The -48 V power supply cannot be used when the Huawei MA5616 uses the PAIB power board.
PAIB is an AC input power board and uses AC power supply by default. Its DC terminal is connected to -48 V battery. PAIB is installed with a relay for protecting the battery and the relay turns on the circuit to the -48 V battery for power supply only when the mains supply fails. In this case, if PAIB of the MA5616 requires DC power supply, mains supply must be connected and then powered off. If the mains cannot be connected, PAIB must be replaced with PDIA