IEC 61000-4-28 establishes a reference for evaluating the immunity of electric and electronic equipment when subjected to variations of the power frequency. Only conducted phenomena are considered, including immunity tests for equipment connected to public and industrial networks.
This standard applies to electric and/or electronic equipment connected to 50 Hz or 60 Hz distributed network with rated line current up to 16 A per phase.
It does not apply to electric and/or electronic equipment connected to AC 400 Hz distribution networks. Tests concerning these networks will be covered by other IEC standards.
In general, electrical and electronic equipment is not susceptible to minor variations of the power frequency. Testing according to this standard should be limited to products that are assessed to be susceptible to power frequency variations by design, environment or failure consequences.
The immunity test levels required for a specific electromagnetic environment together with the performance criteria are indicated in the product, product family or generic standards as applicable.