METREL EurotestPV Lite, Instruction Manual

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MI 3109 EurotestPV Lite Measurements
52
Notes :

Before starting the PV measurements settings of PV module type and PV test
parameters should be checked.

For calculation of STC results correct PV module type, PV test parameters, Irr
and Tcell values must be measured or be entered manually before the test. The
Irr and T results in ENV. menu are considered. Refer to Appendix E for further
information.

The Irr and T measurements should be carried out immediately before the Uoc /
Isc test. Environmental conditions must be stable during the tests.

For best results PV remote unit A 1378 should be used

Roc is a calculated value based on measured Roc+ and Roc-. Roc+ and Roc-
are measured according to method 1 in the IEC 62446 standard. The calculated
value is based on the electrical substitute model of PV modules and is in general
the same or closes to the insulation resistance that would be measured
according to method 2 in the IEC 62446 standard.
5.9 Measurement of cell temperature before test
The standard IEC 61829 recommends procedure for choosing and recording
appropriate conditions for measurement. One of the recommendations is that the
temperature of the PV array must be equilibrated before the test. In combination with
the PV remote unit A 1378 the instrument enables to store the measured cell
temperatures 0 min, 5 min, 10 min and 15 minutes before PV tests (I/ V curve
measurement, Uoc/Isc test, PV panel test and Auto test).
The cell temperature should be measured with A1378 before the PV test. After
synchronization of results between the instrument and A1378 the instrument enables to
add temperature values before the test to stored I/ V curve, Uoc/Isc, PV panel test and
Auto test results.
The results can be viewed in recall memory screens (see
8.4 Recalling test results for
more information).
Figure 5.45: Example of cell temperature before test result screen
Displayed results:
T15 .......... cell temperature 15 minutes before the PV test
T10 .......... cell temperature 10 minutes before the PV test
T5 ............ cell temperature 5 minutes before the PV test
T0 ............ cell temperature at the moment before the PV test