Huawei PTN Series Quick Installation Manual page 11

When the air breaker of the PDU is off, insert the power connector to the power interface on the chassis.
After inserting the power connector, tighten the latches on both sides to prevent the connector from disconnected
Among the four power cables, the upper two form one pair and the lower two the other pair. Either pair of
power cables corresponds to a power supply. Therefore, these power cables must be properly interconnected
with the PDU.
4
Installing the E1 Cable
When installing and routing cables, refer to the
service network cable, and fiber at the opposite end.
The PIU boards are of 1+1 hot backup.
engineering document
8
on site to install and connect the E1 cable,