The International Electrotechnical Commission (IEC) has released the edition 2 of the IEC62052-11. Release date was 29.06.2020. This edition includes several significant technical changes with respect to the previous edition.
Today we take a closer look at the chapter 9.3.2
Voltage dips and short interruptions
The intent of these tests is to ensure that the meter is immune to dipsWhat is a Voltage Dip Event? and short interruptions that commonly occur on the mains power supply.
The IEC standard provides only a table. To make the requirements more easy to understand, we have converted the table in qualitative graphics. These graphics are showing the number of cycles for AC meters with a nominal frequency of 50 Hz. For the 60 Hz values please take a look at table 16 of the IEC62052-11:2020.
General Conditions
The voltage circuits are energized with their lowest specified nominal voltage and without current.
Additionally, for three-phase meters:
The voltage interruption tests (test 1 … 4) have to be done at the same time for all three phases. The voltage dip tests (test 5 … 9) are done phase by phase (Ph – N). The other phases remain connected to the supply voltage Un.
For three-phase three wire meters the phase-phase voltages are tested. The other phases remain connected to the supply voltage.
Voltage Interruption, Test 1

Voltage Interruption, Test 2

Voltage Interruption, Test 3

Voltage Interruption, Test 4

Voltage Dip, Test 5

Voltage Dip, Test 6

Voltage Dip, Test 7

Voltage Dip, Test 8

Voltage Dip, Test 9

Acceptance Criteria
Simplified
During the test, a temporary degradation or loss of primary functions is acceptable.
Items to monitor for evaluation:
- Energy registration
You read the billing registers before and after each test
The register values are not allowed to change above the critical change valueThe Critical Change Value (x)
x = 10−6 × m × Un × Imax
x = critical change value in kWh or kvarh
m = number of measurement elementsThe different current subscripts
Un = nominal voltage (V)
Imax = maximum current (A) - Indicating display
degradation of display quality during the test is acceptable - Load switch
What is a Load-Switch?
unexpected operation of the switch during the test shall not occur
Thank you for reading. You can leave a comment after the dip.
Editor's note: This article was originally published in July 2020 and has been updated for comprehensiveness.
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