Solmetric PVA-1000S, Руководство пользователя

Страница: 106 / 152

4 Making Measurements
4-6
Connect the test leads to the PV equipment
Be sure to observe the correct polarities (connect the red test lead to DC positive, and the
black test lead to DC negative).
If you will be measuring circuits at a combiner box, after lifting all the fuses, you can
connect the PVA test leads to the positive and negative buss bars. This allows you to
insert one string fuse at a time to select the PV circuit you want to test.
If measuring circuits in parallel (for example, strings that are ‘harnessed’ in parallel out
in the array), make sure the combined current is within the specified current range of the
I-V Measurement Unit. Note that in some locations, the irradiance can greatly exceed
1000 watts per square meter. If that is the case and the modules are directly facing the
sun, the string currents can be significantly higher than the STC currents listed on the PV
module label.
Select the first PV circuit to be measured
If you are using the string fuses to select PV circuits, insert the first fuse.
Make your first measurement
Refer to Figure 55.
Figure 55. Results of an I-V curve measurement
Press the Measure Now button. The measured trace will typically appear in 5-20
seconds.
After the measured I-V curve trace appears, the I-V graph slides to the left and the PV
system Array Tree appears at its right.