Last revised: December 2011
3
PM220P00_250
PM240P00_250
250
37.83
8.75
30.08
8.26
A PV module may produce more current and/or voltage than reported at STC. Sunny, cool
weather and reflection from snow or water can increase current and power output.
Therefore, the values of Isc and Voc marked on module should be multiplied by a factor of
1.25 when determining component voltage ratings, conductor capacities, fuse sizes, and size of
controls connected to PV output. An additional 1.25 multiplier may be required by the NEC
(National Electric Code) for sizing fuses and conductors as described in the NEC section
690-8.
Performance of PV Modules
A PV module generates current which is proportional to the intensity of solar radiation,
while the voltage varies with cell temperatures.
Note that the cell temperature is usually higher than the environmental temperature. The
increase in the temperature of cell compared to the air temperature depends on the thermal
characteristics of the module.
In summary, depending on solar radiation, the temperature of the cells and the equipment to
which they are connected, a PV module will generate a different current and voltage levels,
which result in a different power output.
Grounding
BenQ Solar PV modules have a clearly marked grounding hole on each side of the frame for
inserting the ground contact. The grounding screw and bolt are separately used from the
mounting parts of the module.
The recommended assembly is shown in Figure 1. Note that the frame is fully insulated by
anodizing. Please make sure the grounding screw removes the anodizing on the surface of the
grounding holes, or scratch off the anodizing before the grounding connection is made. If the
material of support structure is different with the material of frame (aluminum), the Insulation
between them is required. Should the support structure be a non conductor, a cable must be
connected by means of a suitable fastening system. The fastening system will be joined to a
cable with a minimum 2.5mm
2
cross section, together with all the grounding conductors from
each module. Please make sure that each module is grounding properly.
Figure 1 Recommended grounding connection
Cable
Screw
Spring washer
Cup washer
Ground
Ground
Ground
Ground
