What is Voltage Drop Testing?
Editorial Team - EMC Directory
Voltage drop testing is a method of diagnosis to locate high resistance problems in a circuit. This testing helps ensure that the equipment can function properly (as expected and safely) even during power supply fluctuations. Sudden voltage dropouts or dips can result in rise in temperature, vibrations, or even shocks to the equipment under test (EUT). Along with voltage drops, this type of testing is used to test the voltage, dips, sags, brownouts, swells, voltage variations, dropout,s and interruptions.
The IEC 61000-4-11(Voltage Variations Immunity Tests) is an EMC standard by the International Electrotechnical Commission for testing and measurement techniques for voltage dips, short interruptions, and voltage variations. This standard specifies the tests, procedures, and limits for voltage dips, dropouts interruptions, and variations of electrical and electronic equipment working on an AC supply having a rated input current not exceeding 16 A per phase with 50 to 60 Hz.
The equipment used for voltage drop testing is:
The test generator and EUT are connected to the AC mains. The test generator controls the dip level, and length of the dip and switches between 100% and the dip signal to create the momentary drop in voltage. As per IEC 61000-4-11, each test-voltage dip has to be repeated three times with a 10-second interval between each voltage drop. The EUT is run on its normal operating modes with all of its normal loads. After each voltage dip or interrupt a complete functional check-up of EUT is performed to note any discrepancies.