6.2 Cables and Wiring
P
V Modul
e's junction boxes with the IP67 protective level, can provide the safety protection for cable and wiring connection, also
for contact protection of non-insulating electric parts. Each module has two individual wires connecting the junction box, one is
negative pole and the other is positive pole. Two modules can be in series connection by inserting the positive pole at one end of
wire of one module into the negative pole of the adjoining module.
6.3 Connector
Please keep connectors clean and dry. Make sure connector caps are fastened before connection. Do not connect
connectors under improper conditions of damp, dirty or other exceptional situations. Avoid connectors from direct sun
light and water immersion or falling onto ground or roof.
Incorrect connection may lead to electric arc and electric shock. Please make sure that all electric connection is reliable.
Make sure all connectors are fully locked.
Only connectors as the compatible model from same vendor can be mated together. Any doubt, please consult LONGi
customer service personnel).
6.4 Bypass diode
LONGi solar module junction box contains bypass diode which is in parallel connection with the cell string. If hot spot
occurred, the diode will come into operation to stop the main current from flowing through the hot spot cells in order to
prevent module over-heated and performance loss. Notice, bypass diode is not the overcurrent protection device.
If the diode is definite or suspected to be defective, the installer or system maintenance supplier shall contact LONGi.
Please do not try to open the module junction box on your own.
6.5 PID Protection and Inverter Compatibility
①
PV modules may appear Potential Induced Degradation (PID) under high humidity, high temperature and high
voltage condition. Modules may appear Potential Induced Degradation (PID) under the conditions below:
◇
PV modules install under hot and humid weather condition.
◇
PV modules installation site is under long-term humid environment such as water floating application.
②
To reduce the risk of PID, on the modules DC connection site, it is recommended to connect the negative to ground.
The PID protection measures on system level are recommended as follow
◇
For isolated PV inverter, the negative of the PV modules DC connection side can be directly grounded.
◇
For non-isolated PV inverter, isolated transformer is needed to be equipped before applying virtual grounding
method for inverter.
According to local fire protection, building and electrical regulation, apply proper cable and connector; ensure the electrical and
mechanical property of the cables (the cables should be put in a catheter with anti-UV aging properties, and if exposed to air, the
cable itself should have anti-UV aging capability).
The installer can only use single-wire cable, ≥ 4mm2 (12 AWG), 90
℃
, with proper insulation capability to withstand the
maximum open circuit voltage (such as EN50618 approval). Need to select appropriate wire specifications to reduce voltage
drop.
LONGi requires that all wiring and electrical connections comply with the appropriate National Electrical Codes.
When cables are fixed on the bracket, avoid mechanical damaging cables or modules. Do not press cables by force. Adopt UV
resistant cable ties and clamps to fix cables on the bracket. Though cables are UV resistant and water proof, it is still necessary
to prevent cables from direct sun light and water immersion.
The minimum allowed bending radius of cables should be 43mm. (1.69 inch)
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