SYSTEM COMPONENTS AND PROTECTION DEVICES
Electrical Distribution Systems
Summary
The important information contained in this chapter is summarized below.
System Components and Protection Devices Summary
Single (one-line) diagram - simple and easy to read diagram showing power
supplies, loads, and major components in the distribution system
Commercial or utility power - electric power supplied to the facility
Diesel power - economical/practical source of standby power
Failure-free power - power supplied to vital equipment with automatic switching
so that interruption of power is minimized
Neutral grounding - helps prevent accidents to personnel and damage to property
by fire
Voltage class - high voltage > 15,000 volts, intermediate voltage is 600-15,000
volts, low voltage 600 volts
Protective relays - cause prompt removal of any part of a power system that
suffers a short circuit
Overlapping protective zones - created around each element of the power system
to prevent element failure from interrupting the whole system operation
Breakers - disconnect component from the power system
Fuse - protects component from overcurrent
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