TM 55-1930-209-14&P-9-1
g.
Turn SYNCHROSCOPE off by turning INCOMING GENERATOR switch to OFF (Figure 2-14).
CAUTION
Reverse power can occur when two generators are running In parallel. A generator may
not accept a load, usually because Its unloaded running speed Is less than the other
generator (called speed droop). The other generator will motorize, or reverse power, the
drooping generator. This situation creates an undue load on the powering generator and
may damage the reverse powered generator.
h.
Transfer load from offgoing generator to oncoming generator by using AUTOMATIC VOLTAGE CONTROL
RHEOSTAT controls (Figure 2-11). Simultaneously increase load on oncoming generator by turning control
clockwise and decrease load of offgoing generator by turning control counter clockwise.
i.
Once offgoing generator load has been reduced to a minimum, open that generator’s circuit breaker connecting
it to switchboard bus.
2-14.1
Correcting reverse power situation. If reverse power situation develops, reverse power indicator light for that
generator comes on and a safety relay immediately shuts down that generator.
a.
Immediately go through shutdown procedures, paragraph 2-17, for generator set that has been shut down by
safety relay.
b.
Allow loaded generator about 10 seconds to stabilize.
c.
Adjust generator voltage to 450 V, if necessary, by using AUTOMATIC VOLTAGE CONTROL RHEOSTAT
control (Figure 2-11).
d.
Adjust generator frequency to 60 Hz, if necessary, by using GOVERNOR SPEED CONTROL switch.
e.
Start the shutdown generator by following procedures in paragraphs 2-11 and 2-13.
f.
Parallel generators according to paragraph 2-14 and try load transfer again.
2-15.
Operating procedures using shore power. Shore power, if available from an onshore power source or another
vessel, is connected to shore power receptacle on aft weather deck bulkhead port side.
a.
Verify that shore power is 440 Vac, 60 Hz, 3 ph. If power does not match this requirement, switchboard circuit
breaker P4 (Figure 2-15), connecting shore power to switchboard bus, will not close.
b.
Verify that all loading circuit breakers (Figure 2-12 or 2-13) on switchboard are open (OFF). Electrically, a dead
ship condition must exist prior to engaging shore power circuit breaker.
c.
Verify that switchboard circuit breakers for generators (P1 for SSG 1, P2 for SSG 2, and P3 for SAG) (Figure 2-
14) are open (OFF).
d.
On switchboard panel, dose (ON) circuit breaker P4 (Figure 2-15).
e.
Apply load as required by dosing circuit breakers on switchboard panel.
2-16.
Operating other electrical panels and controls. Electrical panels and controls, other than those on the
switchboard, are self-explanatory and labels show their function. Instructions on when to use these controls are included in
chapters covering the affected systems.
CAUTION
Circuit breakers on electrical panels should not be used as switches. All electrical
devices onboard have switches, control boxes, and or starters that provide normal
control. Circuit breakers should be used only when safety requirements dictate that a
circuit be totally Inactive or when that system Is being placed In storage.
2-27
