fine as long as the lighting circuit has an earth, no IP rating or RCD required for switches or appliances in Zone 3, a PCU is not a socket outlet.

6.7 ELECTRICAL APPLIANCES (HEATERS, HEATED TOWEL RAILS, FANS ETC)6.7.1 The following must apply to the installation of electrical appliances in the classified Zones:
(a) Zone 0: electrical appliances with the required degree of protection, IPX7; and, specifically designed for Zone 0 and installed to the manufacturerer’s instructions; and, operated from a safety extra-low voltage system not exceeding 12 V AC. or 30 V ripple free DC, with the supply source located outside Zone 0;
(b) Zones 1 and 2: IPX4;
(c) Zone 3: no IP rating required.
NOTES: 1. Instantaneous water heaters installed in Zone 1 would be mounted on the fixed plumbing connection.
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2. Extractor fans installed in Zones 1, 2 or 3 could be mounted in the walls or in or on the ceiling of the different Zones.
3. Electrical appliance heaters that you install in Zones 1, 2 and 3 must be mounted not less than 0.3 m above the floor, or have the element totally enclosed in metal (e.g. a heated towel rail).
4. The control switch for these appliances, if mounted externally, must have the required degree of protection for the Zone.

For convenience sake I've always put a switch with a neon for the towel rail in the plate with the light switch.

[Usarka]

Just run an extension cord bro!

[Akzle]

are you switching the rail?

either way, as long as earthy gets eartheyed there should be no problem. general lighting circuits are not earthyed.

[Padmei]

Sparky here. if in doubt get a sparky! Don't listen to guys that aren't as i overheard a carpet layer confidently telling an old fella how to kill hiself with wiring.

That said just get a doubly insulated heated towel rail - but get a sparky to check it. Most sparkies are more thna happy for the owner to mount them as they're a pITA but wiring them in is a piece of cake.


It's debatable that RCDs work without an earth.

[Padmei]

are you switching the rail?

either way, as long as earthy gets eartheyed there should be no problem. general lighting circuits are not earthyed.

That is absolute crap!

[nzspokes]

Really? Heated towel rail?

Guess you ride a Honda.

[Berries]

Really? Heated towel rail?

I went in to Briscoes today and they don't even sell heated towels down here.

Apparently they don't sell enough shandy in Dunedin to make it worthwhile.

[mossy1200]

Not many towel rails arnt double insulated. If the flex on it is 2 core then it is or the square inside square is on the info label it is double insulated.
Light circuit is fine. You need a point of isolation within 1 metre of the rail( perminent connection unit is easiest) and this must not be within 450mm of the side of tub,basin,shower etc. The rail can be closer but not its point of connection and switch.

Rcd protection still works on double insulated appliances.
It works on a system of balance between phase and neutral. If any power above 30mill amps leaks away and does not return on the neutral the rcd trips. This can be via earth wire or any other path(person works fine). The rcd is designed to do this within a time frame that in MOST cases is none leathal.

[p.dath]

are you switching the rail?


either way, as long as earthy gets eartheyed there should be no problem. general lighting circuits are not earthyed.

Yes, it will be switched.

That is absolute crap!

THr lighting circuit does have the standard 3 core TPS, so an earth is definately available.

Really? Heated towel rail?

Guess you ride a Honda.

We still have 4 children living at home, and want to reduce the amount of washing we are doing.

Not many towel rails arnt double insulated. If the flex on it is 2 core then it is or the square inside square is on the info label it is double insulated.
Light circuit is fine. You need a point of isolation within 1 metre of the rail( perminent connection unit is easiest) and this must not be within 450mm of the side of tub,basin,shower etc. The rail can be closer but not its point of connection and switch.

Rcd protection still works on double insulated appliances.
It works on a system of balance between phase and neutral. If any power above 30mill amps leaks away and does not return on the neutral the rcd trips. This can be via earth wire or any other path(person works fine). The rcd is designed to do this within a time frame that in MOST cases is none leathal.

It does have the square symbol on it, but the flex coming off it is 3 core.

I think I'll get an RCD. If it keeps trippping because of the heated towel rail I can always use it somewhere else.

[Akzle]

That is absolute crap!

huh?

i was wondering about all this two core in the roof.... magic earth eh?

[neels]

I think I'll get an RCD. If it keeps trippping because of the heated towel rail I can always use it somewhere else.

RCD is not a bad idea anyway, pretty cheap insurance if you've got 4 kids in the house, it shouldn't trip unless there is a fault somewhere in which case you'll probably be glad you had it.

huh?

i was wondering about all this two core in the roof.... magic earth eh?

In a lot of cases there is 3 core with earth to the switch, but only 2 core to the light as it's feeding a batten holder which doesn't get earthed.

[AllanB]

I thought all electrical hook-ups of this nature are to be done by a qualified sparky by law. You can pre wire etc but the sparky has to cert it. They are taking the DIY out of many things like this and rest assured if you DIY it and burn the house down the insurance company will want to know who wired the towel rail ........

Then again do you really want some tradie in your house whacking off over over your wifes knickers? Target - what a show eh?

[p.dath]

I thought all electrical hook-ups of this nature are to be done by a qualified sparky by law. You can pre wire etc but the sparky has to cert it. They are taking the DIY out of many things like this and rest assured if you DIY it and burn the house down the insurance company will want to know who wired the towel rail ........

From Electricity Act section 169, clause 20:

110. Exemption for domestic electrical work – (1) Notwithstanding anything in section 108 of this Act, the owner of any premises that are occupied or intended to be occupied by that person as a residence for that person, or for that person and members of his or her family, may do any electrical wiring work, or assist in doing any electrical wiring work, in relation to those premises, if–
(a) That work is within the limits prescribed in regulations made under section 169 of this Act for the purposes of this section; and
(b) The work is carried out in accordance with the requirements of any regulations made under section 169 of this Act; and
(c) The work is carried out in a competent manner; and
(d) While that work is being carried out, no part of the work is connected to a power supply; and
(e) Where required by regulations made under section 169 of this Act,
(i) Before connection to a power supply, the work is tested and certified by a registered electrical inspector in accordance with regulations made under that section; and
(ii) The work is connected to a power supply by such an inspector.

ps. And it needs to be an electrical inspector, not just a sparky.

[Coldrider]

From Electricity Act section 169, clause 20:


ps. And it needs to be an electrical inspector, not just a sparky.

So it would be alot simpler just to get a sparky in the first place.