Replacing a power supply unit

You can replace a power supply unit (PSU) as a hot-swappable server component. The server can operate on a single PSU if necessary, making it possible to replace a failed PSU without shutting down the server. If a PSU fails, it should be replaced as quickly as possible, because operating on a single PSU means that there is no redundancy in that area, increasing the risk of an interruption in service to clients.

LED indicators on each PSU indicate the PSU status.

Figure. PSU locations on NAS Platform Series 4000 rear panel

CAUTION:

You cannot use the power supply from an HNAS 4060, 4080, and 4100 server in an HNAS 4040. The HNAS 4040 server uses the same PSU as the HNAS 3080 and 3090 servers.

Note: Although the following figure shows the HNAS 4060, 4080, and 4100 rear panel, the PSU locations are the same on the HNAS 4040 model.

Item	Description
1	PSU 1
2	PSU 2

Figure. PSU components

Item	Description
1	PSU fan
2	Power plug
3	Retaining latch
4	Handle
5	DC power LED
6	Malfunction or failure LED
7	AC power LED

1. Remove the power cord from the PSU.
2. Move the retaining latch to the right (you may hear a slight click if the PSU moves when the latch disengages).
3. Using the handle on the PSU, pull the PSU out from the back of the server until you can completely remove the PSU from the chassis.
4. Insert the replacement PSU. The retention latch should click into position all the way to the left when the PSU is fully inserted.
   If the PSU that is not being replaced is receiving mains power when the replacement PSU is fitted, the fan on the replacement PSU becomes active.
5. Connect the power cord to the back of the PSU.
   The PSU should start as soon as the power connection is made. If the PSU does not start immediately, make sure the mains power circuit is live and that the other end of the power cable is connected to a live outlet.