Learjet 20 Series Pilot Training Manual page 30

Battery Overheat Warning—
Nicad Batteries Only
There are two red battery overheat lights
(Appendix B), one labeled "BAT 140" and the
other "BAT 160." The BAT 140 light indicates
that either or both batteries have reached 140°F.
Check the battery temperature indicators, if in-
stalled, to determine which battery is over-
heating. The BAT 160 light indicates that either
or both batteries have reached 160°F.
Dual battery temperature indicators, (if in-
stalled), one for each battery, are provided to
give a readout of battery temperature so that
corrective action may be taken in the event of
battery overheat.
Main Battery Switch and Relays
SNs 24-230 through -259, -261, -262,
-263, and 25-061, -070 through -089,
and -091 through -102
One two-position ON–OFF battery switch
(Figure 2-2) is provided to interconnect the bat-
tery bus to the battery charging bus via the bat-
tery relay. This allows charging of the battery
from the generators or provides battery and
GPU power to the airplane systems. The bat-
tery switch, when in ON, provides a ground to
the battery relay.
When the battery switch is in ON, battery volt-
age is indicated on the DC voltmeter if no
other power source is connected to the battery
charging bus.
NOTE
Batteries are connected in parallel at
all times, including engine starts.
SNs 24-260, -264, and Subsequent,
and 25-090, -103, and Subsequent
Two battery switches (Figure 2-3) are located
on the center instrument panel between the
starter-generator switches. Each switch has
an ON and OFF position. If a switch is on and
the respective battery has approximately 16
volts available, the battery relay closes and the
LEARJET 20 SERIES PILOT TRAINING MANUAL
FOR TRAINING PURPOSES ONLY
FlightSafety
Figure 2-2. Battery Switch and DC
Voltmeter
Figure 2-3. Battery Switches
international
2-3