Hi Alex,
The EMC standards governing vehicle electrical sub-assemblies (ESAs)
are as follows:
1 - Radiated emissions - 95/54/EC (automotive directive) and CISPR 25
2 - Conducted emissions - CISPR 25 ( omitted by directive )
3 - ESD is governed by ISO 10605. The test levels are 15kV air discharge for
ESAs
that can only be accessed from inside the vehicle and 25kV for ESAs that
can be
accessed from outside the vehicle (e.g. through open window). Contact
discharge is 8kV
for points accessible during normal operation.
4 - Fast transients and Bursts are replaced by ISO 7637/SAE J1113/11 in the
form of test
pulse 3a and Test pulse 3b
5 - Surge immunity is replaced by the automotive load dump, ISO 7637 Test pulse
5. This
is the most destructive of the transients.
6 - Transient immunity is completed by the other test pulses in ISO 7637 (test
pulse 1,2, 6)
Test pulse 4 simulates the supply transient during cranking. You may want
to look
closely at the behaviour of your machines during this phase as access to
memory can
often result in corruption of data. Additional requirements may exist like
twice the supply
voltage for a jump start on a 12V battery.
Note that the transient test levels specified for 12V and 24V vehicles are
different and
governed by ISO 7637-1 and ISO 7637-2 respectively.
7 - Radiated immunity - ISO 11452. Minimum test level is 25V/m (SAR) to meet
requirements
of the directive, but most vehicle manufacturers might ask for higher test
levels like
50V/m and even 100 - 200V/m for safety critical ESAs. Frequency range is
nominally
150kHz - 1GHz but it is common practice and vehicle manufacturers do tend
to insist on
tests starting at 10kHz.
The Bulk current Injection test is also useful verification that you have
left no stone unturned.
It is described in detail in ISO 11452 Part 4
Depending on where your terminals will be fitted, the operating temperature
range may
change from the commercial, especially the lower limit which may have to shift
from
0 to -40?C but I imagine you have accounted for this already and besides,
financial
transactions may be rather low on the list of priorities for a driver entering
a cab at -40,
but I haven't been to Russia on a cold day so ignore me. Of course I jest.
For general safety, you will have to refer to the SAE standards. I cannot say
for sure if
EN60950 is adequate.
http://www.sae.org/technicalcommittees/index.htm
Hope this helps
Regards
- Chris Chileshe
- Principal Electronics Design Engineer
- Ultronics Ltd
- http://www.senstronics.com
-----Original Message-----
From: Alex McNeil [SMTP:[email protected]]
Sent: Tuesday, February 26, 2002 11:35 AM
To: '[email protected]'
Subject: Vehicle EMC and Safety standards
Hi Group,
Our financial transaction terminals are mostly used in the commercial area
e.g. shops and offices, which use a separate AC/DC power supply block
connected to the mains There is a requirement for these same products to be
used in vehicles e.g. Taxis and Buses. These would use the power from the
batteries possibly from the cigarette lighter holder (12Volts). I have
obviously had to design in additional filter circuitry to account for this
type of DC Supply source.
My question is, will there be additional EMC and Safety requirements in
Europe or North America (other than those already approved for use in
commercial areas) for vehicle/mobile use?
Already Approved to:
EMC: EN55022 Class B, *EN55024, EN6100-3-2, EN61000-3-3, FCC Part 15,
ICES-003
Safety: EN60950 (also UL/CSA)
*The only additional test I can think of is for the EN55024 to include the
DC Power Port tests (excluded before due to the terminal being supplied from
an AC/DC power source).
As usual I look forward to your invaluable replies.
Kind Regards
Alex McNeil
Principal Engineer
Tel: +44 (0)131 479 8375
Fax: +44 (0)131 479 8321
email: [email protected]
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