EN 61000-3-2:1995
Limits for Harmonic Current Emissions (equipment input current <=16 A per phase)
Scope
This section deals with the limitation of harmonic currents injected into the public
supply system.
It specifies limits of harmonic components of the input current which may be produced
by equipment tested under specified conditions.
Harmonic components are measured according to annexes A and B of the standard, EN
61000-3-2.
This section is applicable to electrical and electronic equipment having an input
current up to and including 16 A per phase, and intended to be connected to public
low-voltage distribution systems.
The tests according to this standard are type tests. Test conditions for particular
equipment are given in annex C of the standard, EN 61000-3-2.
For systems with nominal voltages less than 220 V (line-to-neutral), the limits have
not yet been considered.
General
The objective of this standard is to set limits for harmonic emissions of equipment
within its scope, so that, with due allowance for the emissions from other equipment,
compliance with the limits ensures that harmonic disturbance levels do not exceed the
compatibility levels defined in IEC 1000-2-2.
Professional equipment that does not comply with the requirements of this
standard may be permitted to be connected to certain types of low voltage
supplies, if the instruction manual contains a requirement to ask the supply
utility for permission to connect. Recommendations concerning this aspect are
contained in IEC/TS 61000-3-4.1)
Classification of Equipment
For the purpose of harmonic current limitation, equipment is classified as
follows:
Class A:
– balanced three-phase equipment;
– household appliances, excluding equipment identified as class D;
– tools, excluding portable tools;
– dimmers for incandescent lamps;
– audio equipment.
Equipment not specified in one of the three other classes shall be considered
as class A equipment.
NOTE 1 Equipment that can be shown to have a significant
effect on the supply system may be reclassified in a future edition of the
standard. Factors to be taken into account include:
– number of pieces of equipment in use;
– duration of use;
– simultaneity of use;
– power consumption;
– harmonic spectrum, including phase.
Class B:
– portable tools;
– arc welding equipment which is not professional equipment.
Class C:
– lighting equipment.
Class D:
Equipment having a specified power according to 6.2.2 less than or equal to
600 W, of the following types:
– personal computers and personal computer monitors;
– television receivers.
NOTE 2 Class D limits are reserved for equipment that, by
virtue of the factors listed in note 1, can be shown to have a pronounced
effect on the public electricity supply system.
The procedure for applying the limits and assessing the results is shown
below.
Limits for Class A equipment
For Class A equipment, the harmonics of the input current shall not exceed the
values given in table 1.
Audio amplifiers shall be tested according to clause C.3. Dimmers for
incandescent lamps shall be tested according to clause C.6.
Limits for Class B equipment
For Class B equipment, the harmonics of the input current shall not exceed the
values given in table 1 multiplied by a factor of 1,5.
Limits for Class C equipment
a) Active input power >25 W
For lighting equipment having an active input power greater than 25 W, the
harmonic currents shall not exceed the relative limits given in table 2.
However, the limits given in table 1 apply to incandescent lighting equipment
that has builtin dimmers or consists of dimmers built in an enclosure.
For discharge lighting equipment that has built-in dimmers or consists of
independent dimmers or dimmers built in an enclosure, the following conditions
apply:
– the harmonic current values for the maximum load condition derived from the
percentage limits given in table 2 shall not be exceeded;
– in any dimming position, the harmonic current shall not exceed the value of
current allowed in the maximum load condition;
– the equipment shall be tested according to the conditions given in C.5.
b) Active input power ≤25 W
Discharge lighting equipment having an active input power smaller than or
equal to 25 W shall comply with one of the following two sets of requirements:
– the harmonic currents shall not exceed the power-related limits of table 3,
column 2, or:
– the third harmonic current, expressed as a percentage of the fundamental
current, shall not exceed 86 % and the fifth shall not exceed 61 %; moreover,
the waveform of the input current shall be such that it begins to flow before
or at 60°, has its last peak (if there are several peaks per half period)
before or at 65° and does not stop flowing before 90°, where the zero crossing
of the fundamental supply voltage is assumed to be at 0°.
If the discharge lighting equipment has a built-in dimming device, measurement
is made only in the full load condition.
Limits for Class D equipment
For Class D equipment, the harmonic currents and the power shall be measured
as defined in 6.2.2. The input currents at harmonic frequencies shall not
exceed the values that can be derived from table 3 according to the
requirements specified in 6.2.3 and 6.2.4.
Table 1 Limits for Class A equipment
Table 2 Limits for Class C equipment
Table 3 Limits for Class D equipment
