TM 1-1520-238-T-6
9–85
9–7.
SYSTEM DESCRIPTION (cont)
9–7
(m) Overcurrent protection is available when only one T/R is operating (bus tie relay energized). When
the bus tie relay is energized, 28 VDC is routed through the overcurrent (OC) sensing coil. If current flow through
the bus tie relay exceeds 300 30 amps, the overcurrent relay will energize. When the OC relay energizes, the
coil to the bus tie relay is opened, deenergizing the bus tie relay. The shorted bus will be deenergized when the
overcurrent relay is energized.
M69-352
TO HOT RECT 2 INDICATOR ON
AC ESS
BUS 1
T / R 2
DC ESS BUS 2
DC ESS BUS 3
CR4
AND CPG BATT
FROM
AC ESS
BUS 2
FROM
CB2
SENSOR
HEAT
28 VDC
CAUTION / W ARNING PANEL
INDICATORS ON PILOT
TO RECT 1 AND RECT 2
28 VDC
CONTACTOR
DC BUS TIE
SENSOR
HEAT
PANEL
PILOT CAUTION / WARNING
DIODE
ISOLATION
CR2
DIODE
ISOLATION
T / R 1
PANEL
PILOT CAUTION / WARNING
TO HOT RECT 1 INDICATOR ON
CR3
DIODE
ISOLATION
DC ESS BUS 1
CB5
DC EMERG BUS
CR1
DIODE
ISOLATION
OVRD SWITCH
PILOT ELEC PWR PANEL
DC GROUND THROUGH
CB1
CAUTION / WARNING PANEL
INDICATES ON PILOT
TO HOT BAT AND CHARGER
NI-CAD BATTERY
BATTERY
CHARGER
BATTERY
RELAY
Figure 9–76.
DC Electrical Power Generation System Interface Diagram
