A S S I G N M E N T
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Textbook Assignment: “AC Power Distribution System,” chapter 3, pages 3-1 through
3-18; “Ship’s Input Systems,” chapter 4, pages 4-1 through 4-9;
It Information Transfer Systems, “chapter 5, pages 5–1 through
5-16.
Learning Objective: Identify the fundamentals
of the ship’s service power distribution
systems.
2-1.
Which of the following systems
comprises the shipboard power
distribution system?
1.
The casualty power system only
2.
The emergency power system only
3.
The ship’s service system only
4.
All of the above
2-2.
What is the function of the
switchboard bus ties?
1. To permit switchboards to be
cross connected and to allow
paralleling of generators
2. To allow power distribution
directly from the generator to
the load
3.
To allow the generators to
operate in series
4.
To feed power to the dc
generator
2–3.
On small ships, centrally locating
switchboards (with respect to the
load) and feeding them directly
from the generators have which of
the following advantages?
1.
It simplifies the installation
2.
It reduces size and weight
requirements
3.
It reduces equipment
requirements
4.
Each of the above
2-4.
Circuit information plates are
located on which of the following
locations?
1.
The bulkhead near the fuse
boxes
2. The distribution panels and bus
transfer equipment
3.
The electric cables
4.
All equipment controllers
2-5.
Why is the phase sequence important
to the power distribution system
aboard ship?
1.
An improper phase will cause
voltage fluctuations
2.
The phase sequence determines
the amount of current available
3.
The phase sequence determines
the direction of rotation of
three-phase motors
4.
Distribution panel bus bars are
label alphabetically from top
to bottom
2-6.
What service is provided by bus
transfer equipment?
1.
It provides two sources of
power to vital ship’s equipment
2.
It provides short-circuit
protection to the ship’s
service generators
3.
It provides overload protection
to ship’s circuit breakers
4.
It provides protection from
paralleling two switchboards
that are out of phase
2-7.
If NORMAL power were to fail
supplying the HF transmitter,
ALTERNATE power would be restored
by the use of which of the
following components?
1. Manual bus transfer (MBT) only
2. Automatic bus transfer (ABT)
only
3.
Either 1 or 2 above
4.
Communications switchboard
2-8.
Aboard ships, switchgear groups are
physically separated as much as
practical to achieve what
objective?
1.
Easy access for maintenance
2.
Reduce accidental loss of power
3. Afford greater protection from
battle damage
4.
Prevent unnecessary cost and
weight during ship’s
construction
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