What is EMC?

EMC (Electro Magnetic Compatibility) is ability of an equipment or system to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment. Thus, EMC includes to two aspects: one is the electromagnetic interference caused by equipment during the normal operation can not exceed a certain limit for that environment; the other side is appliance shall has capacity of resisting disturbance to electromagnetic environment, that is Electromagnetic susceptibility.

EMC includes EMI (interference) and EMS (susceptibility). EMI (electromagnetic interference) describes the electromagnetic disturbances caused by electric and electronic appliances in normal operation to environment, which includes CE (conduction emission), RE (radiation emission) and harmonic tests. EMS (electromagnetic susceptibility) describes if the electric and electronic equipment will be disturbed by other appliance in same circuit or in surroundings. EMS includes ESD (elestrostatic discharge), CS , RS (Radiation interference), EFT (electrical fast transient), surge (lightning surge), voltage dip and interrupt and etc.

Like household appliance, the EMC test requires two aspects, EMI and EMS.

EMI test items includes:

1) Continuous interference voltage (150KHz~30MHz)

2) Disturbance power: 30MHz~300MHz)

3) Harmonic current (2~40 times harmonic)

EMS test items includes:

1) Electrostatic discharge immunity measurement

2) Radiation field (80MHz~1000MHz) immunity measurement

3) Electrical fast transient/burst group immunity measurement

4) Lightning surge immunity measurement

5) Injection current (150KHz~230MHz) immunity measurement

6) Voltage dip and short interruption immunity measurement

In China, the key parts of household appliance request to do EMC testing, the list as below:

Air conditioner: compressor, PC control board (includes frequency convertor), anion generator, power filter

Refrigerator: compressor, PC control board (includes frequency convertor), power filter, mechanical temperature controller

Washing machine: programming controller (includes timer), computer controller, power filter, motor

Electric cooker: temperature controller, computer controller, electric hot tray

Electric iron: galvanothermy tube, temperature controller

Electric fan: computer controller, motor

Electric hair drier:motor, filter, speed controller

Pego released part of EMS equipment, includes ESD generator, EFT generator, lightning surge generator, voltage dip and short interruption generator and ring wave generator. Those equipment can help the electrical and electronic equipment manufacturers to improve the quality of their products in the loop of design and R&D.