2
Risk of death by electric arc!
A deadly electric arc can result when opening a closed section (e.g. when separating the DC cable from the inverter
under load):
Never separate the solar generator from the invertor if the latter is connected to the grid!
Working on the roof
Please observe the applicable accident prevention regulations. Do not carry out installation work when there are strong
winds. Secure yourself and other persons from falling down. Prevent objects from potentially falling down. Secure the
work area so that no other persons can be injured.
2. General information on PV plants
Orientation
The solar module achieves the highest yield when oriented to the south (towards the north when in the southern
hemisphere). The optimum angle of inclination outside the tropics can be estimated using the following equation:
Angle of inclination = latitude of the installation site - 20°
Deviations from the optimum orientation and inclination of the modules lead to a reduction in yield.
The minimum inclination is 3°.
Angle of inclination >75° may lead to regional restrictions.
Location
The area planned for the installation should be as free as possible from shade of any kind (houses, trees, branches,
chimneys, dormers, antennas, satellite dishes, cables, etc.), because shade can significantly reduce the efficiency of the
solar modules. Core shadows should be avoided. Even partial shading will lead to a significant reduction in yield. A
module is considered “shade-free” when the entire surface is shade-free all year round and, even on the most
unfavourable days of the year when the sun is low, receives unobstructed sunlight for several hours.
Rear ventilation
The output of solar modules decreases considerably as the modules heat up. Rear ventilation avoids yield-impairing
heat accumulation. The so-called “chimney effect” (draught behind the modules) should not be impeded if possible
(e.g. roof windows, collectors).
Cleaning/Maintenance
With a sufficient inclination of the modules (>20°), there is a self-cleaning effect from rain and snow. Cleaning the
modules is generally unnecessary. In the case of a smaller inclination, the self-cleaning effect is only limited.
However, the soiling of the modules is strongly dependent on the surrounding environment and should be checked once
a year. In case of heavy soiling, it is recommended that the modules be cleaned after cooling down (e.g. in the morning)
using plenty of lukewarm, de-mineralised water and a gentle cleaning device, as sharp-edged items might lead to
scratches on the surface or to destruction of the anti-reflective (AR) coating. Clean, lint-free cotton, microfibre cloths
or paper towels should be used for cleaning. Fatty or oily deposits can be removed with isopropyl or isopropyl/water
mixtures. You should also refrain from using strong acids, alkalis, benzine-based cleaning agents or hot cleaning agents,
as well as cleaning agents containing silicone oil, fluorides or wax, polishes, alkaline cleaning agents and cleaning agents
with abrasive chemical products or high-pressure cleaners. Any methods, means or conditions which can exchange Na
ions from the glass surface are unsuitable for cleaning glass. All abrasive cleaning agents and utensils are also
unsuitable. Please note that too great differences in temperature can lead to tension in the glass, which may damage
the module.
If other cleaning methods or means are used, the anti-reflective coating may be damaged or become dirty down to the
pores, which can lead to visual changes and/or a loss of performance.
