DIRECT CURRENT (DC) POWER DISTRIBUTION SYSTEM (Continued)
When the battery is connected, 24 vdc is supplied
directly to the battery bus. In addition, if the No. 1 dc
bus is not powered, the battery provides 24 vdc to the
switched battery bus through switched battery bus relay
161K10. If the cockpit battery switch is on, 24 vdc is
also provided to the essential dc bus through battery
bus relay 161K1 and essential dc bus relay 161K2.
When power is applied to the No. 1 ac bus the charger
will charge the battery if there are no malfunctions in the
system. It is a constant current charge (10-11 amps)
and will continue until battery is more than 80 percent
charged. At this point, the charger drops to very low
current (0.04 amp). Normal charge (10-11 amps) will
not start again until the battery voltage drops below
approximately 80 percent of rated capacity.
The charger also has provision for low current charging
(1.5 amp) for deeply discharged batteries. A charger
failure will not damage or discharge the battery.
The charger can detect a battery overtemperature
condition and will stop charging. Charging will not start
again until battery cools and charger is manually reset
or power is cycled off and on. The charger will operate
at any frequency between 380 and 440 Hz.