Lenovo System x3550 M5 Installation And Service Manual page 220

To Connect:
1. Turn OFF all power sources and equipment that is to
be attached to this product.
2. Attach signal cables to the product.
3. Attach power cords to the product.
• For ac systems, use appliance inlets.
• For dc systems, ensure correct polarity of -48 V dc
connections: RTN is + and -48 V dc is -. Earth
ground should use a two-hole lug for safety.
4. Attach signal cables to other devices.
5. Connect power cords to their sources.
6. Turn ON all the power sources.
CAUTION:
This product does not provide a power-control button. Turning off blades or removing power modules
and I/O modules does not turn off electrical current to the product. The product also might have more
than one power cord. To remove all electrical current from the product, make sure that all power
cords are disconnected from the power source.
CAUTION:
To reduce the risk of electric shock or energy hazards:
• 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.
• Connect the equipment to a properly grounded safety extra low voltage (SELV) source. A 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).
• Incorporate a readily available approved and rated disconnect device in the field wiring.
• See the specifications in the product documentation for the required circuit-breaker rating for
branch circuit overcurrent protection.
• Use copper wire conductors only. See the specifications in the product documentation for the
required wire size.
• See the specifications in the product documentation for the required torque values for the
wiring-terminal screws.
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Lenovo System x3550 M5 Installation and Service Guide
To Disconnect:
1. Turn OFF all power sources and equipment that is to
be attached to this product.
• For ac systems, remove all power cords from the
chassis power receptacles or interrupt power at
the ac power distribution unit.
• For dc systems, disconnect dc power sources
at the breaker panel or by turning off the power
source. Then, remove the dc cables.
2. Remove the signal cables from the connectors.
3. Remove all cables from the devices.