AMETEK MX CTSH User Manual
Page 21
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California Instruments
Revision H
21
User Manual
MX Series CTSH Compliance Test System
2.5.2
When to Test for IEC 61000-3-11
As mentioned, it may not be necessary to test every product for IEC 61000-3-11. If the maximum RMS
current per phase of the EUT is less than 16 Arms per phase, the IEC 61000-3-3 test should be used.
(Requires optional CTSMXL Software CIC652) For loads having an rms current draw of more than 16
Amps per phase, it is generally recommended to verify conformance to IEC 61000-3-11 however unless the
EUT passes under IEC 61000-3-3.
2.6
EN 61000-4-11p Voltage Dips and Variations
The EN 61000-4-11 is an immunity test for low voltage equipment to ensure reliable operation when
connected to the public distribution system. This test requires an AC source that is capable of generating
specific voltage variations and voltage dips. The unit under test must not sustain any damage from such
occurrences nor cause unsafe conditions.
Table 2-6: Average public utility disturbances per annum in Europe
DEPTH
DURATION
(Voltage drop in % of
nominal Ut)
10 to < 100 ms
100 to < 500
ms
500 ms to 1
sec
1 sec to > 3
sec
10 %o < 30 %
61
66
12
6
30 % < 60 %
8
36
4
1
60 % < 100 %
2
17
3
2
100 %
0
12
24
5
Number of disturbances per year
The need to test for immunity of products against voltage dips and interruptions was prompted by studies of
electric utility availability. The results shown in Table 2-6 were found in this study (UNIPEDE study 91 en
50.02). From this data it is clear that most disruptions are short in nature (about 5 to 10 periods) and no
more than 60 % below nominal. Occasionally however, extended periods of complete power loss occur. It is
suggested that this test data also be used as a guide in selecting appropriate test levels.
2.6.1
Why Do You Have to Test?
The EN 61000-4-11 affects a large set of products, specifically; "Electrical and electronic equipment having
a rated input current not exceeding 16 A per phase." Thus, most single and three phase AC powered
equipment used in domestic and light industrial settings fall in this category. In fact, around 95 % of all
electrical equipment in household and light industrial applications, require no more than 16 A per phase. In
Europe, this implies real apparent levels of 230 V * 16 A = 3680 VA, with real power either at the same or a
lower level. Specifically excluded are all DC powered products (battery operated devices) and 400 Hz AC
equipment. (Avionics) These products will be covered in future IEC standards. At this time meeting the EN
61000-4-11 standard is required for most products to obtain the CE Mark, required to market products in
the European Union.
California Instruments’ MXCTS system supports pre-compliance EN 61000-4-11 testing using the MX
Series AC power source with the addition of the -411 firmware option. The test sequencer and report
generation for EN 61000-4-11 is provided through the MXGUI Windows
→
software. To
accommodate changes in the specification, test levels and duration can be set by the operator or
loaded from disk if needed.