14
Closing the Maintenance Compartment Door
4.8
Installing DC Input Power Cables
4.9
Wiring Description of Y-branch Connectors
• Y-branch connectors can be purchased from Huawei or the manufacturers based on the 
following recommended models: If the rated current of the fuse of the Y-branch connector is 
15 A, the recommended model is 904095944 (Luxshare) or A040959443039 (Comlink); if 
the rated current of the fuse of the Y-branch connector is 20 A, the recommended model is 
904095945 (Luxshare) or A040959453039 (Comlink).
• When connecting cables to recommended Y-branch connectors, ensure that the connectors 
to be paired match each other and are from the same manufacturer. Otherwise, the contact 
resistance of the connectors may exceed the allowed value. In this case, the connectors may 
be heated and oxidized, which may cause faults.
• Ensure that the locking nuts of all connectors are tightened.
• Do not bind more than three fuse enclosures together. Otherwise, the fuses and their 
enclosures may be damaged due to overheating. It is recommended that a clearance of 10 
mm or more be reserved between fuse enclosures. You are advised not to bind the fuse 
enclosures with other heat emitting conductors.
Wiring rules:
1. The PV+ on the string side must be connected to the PV+ on the SUN2000 side, and the PV–
on the string side must be connected to the PV– on the SUN2000 side. 
2. Preferentially and evenly connect the Y-branch connectors to the MPPTs controlled by DC 
SWITCH 1 or DC SWITCH 2.