Sun Microsystems StorageTek 96257 - Manual (Page 49)

96257 Sun Confidential: Internal Only 4-49
Revision A
Site Evaluation – Internal Considerations
Site Power Distribution Systems
The following elements of the site power distribution system should be evaluated when
planning an installation of VSM5 system equipment.
System Design
A properly installed power distribution system is required to ensure safe operation of
VSM5 system equipment. Power should be supplied from a feeder separate from one
used for lighting, air conditioning, and other electrical systems.
A typical input power configuration, shown in Figure 4-1 , is either a five-wire high-voltage
or a four-wire low-voltage type, with three-phase service coming from a service entrance
or separately derived source, and with overcurrent protection and suitable grounding. A
three-phase, five-wire distribution system provides the greatest configuration flexibility,
since it allows power to be provided to both three-phase and single-phase equipment.
Figure 4-1. Site Electrical Power Distribution System
Circuit Breakers of
Appropriate Size
Neutral Bus
Remotely Operated
Power Service Disconnect Computer Room
Power Panel
Ground Terminal Bar
b e
Same size as neutral
( onded to nclosure)
Neutral
Ground
Service Entrance
Ground or Suitable
Building Ground
Note: Bounding of neutral and ground at other
points is Illegal.
Only valid at
service entrance
or separately
derived system
(transformer)
Insulated Green Wire Ground
Phase Wires and Neutral
Ledgend:
Customer Supplied
Receptacles/Connectors-
in Accordance with
Local Codes 208/240V
3-Phase
(5-wire)
208/240V
3-Phase
(4-wire)
208/240V
Single
Phase
120V
Single
Phase
Branch Circuits
For loads requiring a
neutral attach computer/data
processing equipment only
A502_046
*
*
Incoming Three-phase Power
from service entrance or
separately derived system
with appropriate over-current
protection and suitable ground