IBM System Storage DCS3700 Installation, User's, And Maintenance Manual page 16

Statement 29:
CAUTION:
This equipment is designed to permit the connection of the earthed conductor of the dc supply circuit
to the earthing conductor at the equipment.
This equipment is designed to permit the connection of the earthed conductor of the dc supply circuit
to the earthing conductor at the equipment. If this connection is made, all of the following conditions
must be met:
v This equipment shall be connected directly to the dc supply system earthing electrode conductor or
to a bonding jumper from an earthing terminal bar or bus to which the dc supply system earthing
electrode conductor is connected.
v This equipment shall be located in the same immediate area (such as, adjacent cabinets) as any
other equipment that has a connection between the earthed conductor of the same dc supply circuit
and the earthing conductor, and also the point of earthing of the dc system. The dc system shall not
be earthed elsewhere.
v The dc supply source shall be located within the same premises as this equipment.
v Switching or disconnecting devices shall not be in the earthed circuit conductor between the dc
source and the point of connection of the earthing electrode conductor.
Statement 30:
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.
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IBM System Storage DCS3700: Installation, User, and Maintenance Guide