Treggers, I submitted Grant Pinto's request for information to an expert that I
know of
in the UK with the following response.   I welcome your replies.

Recently Grant  Pinto from Alcatel wrote:

I would appreciate your comments on the following thoughts/philosophy:

The scope of the Low Voltage Directive excludes equipment "with a voltage
rating" (means powered from) -48VDC (or -48 to -60VDC) sources (including
ITE/Telecom equipment.) [Definition from EN60950 - Rated Voltage: The 
primary
power voltage as declared by the manufacturer.]

If the equipment is ITE, it is included in the scope of EN60950.  EN60950 
has
no lower voltage limit and specifically includes equipment intended to be
connected to a telecommunications network.

If the equipment is ITE and not Telecom, the equipment could be tested to
EN60950 as this is a relevant standard.  Of course the equipment must be CE
marked persuant to the EMC directive.  The Declaration of Conformity (DOC)
should refer to the EMC directive, but not the Low Voltage Directive.

If the equipment is ITE/Telecom hybrid, the TTE directive requires (Article
4) that the equipment satisfy requirements for user safety and safety of
employees of public telecom networks operators.  It also requires that the
equipment satisfy requirements for the protection of the public telecom
network from harm.  Whether the LVD applies or not, safety is required.
Therefore equipment should be tested to EN60950 as this is the relevant
standard.  CE marking would be required for the TTE and EMC directives, but
not the LVD as the DOC would show.

In conclusion, 48VDC ITE/telecom equipment should be tested to EN60950, but
CE marking, and the associated DOC, should not include reference to the LVD.


Thanks,

R. Grant Pinto
[email protected]
Certification Engineer
Alcatel Data Networks
703-724-2759
703-724-2132-fax

Tony Leathart, Director of Product Safety, Interference Technology
International, Ltd.
Formerly Director of Product Safety Services at BSI responds thusly:

I agree with all Grant Pinto's points below but he doesn't go far enough. 
 Article 1 of the LVD defines electrical equipment as "equip designed for 
use with a voltage rating of between  .....etc ".  This means that a low 
voltage powered equip with a power supply voltage, eg battery, below the LVD 
range is outside the scope of the LVD EVEN IF it produces high voltage eg 
1000 V ac within the equipment such as a battery powered portable TV.  It is 
the RATED VOLTAGE on the rating plate that is the criterion and this should 
be the voltage of the input power.

Where the equip falls outside the scope of the LVD but in the scope of other 
directives requiring safety eg TTE and Medical Devices Directive then this 
must be covered in the TF by reference to the appropriate harmonised 
standard.  In the case below, this is EN 60950, but there is no DoC covering 
the LVD because it is not relevant.

Equipment that falls outside the scope of the LVD is within the scope of the 
General Product Safety Directive that requires it to be SAFE.  This 
directive is not a New Approach Directive, has no detailed essential 
requirements and does not require CE marking nor DoC nor TF. The enactment 
of this directive in the national law of the various member states is still 
based on existing national rules that apply to such products so the 
presumption of conformity is granted firstly to the national rather than the 
harmonised standard and secondly to Community specifications particularly 
those adopted by national standards bodies.  In this case BS EN 60950 would 
apply to the UK, and incidentally to most if not all member states, because 
it is has been adopted universally. Because the directive has no essential 
requirements against which to test the claim of conformity, it has to be 
standards-based and the designer should design to the appropriate national 
standard of the purchaser's country.

Personally, I would recommend a risk analysis to test whether safety is an 
issue or not.   Often there is no risk with this kind of product because 
there is insufficient energy at high internal voltage to produce enough 
current to cause electrical shock, burn or fire.  If there is no risk, then 
it will not matter whether a formal safety assessment has been made or not, 
but if one is needed then this will show which of the many clauses of the 
standard can be ignored.  Usually, the only risk is the battery exploding if 
it is put in the wrong way round or shorted and this can be prevented with a 
milliamp fuse.   As a precaution, I would also keep the technical 
documentation together in a file in case of an authorised challenge when I 
could show a case of due diligence at the time of first placing the product 
on the market. Naturally, [clients would be better suited to do a comprehensive]
risk analysis, assessment [of conformity with the requirements ] and the
documentation if required [themselves ] and ... cut out most of the standard as
not applicable whereas a test house might do the whole type test and laugh all
the way to the bank.

Regards,
TONY

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