6.
Bypass diodes and current
protection
6.1 Bypass diodes
In a system with two or more Modules connected in series, if part of a Module is shaded while the other
part is exposed to the sun, a very high reverse current will go through the cells which have been partly or
entirely covered and it will cause overheat on the cells, which may damage the Module. Using bypass
diodes can protect modules from this kind of risk.
Only professionals are allowed to install the bypass diodes. Open the junction box cover and install the
same type diodes in the appropriate holes in the module.
6.2 Current protection
Always install a fuse or circuit breaker for the module that matches its maximum fuse current and
system voltage in accordance with local regulations. To ensure the protection of the fuse, refer to the
fuse range recommended on the module nameplate, and refer to the local power installation safety
manual
When the modules are installed in parallel, each piece of module or a string of cells must have a fuse
that meets the maximum fuse current specified in the power specification.
The nominal rating of all electrical components shall not be less than the nominal rating of the system
and shall not exceed the maximum system voltage indicated on the module nameplate。
7. Maintenance
7.1 Visual and electrical inspection
The modules in a PV array should be regularly checked for damage. Factors such as glass breakage,
cable breakage, and junction box damage may lead to function and safety problems
It is recommended to perform a preventive inspection every six months without changing the
components of the module. If electrical or mechanical properties are required for inspection or
maintenance, qualified professionals should be advised to avoid any electric shock or loss of life
Inspect for loose or corroded electrical interfaces, loose connections between supports and components,
connections between cables, connectors, and grounding.
Replacement modules must be of same type. Do NOT touch live parts of cables and
connectors.
Use appropriate safety equipment (insulated tools, insulating gloves, etc.) when handling modules.
Trim any vegetation which may shade the solar array, thus impacting performance.
7.2 Cleaning
The amount of electricity generated by a solar module is proportional to the amount of light falling on
it. A module with shaded cells will produce less energy and therefore it is important to keep modules
clean. Appropriate maintenance measures shall be taken to keep the assembly free of snow, guano,
seeds, pollen, leaves, branches, dust and stains, etc.
In most conditions, the normal rainwater can keep the module glass clean. Clean the glass surfaces
with wet soft sponge or cloth if necessary. Use mild non-abrasive cleaning agent to remove stubborn
dirt. If the module installation Angle with the ground is 0 °, it required relatively frequent cleaning
frequency. In general, if installation Angle is 15 °, the module’s self cleaning ability is better than 0 ° .
When cleaning PV modules, do NOT step on the modules; do NOT spay water on the backside of the
module or the cables; do NOT clean the backside of the modules; keep the connectors clean and dry;
prevent fire and electrical shock from occurring; do NOT use as steam cleaner.
Modules can work effectively without cleaning, but removing dust from the glass surface can increase
output power. Use a wet sponge or cloth to clean the surface of the glass. Wear rubber
