CAUTION:
To reduce the risk of electric shock or energy hazards:
v
This equipment must be installed by trained service personnel in a
restricted-access location, as defined by the NEC and IEC 60950-1, First
Edition, The Standard for Safety of Information Technology Equipment.
v
Connect 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).
v
The branch circuit overcurrent protection must be rated 20 A.
v
Use 12 American Wire Gauge (AWG) or 2.5 mm2 copper conductor only, not
exceeding 4.5 meters in length.
v
Incorporate a readily available approved and rated disconnect device in the
field wiring.
CAUTION:
This unit has more than one power source. To remove all power from the unit,
all dc MAINS must be disconnected.
CAUTION:
There is current to the power supply and fan units even though the power
supply switch is in the OFF position. Use a disconnect device to shut power
off before unplugging the dc power jumper cable from the dc power supply
connectors.
There are two ways to cable the dc power supply and fan units:
v
Single-level redundant dc cabling
v
Dual-level redundant dc cabling
Single-level redundant dc cabling
In a single-level redundant dc cabling scheme, the DS4700 Express NEBS models
are connected to the dc power source using the two dc power cords that are
shipped. Only one dc power connector in each of the dc power supply and fan units
is connected to a dc power source. The other dc power connector in each dc power
supply and fan unit is left open. The dc power connectors A1 (
5
) are connected to
the left dc power source (
1
) while dc power connectors B1 (
6
) are connected to
the right dc power source (
2
). This cabling scheme protects against any single
failure such as failed dc source, dc power supply, or dc cable. Figure 92 on page
113 illustrates single-level redundant cabling.
112
IBM System Storage DS4700 Express Storage Subsystem: Installation, User’s and Maintenance Guide
Summary of Contents for DS4700 EXPRESS
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