Transformers

Transformers are an essential component of electrical systems and are used to transfer electrical energy from one circuit to another through electromagnetic induction. They come in different sizes, shapes, and types, and are used in a variety of applications including power generation, distribution, and transmission.

How can GTG assist you with the tests on transformers?

(1) Electrical safety test

• Insulation resistance test: the test is to ensure that the transformer insulation is intact and that there are no electrical leaks. This test involves applying a high DC voltage between the transformer windings and the ground and measuring the current that flows through the insulation. The results of this test are usually expressed in megohms, and a low reading indicates that there is a problem with the insulation.

• Polarity test: the test to ensure that the primary and secondary windings are correctly connected. This test involves applying a low voltage AC signal to the primary winding and measuring the voltage on the secondary winding. The results of this test are usually expressed in terms of the transformer’s polarity, which can be either additive or subtractive.

• Short circuit test: the test is to determine the transformer impedance and power loss under short circuit conditions. This test involves applying a low voltage AC signal to the primary winding and then short-circuiting the secondary winding. The results of this test are usually expressed in terms of the transformer’s impedance and power loss, which are important parameters for determining the transformer’s efficiency.

• Open circuit test: the test is to determine the transformer no-load losses. This test involves applying a low voltage AC signal to the secondary winding and measuring the voltage and current on the primary winding. The results of this test are usually expressed in terms of the transformer’s no-load losses, which are an essential parameter for determining its efficiency.

• Dielectric withstand test: the test is to ensure that the transformer can withstand high voltage surges without insulation breakdown. This test involves applying a high AC voltage between the transformer windings and the ground for a specified period and then measuring the current that flows through the insulation. The results of this test are usually expressed in terms of the transformer’s insulation resistance, which should be high enough to prevent electrical leaks.

• Voltage ratio test: the is to ensure that the transformer voltage ratios are within their specified limits. This test involves applying a low voltage AC signal to the primary winding and measuring the voltage on the secondary winding. The results of this test are usually expressed in terms of the transformer’s voltage ratio, which should be within its specified limits.

• Induced voltage test: the test is to ensure that the transformer can withstand high voltage surges without insulation breakdown. This test involves applying a high voltage AC signal to the primary winding and measuring the voltage induced on the secondary winding. The results of this test are usually expressed in terms of the transformer’s insulation resistance, which should be high enough to prevent electrical leaks.

• Winding resistance test: the test is to ensure that the transformer windings have the correct resistance values. This test involves measuring the resistance of each winding using a low voltage DC signal. The results of this test are usually expressed in terms of the transformer’s winding resistance, which should be within its specified limits.

(2) EMC test

• Radiated emissions (RE) test: the test is performed to detect the level of electromagnetic radiation emitted from the transformer. The test is carried out in an anechoic chamber, and a spectrum analyzer is used to measure the radiation level. If the transformer fails to meet the specified limits, it is retested with additional measures to reduce the emissions.

• Conducted emissions (CE) test: the test is carried out to detect the level of electromagnetic noise transmitted through the power cord. The transformer is connected to a spectrum analyzer through a LISN (Line Impedance Stabilization Network) and tested for its noise level. If the noise level exceeds the specified limits, additional measures are taken to reduce the noise.

• Electrostatic discharge (ESD) test: the test is carried out to determine the transformer’s susceptibility to electrostatic discharge. The transformer is tested by discharging a high voltage pulse onto its surface and measuring the response. If the transformer fails to meet the specified limits, additional measures are taken to improve its ESD immunity.

• Radiated immunity (RI) test: the test is carried out to determine the transformer’s ability to withstand electromagnetic radiation. The transformer is exposed to high levels of electromagnetic radiation, and its performance is measured. If the transformer fails to meet the specified limits, it is retested with additional measures to improve its immunity.

• Conducted immunity (CI) test: the test is carried out to determine the transformer’s ability to withstand electromagnetic noise transmitted through the power cord. The transformer is connected to a spectrum analyzer through a LISN, and its response to electromagnetic noise is measured. If the transformer fails to meet the specified limits, it is retested with additional measures to improve its immunity.

• Surge immunity test: the test is carried out to determine the transformer’s ability to withstand voltage surges. The transformer is subjected to high voltage surges, and its response is measured. If the transformer fails to meet the specified limits, additional measures are taken to improve its surge immunity.

• Magnetic field immunity test: the test is carried out to determine the transformer’s ability to withstand magnetic fields. The transformer is exposed to high levels of magnetic fields, and its response is measured. If the transformer fails to meet the specified limits, additional measures are taken to improve its magnetic field immunity.

• Voltage dips and interruptions test: the test is carried out to determine the transformer’s ability to withstand voltage dips and interruptions. The transformer is subjected to varying voltage levels, and its response is measured. If the transformer fails to meet the specified limits, additional measures are taken to improve its voltage dip and interruption immunity.

• Harmonic current emissions test: the test is carried out to determine the transformer’s harmonic current emissions. The transformer is connected to a spectrum analyzer through a LISN, and its harmonic current level is measured. If the transformer fails to meet the specified limits, additional measures are taken to reduce its harmonic current emissions.

• Flicker test: the test is carried out to determine the transformer’s flicker level. The transformer is subjected to varying loads, and its flicker level is measured. If the transformer fails to meet the specified limits, additional measures are taken to reduce its flicker level.

• Transient immunity test: the test is carried out to determine the transformer’s ability to withstand transient voltage spikes. The transformer is subjected to high voltage spikes, and its response is measured. If the transformer fails to meet the specified limits, additional measures are taken to improve its transient immunity.

• Power frequency magnetic field immunity test: the test is carried out to determine the transformer’s ability to withstand power frequency magnetic fields. The transformer is exposed to high levels of power frequency magnetic fields, and its response is measured. If the transformer fails to meet the specified limits, additional measures are taken to improve its power frequency magnetic field immunity.

(3) Mechanical tests

• Vibration test: the test is conducted to check the transformer’s ability to withstand vibrations during transportation or operation. The transformer is subjected to various frequencies and amplitudes of vibrations, and its performance is checked for any damages or changes.

• Mechanical shock test: the test is conducted to check the transformer’s ability to withstand mechanical shocks during transportation or operation. The transformer is subjected to various levels of mechanical shock, and its performance is checked for any damages or changes.

• Tensile test: the test is performed to measure the transformer’s ability to withstand tensile stress during transportation and installation.

(4) Environmental tests

• Temperature rise test: the test is conducted to test the transformer’s ability to withstand high temperatures. The transformer is loaded with its rated power and its temperature is measured at various intervals. If the temperature rise is within the specified limits, the transformer is considered to be suitable for operation.

• Humidity test: the test is conducted to check the transformer’s ability to withstand high humidity levels. The transformer is subjected to high humidity levels, and its performance is checked for any damages or changes.

• Rain test: the test is conducted to check the transformer’s ability to withstand rainy environments. The transformer is subjected to high levels of rain, and its performance is checked for any damages or changes.

• Corrosion test: the test is conducted to check the transformer’s ability to withstand corrosive environments. The transformer is subjected to high levels of corrosive substances, and its performance is checked for any damages or changes.

How can GTG assist you with the certifications or markings for transformers?

 (1) IEC certification

IEC (International Electrotechnical Commission) certification is a globally recognized certification that ensures that the transformer meets specific safety, performance, and environmental standards.

(2) CE marking

CE certification is a mandatory certification for transformers sold in the European Union. It ensures that the transformer meets the European Union’s safety, health, and environmental protection requirements.

(3) UL certification

UL (Underwriters Laboratories) is a global safety certification organization that tests and certifies transformers to ensure they meet specific safety standards. UL certification is widely recognized in the United States and Canada, and it is often required by insurance companies and regulatory agencies.

(4) CB certification

CB (Certification Body) certification is a global certification that ensures that the transformer meets specific safety, performance, and environmental standards.

(5) CSA certification

This is a certification from the Canadian Standards Association, which is an organization that develops standards and tests electrical equipment for safety and performance.

(6) ETL Listed mark

The ETL Listed Mark is a certification for transformers that are tested and compliant with North American safety standards. This certification ensures that the transformer is safe for use in various applications.

(7) RoHS certification

The Restriction of Hazardous Substances (RoHS) certification ensures that the transformer does not contain any harmful substances such as lead, mercury, or cadmium. RoHS compliance is mandatory for transformers sold in the European Union.

(8) REACH certification

The Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) certification ensures that the transformer does not contain any harmful chemicals. REACH compliance is mandatory for transformers sold in the European Union.

(9) Energy Star certification

The Energy Star certification is awarded to transformers that meet the energy efficiency requirements set by the US Environmental Protection Agency (EPA). This certification ensures that the transformer is energy-efficient and reduces greenhouse gas emissions.

(10) CCC certification

The China Compulsory Certification (CCC) mark is mandatory for transformers sold in China. This certification ensures that transformers meet the safety and performance standards set by the Chinese government.

(11) PSE certification

This is a certification from the Product Safety Electrical Appliance and Material Safety Law, which is a mandatory certification system that tests and certifies electrical equipment for safety and performance in Japan.

(12) JIS certification

JIS (Japanese Industrial Standards) certification is a Japanese certification that ensures that the transformer meets specific safety, performance, and environmental standards.

(13) VDE certification

This is a certification from the Verband Deutscher Elektrotechniker, which is an organization that tests and certifies electrical equipment for safety and performance in Germany.

(14) GOST-R

GOST is a certification from the Gosstandart, which is an organization that tests and certifies electrical equipment for safety and performance in Russia. The GOST-R certification is mandatory for transformers sold in Russia and other CIS countries. It ensures that the transformer meets the necessary safety and performance standards and is suitable for use in power systems.

(15) KEMA-KEUR certification

This is a certification from the KEMA, which is an organization that tests and certifies electrical equipment for safety and performance in the Netherlands.

(16) SII certification

This is a certification from the Standards Institution of Israel, which is an organization that tests and certifies electrical equipment for safety and performance in Israel.

(17) SASO certification

This is a certification from the Saudi Arabian Standards Organization, which is an organization that tests and certifies electrical equipment for safety and performance in Saudi Arabia.

(18) BIS certification

This is a certification from the Bureau of Indian Standards, which is an organization that tests and certifies electrical equipment for safety and performance in India.

(19) WEEE compliance

WEEE (Waste Electrical and Electronic Equipment) compliance ensures that the transformer can be safely disposed of at the end of its life cycle.

(20) NEMA certification

NEMA (National Electrical Manufacturers Association) certification is a North American certification that ensures that the transformer meets specific performance, safety, and environmental standards.

(21) S mark

This is a certification from the Standards Association of Australia, which is an organization that tests and certifies electrical equipment for safety and performance in Australia.

Why the biggest brands trust GTG Group?

GTG Group (Global Testing Group) is a certification company that offers testing and certification services to different industries. Our expertise in transformer testing and certification has made us a trusted name in the industry.

(1) Independent and impartial testing

GTG Group is a third-party testing company, which means we are not affiliated with any specific manufacturer. This impartiality can provide camera manufacturers and consumers with confidence in the accuracy and reliability of the testing process, and ensure that the camera meets the required standards.

(2) Confidentiality and security

GTG Group understands the importance of confidentiality and security when it comes to testing and certification. We ensure that our clients’ data and information are kept confidential and secure at all times. This ensures that our clients’ intellectual property and trade secrets are protected.

Contact GTG Group today for transformer testing and certification to avoid any legal issues that may arise from using a faulty transformer.