1. Insider’s Guide to Faster Safety & EMC Testing
Intertek Testing Services
70 Codman Hill Road, Boxborough, MA
www.intertek-etlsemko.com
2. Introduction
Bringing a new product to market is a complex and involved process that
requires the talent and expertise of a wide range of personnel within an
organization; business strategists, product designers and engineers, production
teams and line staff to name a few. Amidst the flurry of development activity
within these teams, Safety and EMC product compliance issues may seem to be
a low priority – at very least until a prototype is built. Indeed how can you test
something for compliance when it doesn’t actually exist?
By postponing compliance considerations until later in
the development cycle, it can cause delays in launching
a product to market. Testing can reveal non-
conformities that require a product redesign or
modification then retest – lengthening the compliance
process significantly. Indeed it is common that
modifications made to a product for EMC compliance
can effect safety compliance. For example, having to
add extra insulation into a product can reduce the
current creepage and clearance distances required for
safety purposes, potentially making it unsafe. Similarly,
changing bypass capacitors to comply with safety
leakage current requirements can throw off EMC
compliance. The product then has to be modified to fix
this problem and then retested for safety.
With such a potentially complex situation, it seems obvious that product safety
and EMC compliance should be considered from the earliest concept stages of
development (and in an integrated way) to keep launch disruption to a minimum.
Product modification and retest delays can have a critical impact on your
business, potentially costing you thousands in lost revenue (missing out on
Holiday sales for example) as well as damage to your brand. Your competitors
could get their rival products to market first, making them - in a consumers mind
at least - a “leader” and everyone else that comes after a “follower”.
In this document, we will explore some simple, practical strategies that ensure
these compliance considerations can be addressed early, and enable the
compliance process itself to be optimized to help reduce time to market, costs,
chances of delay and the likelihood of having to make frustrating modifications
and retests to your product.
3. Knowledge is Power
It is a cliché to say knowledge is power, yet despite that, it is true.
When a company decides to expand its portfolio of products, the first thing done
is market research. Is the product needed/wanted in the marketplace? What are
the competitive products, and what are their weaknesses? What features would
make the new product better than anything else available? What would its life
be? Would it need to be repairable/upgradeable? Does it have to be functional or
aesthetic or both? How much should it cost? And most importantly, to whom is
this product targeted and in which countries can it be sold?
These last two items of information are essential
knowledge for the development team, so try and
get a copy of the market research for the
proposed product. Depending on the depth of
the research, this will give some indication as to
any special Safety or EMC conditions that may
have to be considered during the design (e.g. Is
this product for home or commercial use; is it
aimed at able-bodied users? Or children or the
elderly?) and it will also show which regional
regulations will have to be met.
This knowledge is key to organizing the compliance schedule and budget itself
as you can use the existing knowledge of your engineers to identify the probable
Safety and EMC test plan and likely costs – based on previous projects. For
example, in the US, domestic products must be tested for EMC emissions, not
immunity. In Europe, domestic products must be tested for both. If your product
is going to Europe, your test plan for compliance in this region is therefore likely
to take a little longer, cost a little more and will probably require more samples
and spares to be provided to the test house. These factors can then be built into
your compliance plans, helping you to anticipate the requests of the test house,
saving you time when you actually come to the testing stage.
4. Standards & Local Deviations
Knowing the safety and EMC regulations for a new
product in the target market is essential for the
product development team. This enables them to
obtain appropriate Standards for those markets
(indeed they can select Standards that give them
maximum geographical coverage) and design the
product with the safety and EMC requirements of
these Standards in mind.
Standards & Jurisdiction
US - FCC/ FDA
US/EU - FCC, IEC, CENELEC
Asia Pacific - FCC or IEC with deviations
Product Jurisdiction Standard
ITE USA FCC Part 15, 60950-1
ITE EU, Asia CISPR 22/EN 55022, CISPR 24/EN
55024
Medical USA, International IEC 60601-1-2
Test/Measurement 61010-1
Audio/Visual 60065
Household Appliances 60335-1
Electrical Tools 60745-1
ISM USA FCC Part 18
ISM EU, Asia EN 55011 +…
Lab USA Exempt
Lab EU EN61326-x
Radio USA FCC Part 15, 22, 24, 25, 27, 74, 90, 95
Radio EU ETSI EN, EN 301 489 -x
5. Insider’s Guide to Faster
Safety & EMC Testing
Purposefully designing a product for safety and EMC conformity seems a
cautious and conservative approach to product design that restricts creativity and
innovation, but it is likely to reduce your chances of product failure at the testing
stage.
A Note on Standards Use
Many companies maintain an
in-house library of Standards
that relate to their product
ranges with a view to ongoing
safety and EMC compliance
within their target markets.
These libraries can be
extremely effective in aiding
designers, but two issues need
to be highlighted. The first is
the matter of interpretation.
Some of the language used in
Standards – particularly in
those sections relating to specific tests to be conducted, can be interpreted in a
number of ways. Calling upon the expertise of a testing and certification partner
to interpret the fine detail of a Standard can help designers and engineers
overcome the hazards of ambiguity and potential product non-conformity. If the
issue has particular subtleties, your test partner can even approach the
Standards Developing Organisation (SDO) directly for a definitive explanation.
The second issue with in-house Standards libraries, is the need to maintain the
latest version of the Standard. When potentially dozens of Standards need to be
maintained, it is possible that an expiring document may be overlooked. Here
auditors and quality managers play their part in keeping the available documents
up to date – but again your testing and certification body can provide you with the
latest (and upcoming) Standards updates and information on local safety and or
EMC deviations that might apply to a sub-section of your target market.
Standards are expensive! But on the other hand, how expensive is it to re-work a
non-compliant product design, or, how expensive is it to miss a product launch
date in the market place? Purchase of the standard is a good investment and is
quite inexpensive when compared to the cost of re-submittal to the test lab.
6. Insider’s Guide to Faster
Safety & EMC Testing
Understanding Dates of Withdrawal (DOW) and Standard Version
terminology
Ensuring that you’re using the appropriate standard is an obvious thing, but
understanding the validity of dates within those standards is critical to using the
right one! It would be incredibly frustrating to commission product tests against a
Standard in your library and then find that it is soon to expire and that any testing
and certification will need to be revisited.
The new version of the Standard my not require any additional tests to be
completed – it could be a something as simple as a new labelling requirement,
but it could require product modifications and a re-test. Understanding how the
dating information in Standards works could save you time and expense in
having to revisit your test program soon after completion because the Standard
that was tested against is no longer the newest version.
Outlined below are some brief explanations of critical Standard dates and
terminology for standards in the EU:
Approved Draft
The Approved Draft Date is usually found in the Foreword at
the front of the Standard. This date is essentially when the
Standard text was “Approved” by CENELEC, prior to
publication by the National Standards Bodies.
DOP - Date of Publication
The DOP or Date of Publication is the date by which the Standard must be
published by all countries’ National Standards Bodies. The DOP is usually 6-12
months after the document has been “Approved” by (for example) CENELEC and
once the document is published, it becomes the current version of the Standard.
Amendment Dates
As you would expect, Amendments to Standards (also found in the foreword and
designated with the letter A and numbered in sequence e.g. A1, A2 etc) also
have an Approved Draft Date and a DOP, but in European Standards, you will
also find a Date of Withdrawal (DOW). This DOW indicates the date when the
Standard it is associated with can no longer be used on its own - i.e. without the
new Amendment. DOWs are also found on fully re-issued Standards. It doesn’t
indicate that the Standard as a whole will cease to be current on that date.
7. Insider’s Guide to Faster
Safety & EMC Testing
Amendment Numbers
An interesting point to note is that
Amendments are numbered in a specific
way. Generally speaking a single number
after an A, e.g. A1, A2, A3 etc indicates
that an amendment applies to both IEC
and EN versions of the Standards.
However, if an amendment only applies to
the European Standards - say in order to
comply with a piece of European
legislation then a two digit number will be
used, e.g. A11, A12, A13 etc. Essentially if
you have an A1 amendment and an A11 amendment in the same document -
you haven’t missed amendments 2,3,4,5,6,7,8,9 & 10! - It’s just that there are two
different amendments to that Standard; one for International use, one for
European.
BS, EN & IEC
The name of a Standard will be designated with a BS, EN or an IEC. A BS
designation indicates a British Standard, an EN designation indicates that it is a
European Standard and an “IEC” designation indicates a worldwide Standard.
Part 1s and Part 2s
Many Standards will be divided into part 1s and part 2s. Part one usually refers to
a generic category of products - for example “Household and similar electrical
Appliances” and gives details of general requirements for them and part two
refers to specific items in that category, say for example room heaters.
REMEMBER!
For certification purposes, a product can only be said to conform to a Standard
that is still current. For example if I test a product to a particular Standard and
then an amendment is published for it, my product will not comply with the most
current (now amended) version of the Standard once the Date of Withdrawal on
that Amendment is passed.
Similarly, if you have a Certification for a product that doesn’t expire for several
years - but the Standard that was used to get that Certification gets Amended
before your certification runs out, you must contact your Certification Body to
enable them to determine what you need to do to comply with the latest version
8. Insider’s Guide to Faster
Safety & EMC Testing
of the Standard. Sometimes you may need to do additional testing - sometimes
the conformity is purely a documentary exercise but you must ensure that your
product meets the most current version of the Standard.
The Devil is in the Details: Designing for Compliance
Continue to use the knowledge and expertise of your product designers and
engineers to “design for compliance”, but also use the available product
Standards as design reference tools and even look at existing best of breed
products to see how they have overcome certain design challenges.
By establishing safety and EMC compliance as a
fundamental design goal, along with functionality,
ease of use, aesthetics etc at the start of the design
process, compliance issues can be tackled earlier in
the design cycle. Compliance will be seen as a
production imperative not a last minute addition to
the project. This will reduce chances of product
failure at the test phase as the product itself will be
“designed for compliance”.
Issues to consider during the design phase:
• Materials – knowing the characteristics of the materials that could be used
in the product and how they behave in certain environments can help you
choose materials that make optimum contribution to safety and EMC
compliance
• Printed Circuit Boards (PCBs) – Consider the architecture and positioning
of PCBs for optimum protection
• Ventilation – Keeping a product cool is important but will the venting
enable EM radiation to seep out at unacceptable levels? Or bring
instability to the system?
• Shielding – by adding shielding to prevent EMC emissions, are you
reducing the clearance of electrical components within the system? Will
the extra material enable the system to overheat?
• Family resemblance – Perhaps minimize the differences within suites of
products if you want to minimize the testing they have to undergo. The
9. Insider’s Guide to Faster
Safety & EMC Testing
fewer the differences between them the less complicated (and costly) the
testing will be.
• Cabling – does the cabling have optimum shielding and protection?
• Software and virtual testing – some immunity upsets can be corrected or
mitigated by suitable operating software/firmware design. Also, consider
the use of virtual testing software. A number of IT packages are available
that can model and analyse a product design that can help designers
design for compliance.
Choosing Components
Where possible use listed or certified components in critical systems in the
product. e.g., controls, transformers, components in the 120 or 240 primary
circuit, etc (and know their ratings and conditions of use) as these will contribute
to the overall compliance of your product.
Also with some specific products – like UK plugs for example, having certified
sub-systems like pre-approved moulded pin inserts means that some of your
testing has already been done and you could save money on your overall test
program.
The temptation to use non-listed components
because they are cheaper can be a false economy –
they are likely to be unproven, and unless the
manufacturer is reputable or at least already trusted
by you, they could be of questionable quality. In
addition, such non-listed components may require
extensive additional evaluation and testing, including
annual re-testing. Just remember if a batch of
components (and even materials) seems a bargain that is too good to be true, it
probably is.
A Note on Modifying Established Products
If you are redesigning or modifying an existing product, even if you are simply
swapping one component for another from a different supplier, don’t forget to tell
your testing and Certification/Approval partner, so they can determine if any
additional testing is required. Swapping one component for another may have
implications that weren’t anticipated when the substitution was made and if you
don’t notify your partner; it may invalidate your certification. Very often
10. Insider’s Guide to Faster
Safety & EMC Testing
substitutions have no impact on a product at all, and no further testing is needed,
but it is important that documentation is updated with the change for auditing
purposes.
Putting Pen to Paper
Documenting the design and production process is invaluable for the compliance
process. Quality Management tools and Project Management systems provide a
useful structure for capturing information that not only can it help an engineer re-
trace their steps and identify a problem if a product shows a non-conformity
during the testing process, but it will also help them to keep track of components
and schematics for easy reference – particularly if they are creating a suite of
products.
The testing and certification team at your
partner laboratory will require access to
the component and materials lists as well
as circuit diagrams and drawings in order
to be able to test and assess the product.
Surprisingly, a great many testing and
approval projects get delayed, not because
of the modification of product or because a
failure of tests, but because the test lab
hasn’t had all of the paperwork they need
to move a project forward. It seems
bureaucratic, but as test houses and
certifying bodies are regularly audited to
ensure the work they do is to a consistent
and of high standard, they need to have all
of the relevant documentation necessary
to conduct the work. Sometimes the most
simple of required “paperwork” (user
manual, installation instructions, product
markings, etc.) is not provided. If a
manufacturer can have all of the relevant
documentation ready for the test house,
frustrating delays can be avoided.
In your records, it is also beneficial to keep a list of contact names and numbers
and email addresses for the team at the test lab, and some calendar notes to
check in regularly with them to check on the project progress. Some
11. Insider’s Guide to Faster
Safety & EMC Testing
manufacturers don’t do this as they want no part of the compliance process, but
many others have found an active dialogue with the test house and an
understanding of and proactive involvement in the process can help reduce the
time it takes and reduces the number of potential issues that could arise.
Design Review
Many manufacturers have found it beneficial to have a design review conducted
by their test or certification partner. This highlights any design issues early and
can be conducted using the circuit diagrams, component lists, design drawings –
and if it is available, a prototype. Initial discussions with the certification partner
can even begin with an artists rendering or cardboard mock-up. If necessary the
product can then be modified or re-worked before ever reaches the laboratory.
Your partner will not only review the product but they can also be used as a
source of reference for interpreting Standards.
The Compliance Process
Understanding the Safety and EMC and
compliance process and actively
preparing for and participating in it can
help reduce the time it takes to complete
it successfully.
It is tempting to hand a product over to a
test house, and take a “hands off
approach” to compliance. Obviously your
laboratory partner has both the expertise
and the facilities to test a product to
Standard and is fully capable of
managing the process. However knowing
the type of tests your product will
undergo and where possible conducting
some preliminary testing yourself, can help give you some initial feedback on
where your product might fail, enabling you to make appropriate modifications
before a product reaches the formal testing stage.
12. Insider’s Guide to Faster
Safety & EMC Testing
What can a man with a radio do?
The most basic of all EMC tests – that you can conduct yourself without
specialist equipment or test chambers - is the radio test. Switch on your radio
and hold it near your live appliance and see if the reception becomes distorted. If
it does, it’s likely that your product needs better emissions mitigation.
Other basic bench tests can usually be conducted at site with some help from
your test laboratory team. They can give you direction on equipment you will
need, guidance on specific tests and even observe some testing so it can be
included in the formal compliance assessment.
Keep it in the Family
When you are submitting products to the laboratory for testing, group them into a
family of products, and submit as many similar items as is feasible at the same
time. This will help to reduce the cost and time required for the compliance
process for multiple items. If that isn’t possible then try and arrange a worst case
(fully loaded) configuration that can represent the other units in the family.
Partners
Choosing to work collaboratively with
a compliance partner like a test
house or a certification body from the
beginning of the design process can
also bring clarity and speed.
Particularly if a manufacturer’s
design team has a thorough
understanding of the compliance
process and can prepare in advance
for the requests of test house.
As well a providing advice on what
Standards should be referenced
during the design phase and how to
interpret them; they can also conduct
design review and give general
guidance throughout the
development of where issues typically lay. This will help manufacturers to
prepare their product for test and reduce the likelihood of failure.
13. Insider’s Guide to Faster
Safety & EMC Testing
Conclusion
In a global market where the ability to innovate and respond to market needs with
new and vibrant products is the mark of world leading brands, time to market is a
key factor in determining both the success of a particular product and ultimately
the ongoing commercial success of a company. As each trading area in the world
has its own set of specific regulations and requirements for these products,
minimizing the time to meet these is critical to reducing time to market.
To reduce the time it takes to complete the compliance process the manufacturer
can:
• Consider compliance issues from the beginning of the design process.
These need to be an integral part of the creation of a new product, not an
afterthought.
• Use the knowledge and expertise available to them to ensure they are
designing product to the latest versions of the Standard, and that they
have taken into consideration the local deviations that may apply to their
product. A test partner will be able to advise on what Standards to use,
and if required, how to interpret them.
• Improve their understanding of, and increase their involvement in the
compliance process. By anticipating the needs of the test house, response
and delivery times can be improved.
• Design for compliance. Deliberately use appropriate materials, proven
designs and approved components that provide adequate EMC shielding
and reduce hazards from electrical shock.
• Maintain a detailed technical file on the project – so when the test house
makes a documentation request, everything required is quickly available.
• Utilize a design review from their partner test house to ensure that they
are on the right track and that any issues can be spotted and rectified
early in the product development process.
There is no magic solution to prevent all of delays with EMC and Safety testing.
Sometimes products fail and sometimes delays occur for other reasons, but with
these simple, common sense efforts, they can at least be reduced. Designing for
compliance is an unromantic notion, but a common sense one. You can optimize
the testing process with proactive involvement, but a well designed product that
meets all of the criteria required of it, will be the most influential factor in getting
through the compliance process, fast.
