Appendix B. Electrical Circuit And Wiring Information; Fault Protection Requirements; Grounding Considerations; Circuit Wiring Diagrams - NEC Express5800/320Ma Planning Manual

For electrical circuit and wiring information that you need to provide to the contractor
and/or facilities personnel responsible for wiring the power at the system installation
site, see:
•
"Fault Protection Requirements" on page B-1
•
"Grounding Considerations" on page B-1
•
"Circuit Wiring Diagrams" on page B-3
•
"Electrical Power Connectors" on page B-9

Fault Protection Requirements

Each enclosure in Express5800/320Ma 3.2 GHz, 3.6 GHz, or Dual-Core systems
contains internal fault/overload current protection. However, the system relies on the
power distribution system at your site for protection against potential faults in the power
cords and the wiring in the system base.
•
If you are using a pair of PDUs in the cabinet, use 30A or less circuit breakers in
each power distribution branch that feeds the PDUs.
•
To connect a single system to power, use 20A or less circuit breakers in each power
distribution branch that feeds the systems.

Grounding Considerations

The system obtains an earth reference ground through the power cords attached to the
system. Similarly, each peripheral device connected to the system obtains ground
through its power cord. For each peripheral device, you must ensure that a
high-integrity safety-ground conductor is installed as part of the wiring system (in
accordance with U.S. national electric code NFPA 70 or the equivalent). The
international safety standard (EN60950) for electronic data processing (EDP)
equipment also requires a ground conductor, but calls it a protective earth (PE) ground.
Depending upon local conditions, ground potentials may differ between the system
base and any peripheral devices connected to the system base. All grounds in the
system must return to the same reference point in the power distribution system, as
close as possible to zero (0) volt potential relative to earth reference ground. Earth
Electrical Circuit and Wiring Information
Electrical Circuit and Wiring Information
Appendix B
B-1
B-