This article describes the PSU not-supported / unrecognized alarm, which may encounter on EX4300 devices.
Below is the sample example of PSU unsupported alarm seen on EX4300 devices:
root@S1> show chassis alarms no-forwarding 3 alarms currently active Alarm time Class Description 2024-02-16 08:21:14 UTC Major FPC 1 PSU 0 Unrecognized for the platform 2024-02-16 08:17:09 UTC Major FPC 0 PSU 0 Unrecognized for the platform
EX4300 switches except EX4300-48MP and EX4300-48MP-S, switches support 350 W, 715 W, and 1100 W AC power supplies. EX4300-48MP and EX4300-48MP-S switches support 715 W, 1100 W, and 1400 W AC power supplies.
This can be verified in the output of "show chassis hardware" command and below is the sample output.
root@SKOGN1ZEBPUB01> show chassis hardware detail no-forwarding Hardware inventory: Item Version Part number Serial number Description Chassis XXXXXXXXXXXX Virtual Chassis Routing Engine 0 REV 40 650-044936 XXXXXXXXXXXX EX4300-24T Routing Engine 1 REV 40 650-044936 XXXXXXXXXXXX EX4300-24T FPC 0 REV 40 650-044936 XXXXXXXXXXXX EX4300-24T CPU BUILTIN BUILTIN FPC CPU PIC 0 REV 40 BUILTIN BUILTIN 24x 10/100/1000 Base-T PIC 1 REV 40 BUILTIN BUILTIN 4x 40GE QSFP+ Xcvr 0 REV 01 740-038624 XXXXXXXXXXXXXX QSFP+-40G-CU3M Xcvr 1 REV 01 740-038624 XXXXXXXXXXXXXX QSFP+-40G-CU3M Power Supply 0 REV 03 740-074873 XXXXXXXXXXX JPSU-1400W-AC-AFO Power Supply 1 REV 04 740-046873 XXXXXXXXXXX JPSU-350-AC-AFO-A Fan Tray 0 Fan Module, Airflow Out (AFO) Fan Tray 1 Fan Module, Airflow Out (AFO) FPC 1 REV 40 650-044936 XXXXXXXXXXXX EX4300-24T CPU BUILTIN BUILTIN FPC CPU PIC 0 REV 40 BUILTIN BUILTIN 24x 10/100/1000 Base-T PIC 1 REV 40 BUILTIN BUILTIN 4x 40GE QSFP+ Xcvr 0 REV 01 740-038624 XXXXXXXXXXXXXX QSFP+-40G-CU3M Xcvr 1 REV 01 740-038624 XXXXXXXXXXXXXX QSFP+-40G-CU3M Power Supply 0 REV 03 740-074873 XXXXXXXXXXX JPSU-1400W-AC-AFO Power Supply 1 REV 04 740-046873 XXXXXXXXXXX JPSU-350-AC-AFO-A Fan Tray 0 Fan Module, Airflow Out (AFO) Fan Tray 1 Fan Module, Airflow Out (AFO)
The alarm that we are seeing is for PSU0 for both FPCs, this is because the model EX4300-24T supports on 350 W, 715 W, and 1100 W AC power supplies, hence PSU 0 with 1400W is not supported on EX4300-24T.
Under such conditions, replacing the 1400W PSU with any 350 / 715 / 1100 W AC power supplies will clear the chassis alarms.
Please refer below article for more information: https://www.juniper.net/documentation/us/en/hardware/ex4300/topics/topic-map/ex4300-power-system.html#power-supply-ex4300-ac
https://www.juniper.net/documentation/us/en/hardware/ex4300/topics/topic-map/ex4300-power-system.html#power-supply-ex4300-ac