TM 55-1930-209-14&P-1
3-20.2 The Perkins 4.236M engine is a 236-cubic inch inline, four cylinder, four-stroke diesel specifically built for use in a
maritime environment. It has direct injection, with a 16:1 compression ratio and is rated at 72 hp at about 2500 rpm. The
engine has a heat exchanger using seawater to cool both engine coolant and engine oil and a 24 V electric starter. The
battery pack on the engine is charged by a battery charger built into the switchboard in the ROWPU space.
3-20.3 The Newage Stamford SC144E generator is a brushless, revolving field machine. It is based on a fabricated
frame and cast iron end brackets with a large sheet metal terminal box mounted on the nondrive end. The stator/rotor is
made from low loss electrical grade sheet steel laminations with special building techniques to provide an extremely rigid
core to withstand vibration and load impulses. A high-grade, precision-machined shaft carries the rotor assembly. For a
more detailed technical description, refer to manufacturers' manuals listed in TM 55-1930-209-14 & P-9.
3-21 Capabilities. This auxiliary generator set provides electrical power necessary for normal occupancy of the barge
when major ROWPU systems are NOT operating. It will provide continuous power under these conditions. For load
transfer purposes only, it may be operated, for a very short time, in parallel with either of the two SSG's.
3-22 Special limitations. This generator set cannot be operated in parallel with power from the shore power receptacle.
It cannot be used to provide power for any major systems onboard. It must be used only to provide power for normal non-
operating occupancy and housekeeping equipment.
3-23 Performance characteristics. The auxiliary generator's voltage regulation is maintained within the limits of ±2
percent from no load to a full load. This includes cold to hot variations at any power factor between 0.8 lagging and unity
and inclusive of a speed variation of 4.5 percent. Total distortion of the voltage waveform, with open circuit between
phases or between phases and neutral, is on the order of 2 percent. On a 3-phase, balanced, harmonic-free load, total
distortion is on the order of 3.5 percent. Electrical output characteristics at an 0.8 power factor are listed below:
kW
20
kVA
25
Voltage
440 Vac
Current
32
Phase
3
Hertz
60
3-24 Description of operation. Normally, this generator set is started as soon as the barge is activated. When major
ROWPU systems are not operating, SAG provides power for normal housekeeping functions such as lighting, heating, air
conditioning, ventilation, operation of dayroom and workshop equipment, and initial startup of chlorination system. This
auxiliary generator set cannot provide sufficient power to operate any of the major ROWPU systems. One of the two
SSG's must be online to provide sufficient power for operating any major ROWPU system. When one of the SSG's is
online, the 20 kW set is normally shut down.
3-24.1 This generator, like the two SSG's, is normally started and operated from a control panel on the switchboard in the
ROWPU space.
3-24.2 Like the two SSG's, this generator can operate in parallel with either of the two SSG's for load transfer.
3-42
