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Posted By: Trumpy Earth-Loop Testing - 09/08/02 05:49 AM
A change to our current Regulations,
over here, have required an Earth Fault
Loop test, be carried out after the
installation of electrical equipment, in
any Domestic,Commercial or Industrial
installation.
This test requires that the Installing
Electrician, after the new work is energised, a test shall be done, that
effectively tests the integrity of the
Phase-Earth and the Phase-Neutral
resistance, as this will find the final
size of the O/C protection and also it will
give the size of the expected Fault Current,
under Fault conditions,
Is there a comparative test in the USA
and England?,it's just that now, we are
required to do these tests.
Personally, I have been doing these tests
since I started my time, as an electrical
Boy.
But, what are your thoughts on increased
use of complex test-equipment, to
fault-find power supply problems,
your input, please.
Posted By: pauluk Re: Earth-Loop Testing - 09/08/02 01:15 PM
Earth-loop impedance tests and calculations of prospective short-circuit current have figured in the U.K. IEE Wiring Regs. for years.

Go here for a brief extract on the subject.

Loop impedance testers which measure over a brief period so as not to trip RCDs are available here from (for the "el cheapo" versions) about £50 upwards.
Posted By: Trumpy Re: Earth-Loop Testing - 09/11/02 07:25 AM
Paul,
I have always maintained the idea,that
New Zealand has always been "behind the
times", as far as Electrical Safety,
is concerned, don't get me wrong, this is
not from the people who install, repair
and service, electrical gear over here,
this comes from the Regulators,
We now have a totally botched system over
here and only the Registered Electricians
of NZ are keeping the system honest.
Over here, Paul,we wait for something to
happen, before we do anything about it,
wether it costs a life or not
Posted By: old Appy Re: Earth-Loop Testing - 09/11/02 08:21 AM
I think it a fine test to have included, but can find no mention of it becoming compulsory. Either in the Regs or AS/NZ3000 (mine turned up today) :-) I can’t understand why not,
I think our apprentices are very well trained (being one of them) and safety and testing are things that are hammered home at every opportunity.

Cheers CW
Posted By: pauluk Re: Earth-Loop Testing - 09/11/02 08:43 PM
That sounds very much like the same principle that most British councils apply to roads. It doesn't matter how much people complain about something being unsafe, it's not until there's a serious accident that anything is done.

As far as making certain tests a requirement under U.K. IEE Wiring Regs. is concerned, the problem there is that as far as residential work is concerned, there is no legal requirement to follow the Regs.
Posted By: Trumpy Re: Earth-Loop Testing - 09/14/02 07:17 AM
With respect to my earlier comments
on Earth-loop testing, there are a whole
heap of tests required for the Certification of an Electrical Installation
these days.
In New Zealand, you are required to do the
following tests:
Before livening:
1)Insulation resistance tests w/ a 500V
Megohm meter
2)Continuity tests w/ a reliable ohm-meter
3)Earth electrode resistance test,
done with a dedicated test instrument and
electrodes.
After livening:
4)Polarity tests, to ensure correct sequence of supply, done at all socket-
outlets, light fittings and fixed-wired
appliances.
5) Voltage test- to ensure that the voltage is within a certain range for the area of
installation.(This must be done with a
voltage meter that is calibrated by the
local supply authority, this is a local thing,as the S/A wants to know of any
voltage anomalies).
6) Phase Sequence- As we all know,a motor
will run backwards if hooked up around the wrong way,but if this 3 phase supply feeds a large transformer for a rectifier system
supplying a large Emergency lighting Plant,
then you have problems.
7)Earth-Loop Resistance- We've all heard
about this!.
8)RCD Tests- All installed RCD's, must be
tested with an approved RCD tester,
using the test button on the RCD(GFCI),is
not considered to be a test.
The RCD must trip in under 300 milli-seconds @ a trip current of 30 milliamperes.
9)Operational tests- These are done on all
fixed-wired appliances,to make sure that
they work properly and safely.
With all these tests required, consumers
do not want to pay for the time needed to actaully do them, but they are the end users of the said safety tests.
What are we supposed to do, put in the
work then run away, quickly?
Posted By: pauluk Re: Earth-Loop Testing - 09/14/02 12:52 PM
All of those you've listed are also "required" by British IEE Regulations, with the exception of #5. (Although naturally a voltage check is made automatically while hooking up the meter for some of the other checks.)

As I've said many times, for residential here it's anything goes. Commercial is another matter, not specifically because of our electrical regulations but because of the "Health & Safety at Work" rules which are enforced by the Health & Safety Executive. Under these rules, many work places now require a full set of annual tests and for records to be kept of the results of earth impedance, insulation values, etc.
Posted By: old Appy Re: Earth-Loop Testing - 09/15/02 08:01 PM
I see Fault-Loop Impedance is still only an optional test.
CW
Posted By: Trumpy Re: Earth-Loop Testing - 09/16/02 06:01 AM
Craig,
Under AS/NZS 3000, the new code,
they have just made Earth-loop impedance
tests mandatory.
Its a shame when non-electrical people
start writing our Regs, it's just like the
whole Downlight thing over again.
[Linked Image]
Posted By: old Appy Re: Earth-Loop Testing - 09/16/02 07:15 AM
Well i will be buggered if i can find where it says it is, got a page number. Down lights oh there is a real can of worm i wonder if they realise just how many are out there.
CW
Posted By: pauluk Re: Earth-Loop Testing - 09/16/02 06:44 PM
So what's the deal on downlights down-under? (Sorry, I couldn't resist that play on words! [Linked Image])
Posted By: Trumpy Re: Earth-Loop Testing - 09/17/02 07:26 AM
Paul,
The low-down on Downlights in this part of the world, is that they are recessed into various types of ceilings over here.
The worst type being the Skillion roof,where you only have, say 200mm, to fit a 150mm fitting into.
Being a fire-fighter, these are not good news, as they are renowned for setting roof-spaces on fire.
The powers that be over here, thought to regulate, the types and sizes of lights, fiited into ceilings.
It is not so much as the fitting of the equipment into the ceiling space, it's when Builders put insulation over the top of them, effectively cutting off their ventilation,hence the temperature rise.
What has actaully compounded this problem,is the advent of Insul-Fluff, this is a mix of wool and macerated paper, spray,this over the top of a few downlights, the result does not take a rocket-scientist, to work out.
But, as Old Appy will back me up on,the Building Industry, over here is so sour
about us having self-certification,that they lump the extra burden of making sure that the safety of our installed light fittings,are not compromised by some Builder, lazily installing insulation over our downlights. :rolleyes
Posted By: old Appy Re: Earth-Loop Testing - 09/17/02 11:22 AM
Yep they be a pain in our collective arses
Posted By: pauluk Re: Earth-Loop Testing - 09/17/02 09:47 PM
Sounds familiar. The house at Bacton pictured in my thread of a couple of months ago had downlighters in the remodeled kitchen/dining area, and somebody there had installed fiberglass insulation right over the whole lot.

Who is responsible for seeing that such a thing doesn't happen here? Good question, but I don't think there's any official answer. Logic tells me that it depends upon which is there first: If I fit downlighters in a ceiling which already has insulation, then it should be up to me to remove the appropriate portions. If the insulation mob come along after I've fitted the lights, then I think it's their responsibility to not cover them up.
Posted By: sparky66wv Re: Earth-Loop Testing - 09/17/02 10:30 PM
In the Greenbrier House we took over, we had a problem with a shower recessed canister (Air tight, IC) that was cycling with the thermal cut-off.

First we discovered that it had an A19 60W bulb instead of an A19 40W, and we thought we'd fixed it.

Nope!

Later in the attic, we discovered that the canister had about 2 feet of blown-in cellulose insulation on it!

Go figure!
Posted By: Trumpy Re: Earth-Loop Testing - 09/18/02 07:48 AM
Just as a sideline, to what I said the other day, about the Building Industry Association,
not liking our self-certification, a really large scandal has broken out over here, because of this particular Association, giving the blessing being given to a large number of high-rise apartments in Auckland and in various other parts of NZ, they are now leaking and have a problem with cantilevered balconies, rotting away.
Note that these are in new houses, not in
places that are a few years old.
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