Power supply

The power supplies are the main source of power for your storage unit. They also contain the fans that circulate the air to keep your storage unit cool.

The power supplies are located on the right and left sides of the rear of the enclosure.

The redundant dual ac/dc power supplies in each storage unit provide dc power to the enclosure resources. The power supplies perform the conversion from ac power input to dc power output that is required for the storage unit resources and functions. Each individual power supply has the capacity to independently power the entire server or expansion enclosure.

The ac power cord connects the power supplies to an external power source. This cord supplies ac power from the wall outlet to the power supply.

Note: If possible, plug each of the power supplies into separate ac power sources.

Each power supply contains a fan that performs cooling management functions. There is a redundant pair of enclosure cooling system fans that are imbedded within each power supply. The fans within each power supply are arranged so that no single fan failure deprives the system of enough airflow to cool the entire enclosure, provided that the enclosure airflow circulation boundaries remain intact.

The power supplies include the ac power present, dc power present, and service/fault LED indicators. Figure 1 shows the LED indicators that are located on the power supply. The indicators are explained in Table 1.

Figure 1. LED indicators on the power supply

Table 1. Indicator descriptions for the power supply
Indicator name (color)	Purpose	State descriptions
ac power present (green)	Indicates the status of the ac line cord power to the power supply.	Solid: ac power is available to the power supply. Off: ac power is not available to the power supply.
dc power present (green)	Indicates the status of the dc power being output from the power supply to the storage unit.	Solid: The +12 V dc, +5 V dc and +3.3 V dc (standby) power outputs are available. Flashing: dc standby (+3.3 V dc) power output is available. +12 V and +5 V power outputs are not available. Off: dc power output is not available.
Service/fault (amber)	Indicates fault conditions that have been detected within the power supply.	Solid: A fault condition has been detected and this resource requires service. Flashing: The resource has been identified by system management. Off: No known faults exist. This is the default state for this indicator.