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News Issue 6 January 2015
5
MIKE’S
TECH TIPS
Background
An important issue when testing circuit insulation resistance is to ensure
that the test leads are not open-circuited. In some cases this can result in
the maximum possible value that can be indicated being unintentionally
recorded as the insulation resistance value for the circuit or group of circuits
under test.
If the true value for the circuit/s was below the minimum value permitted
by BS 7671:2008(+A3 2015) this could result in a risk of an electric shock or
even the possibility of a fire hazard. This oversight may remain undetected
which could endanger users of the installation, and moreover, the
surrounding area.
Best Practice
The insulation resistance measured in accordance with the method given
in regulation 612.3.2 is considered fine if the insulation resistance is not less
than the relevant value stated in Table 61 of that regulation.
Checking test lead continuity can be achieved by shorting or connecting
the test probes or clips together and measuring the resistance of the leads,
using the low resistance setting or relevant button on the test measuring
instrument. The resistance measured should be the resistance of the leads
and connections which should be less than 5 ohms.
To check that the test leads are operating satisfactorily, the continuity
checks should be undertaken immediately prior to carrying out insulation
resistance measurements and again after the recording of a series of
insulation resistance measurements.
Part of regulation 612.3.2 identifies that the insulation resistance measured
with the test voltages indicated in Table 61 shall be considered satisfactory
if the main switchboard and each distribution circuit tested separately, with
all its final circuits connected but with current – using equipment
disconnected, has an insulation resistance not less than the relevant value
given in Table 61 of that regulation. ©
Current
List of Products
Manufacturer/Distributor Product
ATG Access
SP400 Bollards
Broughton Controls
Defender 941 Barrier
Broughton Controls
Defender 942 Barrier
Cova Security Gates
Miti Gate 10930
Cova Security Gates
Miti Gate 10940
Cova Security Gates
Full Depth Rising Bollard 11840
Cova Security Gates
Shallow Pit Road Blocker 10506
Frontier Pitts
Terra V Gate
Frontier Pitts
Terra Sliding Cantilevered Gate
Frontier Pitts
Terra Ultimate Barier
Frontier Pitts
Compact Terra Barrier
Frontier Pitts
Terra Blocker
Frontier Pitts
Terra Shallow Blocker
Frontier Pitts
Surface Mount Blocker
60
SECOND
INTERVIEW
Claire Kelly
Executive Administrator
What does your role in the PSSA
involve?
I get involved in anything from the
day to day enquiries to exhibiting at
exhibitions, organising conferences,
attending meetings, taking minutes,
and assisting the Secretary and
Chairman
What’s your vision for PSSA over the
next year/ 3 years/ 5 years?
I would like to see the membership
grow, with all companies having a
certain number of products verified
through our verification scheme,
proving even more than today, the
importance and need for this great
organisation.
What’s the first thing you would do if
you were prime minister?
Well I couldn’t move to London and
live at 10 Downing Street, but if I
could do the job still living in Devon
the first thing I would do is make sure
that every large and small business
along with every home in the UK had
super-fast broadband. I would also
offer free education so that every-
one and anyone could achieve their
dream job more easily.
Who would you most like to meet
and why?
I think it would have to be Winston
Churchill. He was an inspirational
statesman, writer, orator and leader.
I think I could have learnt a lot from
him, but I probably would have given
the cigar smoking a miss!!
Technical Product Assessor
MikeWebb