Introduction of measurement standard
Standard name: GB17625.1-2003 idt IEC 61000-3-2:2001 (Electromagnetic compatibility limits and Harmonic current emission limits (each phase input current ≤16A))
GB17625.1-2003 is one of the important standards among many electronic products certification testing. This standard measures and limits the power supply current waveform distortion degree when using the electronic and electrical products powered by the low voltage utility (each phase input current ≤16A).
GB17625.1-2003 standard limits the equipment current waveform distortion by limiting the high time harmonic component of the equipment current. GB17625.1 includes the 40 times harmonic current content. (Harmonic Analyzer)
This standard only has the harmonic current limits requirements for the equipment with 50Hz/60Hz access frequency, 220V/230V/240V phase voltage and low voltage power supply system as well as less than 16A input current.
This standard is a general emc standard. There are many products that are suitable for this standard including the household appliances, electric power tool, electrical lighting equipment, information technological equipment and sound and imaging equipment.
The classification is based on the different harmonic current value.
Class A: balanced three-phase equipment
Household appliance doesn’t include the equipment of class D;
Tool doesn’t include the portable dam;
Incandescent lamp dimmers
Audio frequency apparatus
other equipments except the following classes.
Class B: portable dam: arc welding equipment that doesn’t belong to the special equipment.
Class C: lighting equipment
Class D: equipment with less than 600W active power including the personal computer and personal computer monitors and television receiver.
Harmonic current limits
The following types of equipment limits are not specified in the standard.
Equipment with less than 75 W rated power, except the lighting equipment (this value may reduce from 75W to 50W);
the specified equipment with more than 1kw total rated power;
Symmetrical control heating elements with more than 200 W rated power;
Incandescent lamp independent dimmers with less than 1kw rated power.
(Usually, the manufacturers use this limit to avoid the harmonic current limit)
Harmonic current limits of class A equipment
See the harmonic current limits of class A equipment in the corresponding form, the limit value is the effective value, the unit is ampere. This limit value is the fixed value, which is not related to the power of the product and the fundamental current.
Harmonic current limits of class B equipment
The harmonic current value of Class B equipment is 1.5 times of class A equipment.
Harmonic current value of Class C equipment
a) Active input power is more than 25W
For the lighting electrical appliances with more than 25W active input power, the harmonic current should not be more than the relevant limit value of Class C equipment. This limit value is not related to the product fundamental wave current.
b) 25W Active input power is less than 25W
For the discharge lamp with less than 25W active power, the standard stipulates the specified qualified determination conditions.
Harmonic current limit value of Class D equipment
a) Only limit odd harmonic current
b) Odd harmonic current not only conforms with the maximum allowed harmonic current, but also conforms with the maximum harmonic current allowed by each watt
Class D equipment has rather strict requirement, the harmonic current of Class D equipment is rather huge.