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?
