STANDARDS & REGULATIONS IEC 62368-1
“was getting ‘messy’.”
As a result IEC 62368-1 was
conceived as a replacement for these
existing standards.
“The European version of IEC
62368 has been around for a number
of years, but becomes mandatory in
December,” Poate explained.
It comes at an interesting time
for the UK with Brexit set to happen
but Poate suggested that whatever is
agreed by the UK and Europe, in their
on-going trade talks, it would take
a large team to re-write standards
that have been developed over many
years.
“No matter what deal is agreed, I
think from next year the UK will look
to operate with a harmonised set of
European standards. There’s really no
way we can re-write the thousands of
different standards that are currently
in operation.
“Going forward, however,
I think there may be a push
towards developing particular
UK standards. However, I would
argue that they would have to stay
aligned to European standards, as
manufacturers will not want to work
with additional barriers to trade.”
While the biggest change with IEC
62368-1 is the adoption of a hazard
rather than test-based approach, the
testing requirement for batteries has
also become more onerous.
“The requirements for batteries
are more stringent and the standard
has looked to become more ‘future
proof’, with the aim of keeping up
with developments in the technology.
We are seeing more battery powered
consumer products and a move
away from mains-powered devices to
lithium ion rechargeable batteries –
the standard needed to reflect that.”
A change of mindset
According to Poate IEC 62368-1 will
require a significant change in mindset
among engineers, when it comes
to testing and compliance.
“With this approach an engineer
is not designing a product to meet
a particular set of criteria in order to
pass a specific test,” he explained.
“Rather they will have to identify
possible hazards in their products,
quantify them and then restrict
access to those hazards.
“In the past, engineers would be
confronted with a prescriptive set
of requirements against which their
design would need to be validated – a
list drawn up by those who wrote the
standard. It was very easy to follow,
but how did you as an engineer
know that all the hazards had been
addressed? You were only working
with those already identified, not new
ones.
“IEC 62368-1 has turned that
approach on its head and forced
the design engineer to look at their
product afresh, and requires them
to identify potential hazards. That
sounds easy, but can be quite
challenging, especially for engineers
who are used to working with a set of
prescriptive tests,” suggested Poate.
Accordingly, while the new
standard doesn’t throw away those
types of tests, it does call for the
identification of likely hazards to take
place first and only then for the use of
prescriptive tests to pass or fail that
device.
“IEC 62638-1 is a hazard based
safety engineering methodology which
requires you to identify potential
hazards, whether that concerns
electrical, thermal or mechanical
safety and so on, and mitigate
against them.
“Take a fan that sits inside a
laptop, for example. It has a moving
element - rotating blades - so that
would be identified as a low risk
hazard – but whatever the level of
hazard, the concept is the same.
“Taking this example, you will have
identified the blades as a hazard,
documented that and by doing so
ensured that anyone would be able to
see what was identified as a hazard
and, perhaps, what was overlooked.”
According to Poate, once the
hazards have been identified, then
the various safeguards required
can be selected and the necessary
prescriptive testing carried out.
“You are being asked to
manage the risk associated with
the hazardous part by employing
safeguards. Only then do you fall
back on the prescriptive testing that
was at the heart of the previous
standards, so you can test the
integrity of those safeguards that
have been selected.
“This is the heart of the new
standard. You are identifying the risks
first, then applying the safeguards
and testing them.”
The biggest benefit from this
new approach is that the engineer
does not have to design to a specific
standard, so there’s more flexibility as
a result.
“To start with it will be a bit more
restrictive – we are replacing a
tried and trusted methodology with
something very different. Engineers
will not have used this approach
before but, in time, I believe that
once they get use to the new
methodology it will give them much
more freedom with their designs,”
argued Poate.
The prescriptive test-based
approach of the old standards left
little room for subjectivity, as they
required engineers to apply specific
tests to prove compliance.
By contrast, IEC 62368-1 takes
a more subjective approach which
relies on engineering expertise to
identify potential hazards.
“It’s not prescriptive and will allow
designers to think outside the box,
with the potential for radically new
designs that could use new materials
or be lighter, more cost effective, or
come with better features.”
However, not every individual
engineer may identify exactly the
same hazards when considering a
similar product.
“Only time will tell if this new,
more flexible, less objective approach
will ensure that products remain
safe,” concluded Poate.
“Only time will
tell if this new,
more flexible,
less objective
approach will
ensure that
products remain
safe,”
Richard Poate
www.newelectronics.co.uk 13 October 2020 19
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