CAUTION:
To reduce the risk of electric shock or energy hazards:
vThis equipment must be installed by trained service personnel in a
vConnect the equipment to a reliably grounded safety extra low voltage (SELV) source. An SELV source is a secondary circuit that is designed so that normal and single fault conditions do not cause the voltages to exceed a safe level (60 V direct current).
vThe branch circuit overcurrent protection must be rated 20 A.
vUse 12 American Wire Gauge (AWG) or 2.5 mm2 copper conductor only, not exceeding 4.5 meters in length.
vIncorporate a readily available approved and rated disconnect device in the field wiring.
CAUTION:
Disconnect the dc power jumper cord from the dc connector on the dc power supply and fan unit before replacing the dc power supply and fan unit.
The dc power supply and fan unit is a component that includes both a
Each dc power supply and fan unit has a
v
v
vOverheated power supply
If any of these conditions occurs, one or both power supplies will shut down. If the power remains off after the condition that causes it to go off, make sure that the environment is optimal (no overheating has occurred, all electrical outlets are working, and so on). For more information, see “Restoring power after an unexpected shutdown” on page 137.
The storage subsystem cooling system consists of two fans in each of the two dc power supply and fan unit CRUs. The dc power supplies circulate air from the front to the back of the unit.
If both dc power supplies fail, or if the dc power supplies cannot maintain an internal temperature below 68° C (154° F), the dc power supplies in the unit will automatically shut down (an
170IBM System Storage DS4700 Express Storage Subsystem: Installation, User’s and Maintenance Guide
