UFC 3-560-01
6 December 2006
Including change 1, 7 December 2006
13-4.3.2.4 Each activity should evaluate the comparisons as to their effect on workers
safety and provide SOP's as necessary to assure safe working conditions.
13-4.4
Ship's Electrical Power Input Safety. Ship's electrical input cables must
provide an ungrounded correctly phased, correctly-cable-oriented system providing an
adequate number of power cables to serve the ship's load.
13-4.4.1 The ship's hull serves as the ground for the ship's electrical service. A
ground connection between the shore ground and the ship's ground can result in
damaging circulating currents.
13-4.4.2 Improper matching of phase rotation will result in the ship's motors operating
in the wrong direction. Connecting two or more power cables to a ship requires that all
the same phase cables be connected together.
13-4.4.3 The number of power cables should meet the ship's electrical officer's request
that is based upon the ship's activity in port. When more than one feeder cable is
required, all cables will be of the same length and size (within plus or minus 10 percent)
to minimize unequal load distribution.
13-4.5
Parallel Operation.
WARNING
Parallel operation of the ship and shore systems can be performed only in
accordance with the following precautions.
13-4.5.1 Parallel operation of the ship generators and the shore power system is
prohibited except for short periods of time to allow for load transfer to or from shore
power. Transfer time should not exceed 10 seconds.
13-4.5.2 Paralleling shore transformers through the ship's electrical bus without prior
activity approval is a violation of safety practices and can result in circulating currents,
overheated cables, unbalanced loads, and excessive shore circuit current which could
damage property and result in personal injury.
13-5
SUPPORTING SHORE-TO-SHIP SAFETY REQUIREMENTS. The previous
sections cover the general electrical safety requirements for operating and maintaining
shore electrical distribution systems. The unique power cable connection/disconnection
operations for shore-to ship electrical power service requires specialized training and
appropriate SOPs.
13-5.1
Specialized Shore-to-Ship System Training. Qualifying for this work
requires training that addresses the operation, maintenance, and testing of the power
cable/connector assemblies; the ability to connect cable extensions; and the
understanding of cable phasing and paralleling checking methods. Workers should also
13-15
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