5-13
Understanding and Maintaining Components
Power Supply Units
The DuraStor power system consists of two 350-watt hot-
swappable power supply units (PSUs), each with independent AC
power and cooling fans. This system provides the storage
subsystem with N+1 redundant power. Each PSU has auto-
switching circuitry for use with either 110V or 220V AC systems. A
PSU is shown in
.
Figure 5-10 Power Supply Unit (PSU)
Each PSU has a power switch and a Power On LED, a power cord
connector (with a security bale that fits over the power cord to
prevent accidental disconnections), and an independent AC power
cord. (The power switches are identified with a 1 for
ON
and a 0 for
OFF
.
When you turn on a PSU, its own Power-on LED and the Power
Supply LED on the front bezel light up, and the storage subsystem
performs a power-on self-test (POST).
If a PSU fails, the Power Supply LED changes from solid green to
solid amber and the audible alarm sounds. On the failed PSU, the
green Power On LED goes out and the amber Fault LED lights up.
If only one power supply is operational, the front bezel Power LED
is amber.
Power
switch
LEDs
Power cord connector
and security bale
DuraStor IUG - Online.book Page 13 Friday, July 19, 2002 3:06 PM