Household electronic devices are an integral part of our daily lives, but they can also be a source of electromagnetic interference (EMI) while working and potential harm to nearby electronic devices. Also, often, the household device may be affected by EMI from various surrounding sources, such as power lines and other nearby electronic devices. To ensure that household equipment is safe and reliable to use, it is important to subject it to electromagnetic compatibility (EMC) testing. 

What is EMC testing?

EMC testing is the process of evaluating a product's ability to function as intended in the presence of electromagnetic fields and to ensure that it does not generate harmful electromagnetic emissions. 

EMC testing typically involves two types of tests: emissions testing and immunity testing. Emissions testing is used to measure the amount of EMI emitted by a device, while immunity testing is used to measure the device's ability to resist EMI from external sources. The EMC testing is conducted in a laboratory environment by using specialized equipment, such as an EMC test chamber and other supporting EMC testing instruments.  

Why is EMC testing important for household equipment?

Household equipment is often affected by EMI from various sources, such as power lines and other nearby electronic devices. If a product is not properly tested for EMC, it could experience performance degradation, malfunctions, or complete failure when exposed to these types of EMI sources. In addition, household equipment that generates harmful electromagnetic emissions can interfere with other nearby electronic devices and potentially cause damage or malfunctions. 

Hence, EMC testing is necessary to ensure the product does not emit more than the electromagnetic energy emission limit specified in the EMC standards and ensure the product has the capability to withstand electromagnetic interference from other sources that will occur while working in the intended real-time environment. 

How is EMC testing performed on household equipment?

The EMC testing process involves determining the product's susceptibility to EMI and measuring the levels of electromagnetic emissions it produces. This can be done in a laboratory setting using specialized equipment, such as an EMC test chamber. EMC testing involves electromagnetic energy emission levels measurement tests and immunity tests. 

Understanding conducted (via cable) & radiated emission (via air), conducted (via cable) & radiated immunity test (via air)

There are several different types of EMC tests that may be performed on household equipment, including:

Radiated emissions (RE) measurement test:

This test measures the levels of radiated electromagnetic energy emitted by the product while working. This test ensures that the product does not emit more than the radiated emission limit specified in the EMC standards.  

Conducted emission (CE) measurement test:

This test measures the levels of conducted EMI emitted by the product while working. The CE test ensures that the product does not emit more than the conducted EMI emission limit specified in the EMC standards. 

Conducted EMI is unwanted electromagnetic emissions (EMI) from devices while working that propagate through the power cord or power line and may affect the other connected devices on the same line.

Radiated immunity (RI) test:

Tests the product's ability to withstand radiated EMI from various sources, such as power lines and other electronic devices. 

In this test, the device's immunity to radiated EMI is tested by intentionally applying a significant level of radiated EM field energy (test signals). This immunity test ensures that the product can withstand the radiated EMI from other electromagnetic sources, such as power lines & other electronic devices that the device will encounter while in normal usage.

Conducted immunity test:

Tests the product's ability to withstand conducted EMI that are conducted through power lines or other cables. 

In this test, the device's immunity to conducted EMI is tested by intentionally applying a significant level of test signals via cable into the equipment under test (EUT).  This immunity test ensures that the product can withstand the conducted EMI from other electromagnetic sources, such as power lines & other electronic devices that the device will encounter while in normal usage. 

Electrostatic Discharge: This is an immunity test to test the product's ability to withstand electrical discharge, such as a static electricity shock.

The EMC testing is performed as per EMC standards in a laboratory environment. EMC standards define terms, EMC test methods, rules, emission limits, and immunity levels for Electromagnetic Compatibility (EMC). Once the testing is complete, the results are analyzed to determine if the product meets the required EMC standards and specifications. If the product does not meet the standards, the manufacturer may need to make changes or modifications to improve its EMC performance. 

Different Test Standards for Household Appliances EMC Testing

There are several EMC testing standards for household compliance, depending on the specific product and market it is intended for. Some of the most common standards are:

FCC Part 15: This is a set of regulations from the Federal Communications Commission (FCC) that sets limits on electromagnetic interference (EMI) that can be produced by electronic devices.

EN 55032: This is a European standard that sets limits on EMI emissions for multimedia equipment.

CISPR 32: This is an international standard that sets limits on EMI emissions for multimedia equipment.

CISPR 11: This is an international standard that sets limits on EMI emissions for industrial, scientific, and medical (ISM) equipment.

IEC 61000-3-2: This is an international standard that sets limits on harmonic currents produced by electrical equipment connected to the low-voltage power supply network.

IEC 61000-3-3: This is an international standard that sets limits on voltage fluctuations and flicker in low-voltage power supply networks.