Dulas Solar VC150, Handbook

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6: OPEN AND SHORT CIRCUIT MEASUREMENTS ON THE PHOTOVOLTAIC
ARRAY
Two simple measurements are possible to show whether a photovoltaic array is
prating correctly. These are the measurement of SHORT CIRCUIT CURRENT AND
OPEN CIRCUIT VOLTAGE.
Measurements are made as follows:
6.1
Using a millimeter or voltmeter to measure open-circuit voltage (Voc)
1.
To test the solar array or one of the solar module in the array, you need to be
able to measure the open-circuit voltage (Voc).
2.
Measure Voc at around 12 noon on a very sunny day.
3.
Voc is the voltage across the two output terminals when no electrical current
is flowing. So you must disconnect one wire from the terminals. If you are
measuring Voc for the solar array, disconnect one solar array output wire from
the terminal box .If you are measuring Voc for one of the solar modules,
disconnect the module from the solar array at the module box.
4. After you have disconnected the output wires, measure the voltage across
solar array or module output terminals.
5. Reconnect the wires to the correct terminals after you have finished.