E-Mon E-PS-S-HV-RTU - Manual (Page 222)

Appendix F EN50160 Evaluation and Recording
222 PowerSmart Socket Power Quality Meter
clears the evaluation registers and counters so that each
evaluation period’s statistics is stored in a separate record.
You can upload and view the online statistics data via Power
Software reports, using data collected since the beginning of
the present evaluation interval. You can also manually clear
the present contents of the counters though Power Software
before starting your EN50160 evaluation.
Observation Period
The observation period is the period of time within which the
voltage
characteristics shall be assessed to ensure
compliance with the standard. The observation periods
declared by the EN50160 may differ for characteristics for
which compliance limits are specified in the standard, usually
one week, and for those for which only indicative values are
provided, usually one year.
The EN50160 compliance reports produced by Power
Software provide correct weekly and yearly observation
statistics regardless of the evaluation periods used for
collecting data. Whenever needed, Power Software will
aggregate records within a number of the evaluation intervals
to provide correct observation periods. Some of the
characteristics, like rapid voltage changes or mains signaling
voltage, may require daily assessments. If you intend to use
daily-evaluated voltage characteristics, select the daily
evaluation period via the EN50160 Advanced setup.
Methods of Evaluation
This section describes methods used by the PowerSmart
Socket PQM for evaluating supply voltage characteristics to
ensure compliance with the standard.
Frequency Variations
Method of Evaluation
The basic frequency measurement is the mean value of the
frequency over fixed time intervals of 10 seconds under
normal operating conditions.
A frequency variation is not evaluated if the supply voltage
crosses a voltage tolerance limit (±15% Un).
Target Values
The ranges of frequency variations given in the EN50160 are:
• 50Hz±1% for 95% of a week
• 50Hz±1% for 99.5% of a year
• 50Hz+4/-6% for 100% of the time
The same limits are used for 60Hz systems. The frequency
compliance limit can be programmed in the meter in percent
of the nominal power frequency via the EN50160 PQ Recorder
setup.