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Topic Title: RCDs in Australia
Topic Summary: Why arent they getting tested
Created On: 28 April 2018 07:54 AM
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 28 April 2018 07:54 AM
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keithredpath

Posts: 550
Joined: 30 March 2002

I used to live in the UK but now live in Australia. I am fascinated by the fact that RCDs must be tested by manual tripping and by testing at the usual intervals in work places. This is the law in Australia. However there is no requirement to test them in houses. We live in a Shire that has 12,000 Houses, all of which by law must be fitted with RCDs but there is no requirement to test them. The majority of home owners and tenants do not know what an RCD is and because most of the distribution boards are outside their houses they will probably never know. My previous experience tells me that eventually we will have a problem with these RCDS not tripping when required. This is an accident waiting to happen. I am drawing up a Business Plan to combat this situation but I am struggling to get an Electricians Licence.
PS. Can anyone tell me if it is ok to put RCDs on smoke alarm circuits?
and is it ok to mix smoke alarm circuits with lighting circuits?

-------------------------
keithredpath
 28 April 2018 08:12 AM
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dustydazzler

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Since the 17th all new builds and full rewires will near always have all rcd boards fitted. So yes domestic smoke alarms will be rcd protected, whether they share a circuit with the lighting that's up to the installer.

As for not testing rcds once they are installed , I would bet my weeks pocket money that 99%of the general public in the U.K. do not test their household rcd every 12 weeks. Infact probably never
 28 April 2018 08:15 AM
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dustydazzler

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As for not trip testing rcds in Australia,

Just Remember you can make something 'the law' but if no nobody is there to enforce Z law it ain't worth the paper it's written on

At best you could lobby the state government to pass a law so that all consumer units should have a big yellow label stating rcds should be periodically trip tested
 28 April 2018 08:44 AM
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Zoomup

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Yes Keith it would be a very good idea to have regular testing of R.C.D.s. This is especially the case with TT earthing where the device has to be 100 percent reliable. I have come across many R.C.D.s that due to lack of use had seized up and did not operate on test button. If the R.C.D. is in a garage or an outbuilding or external enclosure as many are in Australia then they could be invaded by small insects, dust or be affected by temperature or humidity conditions etc. and not work correctly when required to. We do stick a sticker on R.C.D. enclosures here in the U.K. stating the need for regular testing of the device, but who actually reads these labels and takes any notice of them. I believe that many home in Australia have three phase supplies and 3 phase R.C.D.s. In this case nuisance tripping may be a problem where one fault knocks out everything.

http://www.youtube.com/watch?v=ieIVhHgsF1A

Z.
 28 April 2018 09:04 AM
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dustydazzler

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Forget the bonkers wiring for a second

HOW TALL IS THAT PORCH
 28 April 2018 09:04 AM
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Zoomup

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The three phase R.C.D. in Australia http://www.youtube.com/watch?v=zWsGmrjHtfc

Z.
 28 April 2018 09:25 AM
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dustydazzler

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Wash your hands next time fella if you are going to do a video tutorial

I do like that funky test lamp

Why do they have socket outlets inside the consumer unit ? For periodic testing I presume
 28 April 2018 10:55 AM
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keithredpath

Posts: 550
Joined: 30 March 2002

They don't do Periodic Wiring Inspections in Australia (With a few exceptions). This is why I am out of a job. They tell me I need a full Electricians Licence to carry out my RCD Tests. I need to attend a series of workshops and work under supervision even though I have tested over 250,000 RCDs in the past. They keep putting obstacles in my way. They don't like immigrants over here and are not afraid to say so. There are numerous flaws in their electrical safety culture but they don't want to know. Unfortunately they will wait until someone dies before taking action.

-------------------------
keithredpath
 28 April 2018 11:02 AM
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dustydazzler

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Can't you just test your own rcd for peace of mind

How would they know or find out if you did a bit of occasional home diy testing without the relevant Australian permit
 28 April 2018 02:22 PM
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broadgage

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"This installation , or part of it, is protected by a device that cuts off the power in the event of earth leakage.
Ignore the button marked test.
The day before the 5 yearly safety audit, press the button marked test.
If nothing happens, pretend that it worked and fill in the test card anyway.
Backdate the records to a couple of years before the device was installed"
 28 April 2018 03:14 PM
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keithredpath

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I am compiling a list of circuits where the use of RCDs are contra-indicated. Any ideas?

-------------------------
keithredpath
 28 April 2018 03:23 PM
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Zoomup

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Originally posted by: keithredpath

I am compiling a list of circuits where the use of RCDs are contra-indicated. Any ideas?



Contra-indicated?

Z.
 28 April 2018 04:39 PM
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mikejumper

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Originally posted by: dustydazzler
As for not testing rcds once they are installed , I would bet my weeks pocket money that 99%of the general public in the U.K. do not test their household rcd every 12 weeks. Infact probably never

And how many of us test our RCD's quarterly?
 28 April 2018 05:23 PM
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dustydazzler

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Originally posted by: mikejumper

Originally posted by: dustydazzler

As for not testing rcds once they are installed , I would bet my weeks pocket money that 99%of the general public in the U.K. do not test their household rcd every 12 weeks. Infact probably never


And how many of us test our RCD's quarterly?


Not me
 28 April 2018 05:50 PM
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AJJewsbury

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Joined: 13 August 2003

I am compiling a list of circuits where the use of RCDs are contra-indicated. Any ideas?

Circuits where it's recommended NOT to use RCDs? I can't think of any these days, at least not anything in usual UK domestics. The requirement for 30mA RCD protection for soft sheathed cables concealed in walls tends to mean that all final circuits get 30mA RCD protection. There was a fashion for putting freezers on non-RCD circuits in the early days, but I think most people have got over their FUD on that score now. Some appliances have higher earth leakage (induction hobs for example) but that tends to be solved by using RCBOs to provide individual RCD protection to such circuits rather than omitting RCD protection. Even smoke alarms tend to be on RCD circuits as the cables usually run up a wall somewhere - typically sharing protection with a regularly used lighting circuit to ensure than a trip doesn't go unnoticed for too long (and current detectors have internal back-up batteries anyway).

Generally (other than in TT system of course) there's no need for RCDs for armoured submains (or non-armoured if not concealed in wall) where there's 30mA RCD protection downstream. The only domestic circuit I can think of as a definite no-no for an RCD would be one supplying a surge protection device at the origin - but they're almost unknown in UK domestic still.

Outside domestic - perhaps the supply to a fire alarm panel (if not TT) would be best without an RCD - but the wiring system would have to be appropriate if concealed in a wall (e.g. not just FP). Commercial electronic loads (e.g computer or telecoms racks) probably has enough leakage to make 30mA RCD protection inadvisable. Similarly perhaps outdoor sockets intended for supplying refrigerated transport when parked. Of course other large industrial stuff might not be really compatible with RCDs, but that's outside my experience.

- Andy.
 28 April 2018 06:45 PM
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mikejumper

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Originally posted by: dustydazzler

Originally posted by: mikejumper



Originally posted by: dustydazzler



As for not testing rcds once they are installed , I would bet my weeks pocket money that 99%of the general public in the U.K. do not test their household rcd every 12 weeks. Infact probably never




And how many of us test our RCD's quarterly?




Not me

Have to admit not me either but it does get tested about once a year (intentionally).
 28 April 2018 07:00 PM
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broadgage

Posts: 2929
Joined: 07 August 2007

Originally posted by: keithredpath

I am compiling a list of circuits where the use of RCDs are contra-indicated. Any ideas?


Lighting circuits*
The supply end of submains* (RCD protection preferably at the load end, saves walking when it trips)
Socket outlet circuits for workshops* Instead fit RCD sockets.
Central fire alarm systems*
Central battery emergency lighting systems*
Most types of medical life support equipment*
Fire pumps*.
Smoke extract fans*
Lifts and escalators*
Anything with inherently high leakage currents*

*except when a TT supply make an RCD a requirement, in such cases consider a less sensitive and time delayed RCD.
If soft skinned concealed cables require an RCD, then consider a different cable type.

And almost anything that uses a low enough voltage, SELV or equivalent.
And when an RCD cant be used due to concentric wiring.
Railway traction and similar with an earthed return.
Any circumstances when the risks to national security outweigh electrical risks.
Some types of un-manned sites where risks to human safety can be ignored because there are no humans present. Lighthouses, cellphone repeaters and the like.
Equipment that is INTENDED to give electric shocks, electric fences, electric animal stunning, electric chairs for capital punishment.

Equipment like electric insect killers and neon signs cant be fitted with RCDs in the high voltage secondary circuit, but can of course be supplied from an RCD protected circuit.
 14 May 2018 07:38 PM
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Weirdbeard2

Posts: 526
Joined: 29 November 2017

Originally posted by: keithredpath

My previous experience tells me that eventually we will have a problem with these RCDS not tripping when required. This is an accident waiting to happen.


Hi Keith, we seem to have different experiences with RCDs because I dealt mainly with RCD problems rather than wholesale EICRing and I have never known a single RCD device to fail in performing its intended function, even in the most questionable establishments, which might not have a Main earth conductor, or a lid on the DB thats tripping let alone a comprehensive quarterly or better RCD test button regime. The figures bandied about in the UK of one in 7 RCDs failing to operate are complete tosh. The most popular UK concern nowadays seems to be that RCDs operate more often than is convenient, so it is more popular to have banks of RCBOs rather than split load CUs as they will reduce the inconvenience of the upstairs lights going off at the same time someone plugged into a downstairs outdoor socket is getting a potentially fatal electric shock out in the garden?
 14 May 2018 09:24 PM
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mapj1

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Joined: 22 July 2004

I've had a few fail to trip, but generally when that occurs it has been total loss, not just a bit slow. Last one on my own workshop at home oddly enough. I now have two in series from different makers.

Most recent borderline weird hair tearing RCD issue was one where a colleague discovered that his kit screwdriver with magnetic tips was capable of altering the threshold significantly, presumably by altering the magnetisation of some vital part.

-------------------------
regards Mike
 14 May 2018 09:34 PM
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Weirdbeard2

Posts: 526
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Originally posted by: mapj1

I've had a few fail to trip, but generally when that occurs it has been total loss, not just a bit slow. Last one on my own workshop at home oddly enough. I now have two in series from different makers.


Thanks for the reply, could you expand on how your RCD devices failed to trip?
IET » Wiring and the regulations » RCDs in Australia

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