TM 55-1930-209-14&P-1
3-6 Description of operation. Normal electrical power is generated onboard by one of three diesel-powered generator
sets. Two of these are rated at 155 kW (designated as SSG1 and SSG2 sets), and one is rated at 20 kW (designated as
the SAG set). Except for a few minutes when transferring power loads from one generator to another, only one of these
three generators is providing power (termed "online") at any moment. These generator sets are normally operated and
controlled from the master switchboard in the ROWPU space. For maintenance and servicing, they can be locally
operated and controlled at the generator set location.
Either 155 kW SSG set supplies electrical power to the switchboard power distribution center. Power flow is then
distributed from the switchboard directly to ROWPU operating equipment and to subordinate distribution panels for the
auxiliary systems used in barge support. Electrical power generated by the 20 kW SAG set also flows through the
switchboard power distribution center, but power from the SAG is distributed only to crew support auxiliary systems such
as communications, dayroom equipment, workshop equipment, and interior lighting. When electrical power is supplied
from either a shore-based facility or from another vessel, the power is received through the shore power receptacle
located on the weather deck portside, from there it flows to the switchboard distribution center. Table 3-2 lists power
distribution from normal electrical power supply sources.
Table 3-1. Electrical Power System Major Components
Component
Quantity/Function
Location
Switchboard
1 - Controls and distributes
ROWPU space port bulkhead aft
electrical power
Shore power receptacle
1 - Receives power from outside
Stem weatherdeck portside
source
SSG
2 - Provides electrical power
Voids 4 port & starboard
SAG
1 - Provides electrical power
Void 4 starboard
Power panel 1
1 - Distributes 440 Vac power
ROWPU space port bulkhead forward
near door to weatherdeck
Power panel 2
1 - Distributes 440 Vac power
ROWPU space starboard
bulkhead forward of sliding door
Power panel 3
1 - Distributes 220 Vac power
ROWPU space forward bulkhead
Power panel 4 (Barge 1)
1 - Distributes 440 Vac power
ROWPU space starboard
bulkhead
Deck lighting panel
1 - Controls electrical power
ROWPU space starboard
for deck lights
bulkhead
Void lighting panel
1 - Controls electrical power
ROWPU space starboard
for void lights
bulkhead near dayroom door
Receptacle panel
1 - Controls electrical power
Workshop aft bulkhead
to receptacles
Ground detector panel
1 - Indicates ground in 120 Vac
ROWPU space forward
power system
bulkhead
Emergency shutdown
1 - Shuts down electric-powered
See paragraph 3-7.9
equipment or total electric power
3-12
