AMETEK CTS 3.0 - Manual (Page 71)

User Manual Compliance Test System 3.0
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5. Harmonics Testing
5.1 About This Chapter
This chapters covers testing a device for compliance with the IEC 61000-3-2 Harmonics standard.
A review of the possible EUT classes is provided to assist the user in determining the appropriate
device class to use. Once the device class has been established, the appropriate test module is
used to perform the tests.
5.2 Test Standard Selection
Before running any Harmonics test, you must decide if you want to test to the old harmonics
standard (IEC 61000-3-2:1998, includes Amendments 1 and 2) or the new one. (IEC 61000-3-
2:2000, Amendment 14). Both may be used up to January 2004 after which time only the new
standard should be used. The standard selection is made in the lower right hand corner of the
setup screen. Once selected, some options may be grayed out. For example, the new test
standard only considers transitory harmonics so the quasi-stationary selection is disabled. Note
that the acquisition window over which the evaluation of current harmonics is made differs under
both standards. Per the IEC 61000-4-7 referenced in Amendment 14, which replaces the Annex B
of the 1998 standard, the evaluation window for Amendment 14 is 10 cycles at 50 Hz or 12 cycles
at 60 Hz. The 1998 standard is based on an evaluation window of 16 cycles for 50 Hz. (same 16
cycles is used when the frequency is set to 60 Hz). Selecting the desired test standard
automatically configures the CTS for the correct acquisition window.
5.3 Device Classes
The IEC 61000-3-2 categorizes products in one of four product classes. Using the correct class is
important as the harmonic current limits for each class are different. Choosing the wrong class
can mean rejecting a product that otherwise would have passed (False Negative) or passing a
product that normally would have failed (False Positive). Either outcome is undesirable.
The following device classes are defined:
Class A All motor driv en equipment, most “domestic” appliances and virtually all 3
phase equipment (<16 A rms per phase).
Class B All portable electric tools.
Class C All lighting products, including dimmers, with an active input power above
25 Watts.
Class D Products having a power range from 75 to 600 Watts AND a current
waveform that has a special wave shape. For testing to IEC 61000-3-
2:2000, Amendement 14, the special waveshape does not apply and only
TV's PC's and PC Monitors with power levels between 75 and 600 W are
considered class D. All other products are class A.