AMETEK CTS 3.0 - Manual (Page 86)

Compliance Test System 3.0 User Manual
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6. Flicker Testing
6.1 About This Chapter
This chapter covers testing a device for compliance with the IEC 61000-3-3 Flicker standard. The
relevant IEC Flicker test part is described in detail.
6.2 Principle of Operation
The CTS Flicker software acquires, stores, processes and analyzes the EUT data in real-time and
provides continuous display updates on all Flicker parameters. Voltage time domain data is
collected, the rms voltage value is calculated for each half period of the signal or every 10
mseconds, and the measurement data is written to disk for 100 consecutive acquisition periods or
once every second.
This allows the operator to monitor the progress of the flicker test and, should a failure occur
before the end of the test run, abort the test if needed. Since flicker test can run for several hours,
this will avoid needless waiting for tests to finish on a EUT that already failed the IEC
requirements.
In order to run the real-time Flicker test, you need a 2.0 GHz Pentium PC or better. This is caused
by the amount of data that needs to be processed to perform flicker eval
uation. Slower PC‟s will
not be able to process the data in real-time.
6.3 Flicker Test Options
The CTS Flicker test mode supports several test modes. These modes allow the user to select
the flicker parameters that shall be used to determine a PASS or FAIL result. Some types of EUT
may not need to be evaluated for Plt since they are unlikely to cause long-term flicker. This is
largely a function of the operating cycle of the equipment being evaluated. Consult Annex A of the
IEC 61000-3-3 test standard to determine which test option is most appropriate for the EUT under
evaluation. The following options are available
Mode Description
Test all Flicker parameters This is the default test mode and should be used if you are
unsure about the typical operating cycle of the unit under
test.
Test dc, dt, dmax and Pst only This mode only tests for compliance to the dc and dt
specifications.
Test dc, dt and dmax only This mode only tests for short-term flicker. It can be used to
test equipment that has operating cycles less than 2 hours.
Several levels of dmax may be permissible depending on
the EUT. The selection criteria are as follows:
The maximum relative voltage change d max , shall not
exceed
a) 4 % without additional conditions;
b) 6 % for equipment which is
– switched manually, or
– switched automatically more frequently than twice per
day, and also has either a delayed restart (the delay being
not less than a few tens of seconds), or manual restart,