IBM System x3750 M4 Installation And Service Manual page 327

Statement 8
CAUTION:
Never remove the cover on a power supply or any part that has the following
label attached.
Hazardous voltage, current, and energy levels are
present inside any component that has this label
attached. There are no serviceable parts inside these
components. If you suspect a problem with one of these
parts, contact a service technician.
Statement 31:
DANGER
Electrical current from power, telephone, and communication cables
is hazardous.
To avoid a shock hazard:
Do not connect or disconnect any cables or perform installation,
maintenance, or reconfiguration of this product during an electrical storm.
Connect all power cords to a properly wired and grounded power source.
Connect to properly wired power sources any equipment that will be attached to this product.
When possible, use one hand only to connect or disconnect signal cables.
Never turn on any equipment when there is evidence of fire, water, or structural damage.
Disconnect the attached ac power cords, dc power sources, network connections,
telecommunications systems, and serial cables before you open the device covers,
unless you are instructed otherwise in the installation and configuration procedures.
Connect and disconnect cables as described in the following table when
you install, move, or open covers on this product or attached devices.
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.
To remove a 750-watt -48 V to -60 V dc power supply, complete the following
steps:
Procedure
1. Read the safety information and installation guidelines, see "Safety" on page
vii and "Installation guidelines" on page 35.
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 for 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.
Chapter 6. Removing and replacing components
309