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
Appropriate Size
Neutral Bus
Power Service Disconnect
Power Panel
round Terminal Bar
be
ame 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/da
processing equipment only
*
*
ncoming Three-phase Power
rom service entrance or
eparately derived system
ith appropriate over-current
rotection and suitable ground
