At the risk of repeating the information in earlier posts
and stating facts well known to many here I will try and
summerise the confused position over harmonic
current limits as I understand them.
IEC555-2 and IEC1000-3-2 are both international
standards and are therefore not directly legally binding
anywhere.
When these standards are adopted by the European
standards body CENELEC they are given a EN number
and are given a foreword which gives a date of
announcement (doa), that is the date CENELEC releases
the text; a date of publication (dop), that is the latest date
by which the member states of the EU must publish native
language versions and adopt them as national standards;
and a date of withdrawal of conflicting national standards (dow)
Publication by CENELEC or of the national standards verions
does not of itself make the standards binding in Europe.
This only happens when the title of the standard itself has
been listed in the Official Journal of the European
Communities (OJ) or they have been called up by some
other standard, the title of which has been published in the
OJ and in addition the dop date has been reached. At this
date equipment not within the scope of a conflicting national
standard must comply if it is to be CE makred for EMC.
IEC555-2 was publised by the IEC in 1986 adopted by
CENELEC as EN60555-2 in 1986 and listed in the OJ
in Feburary 1992 (Ref: OJ C44 19/02/92) The scope of this standard was
household appliances and similar electrical equipment. IEC1000-3-2 was
finally published by IEC in 1995 but had by this time already been adopted
by CENELEC as IEC61000-3-2 with a doa of 15 Sep 1994, a dop of 1 Jul 1995
and a dow of 1 Jan 1997 A grandfather clause allows existing designs designs
within the scope of the earlier standard and conforming to that standard to
continue in production until 1-Jan-2001 The scope of this standard includes
all electrical equipment that connects to the low voltage public power
supply with a rating less than 16 amps per phase with lower power limit
exemptions in some classes. The lower limit on class D equipment was to be
lowered from 75W to 50W four years after coming into force although it is
not clear exactly what this means. The limits in the newer standard are
stricter than the earlier one and this lead to strong protests and it was
commonly believed that it had been agreed to delay the dates of this
standard beforeit was listed in the OJ as was done with IEC1000-3-3. However
for some reason this was not done and the listing in the OJ made in Sep 1995
(Ref OJ C241 16/09/95) refers to the standard as published by CENELEC. Since
the dop had passed the standard became immediately an absolute requirement
if a CE making was to be applied for all equipment that was not within the
scope of EN60555-2 but was now within the scope of EN1000-3-2 since there
were no conflicting standards to withdraw. CE marking is not mandatory for
the EMC directive until 1-Jan-1996 but in places like Germany where the
alterative up to that dateis to comply with the in some ways stricter VDE
standards, this presented an immediate problem for manufacturers. In the
absence of any future changes, equipment within the scope of EN60555-2 may
continue to meet only this standard until it is withdrawn as conflicting
with EN61000-3-2 on 1-Jan-1997. It has been proposed that EN61000-3-2 be
ammended so that the dow is delayed until 1-Jan-1998 allowing EN60555-2 to
continue to apply to equipment within its scope until that date. It was
farther proposed that a clause should be added to allow equipment within the
scope of EN61000-3-2 but not EN60555-2 until 1-Jun-1998 to comply. It is
not proposed to change the date of the lowering of the lower power limit of
class D equipment immediately but this may be changed in the intervening
time.
This proposal is out for a 2 month vote.
I rang around several people today that might be in a
position to know the result of this vote but none did.
Even if the vote is successful, and it is not certain, it
is unlikely to be listed in the OJ until May. This leaves the
crazy situation of having to conform for 6 months or so
and then having 18 months in which you don't need to.
I suspect the UK authorities will turn a blind eye to
to a technical breach of this standard during this time
provided the vote is positive but I not so sure the
German authorities will.
Nick Rouse
