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|  MIL-G-24477(SHIPS)
In addition, the set shall not leak oil under trim angles up to 30 degrees. This is not
an operating condition. Degrees indicated are measured from the vertical to either side
for list and roll, and from the horizontal fore and aft plane, up or down, for trim and
pitch. The conditions of permanent list and roll or trim and pitch shall not be considered
additive. The resultant angle of inclination from the following combinations shall be met.
List
and
trim
(a)
(b)
List
and
pitch
Roll
and
trim
(c)
(d)
Roll
and
pitch
3.1.9 The contractor shall provide the following items:
(a) A low engine speed shutdown control for snorkel operation which shall include
a shutdown device, switch, and governor solenoid operating from a 115 volt,
60 Hertz, a.c. source. The device shall be adjustable between approximately
50 percent to 90 percent of rated speed, and shall actuate the switch when
the speed falls to a minimum of 80 percent of rated speed. The switch shall
reenergize the governor solenoid which in turn shall shut the engine down.
The governor solenoid shall be provided with a manual over-ride for emergency
stops and for set starting with the solenoid deenergized. The low speed
switch shall be of the double pole, single throw type, 3 to 5 pounds per
square inch (p.s.i.) range, set to open on decrease of lube oil pressure.
An identical low speed switch shall also be installed to trip the generator
circuit breaker when the speed falls to a minimum of 80 percent of rated
speed. The settings of these switches shall be such that the generator
breaker switch operates first.
(b) An overspeed trip actuated switch for tripping the generator circuit breaker.
(c) A 1/2 inch connection in the blower inlet and discharge for installation of
a differential temperature thermometer.
(d) A 1/2 inch connection in the engine crankcase for manometer connection.
(e) A governor synchronizing motor, single phase, 115 volt a.c., readily
reversible.
3.1.10 Shock. The diesel gnerator set and associated accessories shall meet the shock
requirements of the appendix.
3.1.11 Speed characteristics. The speed governing system shall be of the speed sensing
mechanical-hydraulic speed characteristics as defined by MIL-STD-178 as follows:
3.6 to 4.0
(a) Steady state speed regulation limits (percent) . . . . . . .
(b) Maximum steady-state governing speed band
(percent plus or minus of rated speed) . . . . . . . . . .
0.33
(c) Minimum range of speed regulation changer
0.0 to 5.0
(percent of rated speed) . . . . . . . . . . . . . . . . .
(d) Minimum range of speed changer (percent of rated speed) . .
90 to 105
(e) Maximum permissible momentary underspeed and overspeed
(percent of rated speed) upon application or removal
of 100 percent load . . . . . . . . . . . . . . . . . . . .
7.0
(f) Maximum permissible recovery time in seconds following
underspeed and overspeed . . . . . . . . . . . . . . . . .
5
Prescribed speed band for determination of recovery time
(g)
(percent plus and minus of rated speed) . . . . . . . . . .
0.5
3.1.12 Short circuit. The generator set shall be capable of withstanding without
damage to any parts, the torques associated with a 3 phase fully asymmetrical short circuit
at the switchboard assuming 25 feet of interconnecting cables from the generator terminals
to the switchboard.
(Also see 3.3.6.)
3.1.13 Vibration resistance. The diesel generator set shall meet the vibration re-
quirements of types I and III in accordance with MIL-STD-167.
3.1.14 The generator set shall be provided with an air starting system as specified in
The generator set shall start, continue operating and be capable of providing
3.2.5.7.
rated voltage at the generator terminal within 10 seconds after the starting mechanism is
set in operation without the use of cold starting aids. The set shall be capable of pro-
viding full output power immediately after completion of the start.
7
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