IEC61000-4-27

This unbalance immunity test aim to test the immunity of an electric or electronic device against unbalance in three phase.

Test Setup

Set the following test conditions before starting a test. Depending on the Test, some settings are fixed and you cannot change them.

EUT Test	For Standard Test, select the Equipment Under Test (EUT) class and Test Level. The EUT class determines the test levels used . Products are categorized into four classes, 1, 2, 3 and X, with X being a class defined and customized by users. For equipment connected directly or indirectly to the public network, the levels shall not be less severe than class 2. Test levels for class 1 and X are not specified in the standard itself. Testing levels for these classes are defined in product specific IEC standards which refer to the generic standard for test methods and equipment to be used.
UN (Phase) (V)	Set the rated voltage of the EUT. The voltage range for immunity tests are: AC – 0.0 to 322.0 V DC – 0.0 to 455.0 V In some cases, the test is unsuccessful due to the output voltage exceeded the output voltage range of the instrument. You may need to adjust the UN, Udc, UT, U1, Delta, and/or Level settings and run the test again.
Freq (Hz)	Set the rated frequency of the EUT.
Phase Reference	Select the phase that will be used as the reference for setting Ua, Ub, or Uc.
Repeat	Set the number of repetitions of the sequence (1 to 999).
Status	Display results upon completion of the sequence.
TriggerOut	Select the check box to enable the trigger signal output. When enabled, the corresponding arrow in the Test Steps diagram will change to red.

Set the following test parameters for a sequence. For Standard Test, the test parameters are fixed and you cannot change them.

Amplitude, Un (%)	Set a ratio of a quantity to the rated voltage of the EUT. The positions where Ua, Ub, and Uc are displayed vary depending on Phase Reference setting.
Phase angle with respect to Ua/ Ub/ Uc (°)	Set the phase angle (0.0° - 359.0°). The suffixes (phase pairs) that are displayed vary depending on Phase Reference setting.
Duration (s)	Set the step execution time in seconds (0.001 to 86,400.000 s).
Interval (s)	Set the repetition interval of unbalance (0.000 to 86,400.000 s). In this period, each phase voltage is set to 100 %, the ab phase angle is set to 120°, and the ac phase angle is set to 240°.
(at the right corner of the Test Steps panel)	This setting is only available for Custom Test. Set the phase starting angle (Start Phase) and phase ending angle (End Phase). When Start Phase or End Phase is set, the phase angle will offset according to the setting.