IBM System x3550 M4 Installation And User Manual page 105

v The server comes with one hot-swap 12-volt output power supply that connects
to power supply bay 1. The input voltage is -48 V dc or -60 V dc auto-sensing.
v Before you install a dc power supply in the server, you must remove all ac power
supplies. Do not use both ac and dc power supplies in the same server. Install
up to two dc power supplies or up to two ac power supplies, but not a
combination.
v Power supply 1 is the default/primary power supply. If power supply 1 fails, you
must replace the power supply with the same wattage immediately.
v You can order an optional power supply for redundancy.
v These power supplies are designed for parallel operation. In the event of a
power-supply failure, the redundant power supply continues to power the system.
The server supports a maximum of two power supplies.
v It is the customer's responsibility to supply the necessary power cable.
To reduce the risk of electric shock or energy hazards:
– Use a circuit breaker that is rated at 25 amps.
2
– Use 2.5 mm (12 AWG) at 90° C copper wire.
– Torque the wiring-terminal screws to 0.50 ~ 0.60 newton-meters (4.43 ~
5.31 inch-pounds).
For more information, see Statement 34 on page 91.
v If the power source requires ring terminals, you must use a crimping tool to
install the ring terminals to the power cord wires. The ring terminals must be UL
approved and must accommodate the wire that is described in the
above-mentioned note .
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 31:
Chapter 2. Installing optional devices
89