SERVICE MANUAL & ICA
8750 AMPHIBIAN/SEAPLANE FLOATS ON CESSNA 208/208B
Revision C
Page 77 of 104
P/N 1005723 Doc. No. W8750-24-01
system is installed standard for all new 8750
installations starting May, 2012.
BASIC DESCRIPTION
The following electrical systems are added
with the installation of Wipline 8750 floats
on the Cessna 208/208B:
1.
24V DC Hydraulic pumps (2), each
pump with its own dedicated circuit
breaker
2.
Gear selector head, for changing pump
flow directions to actuate the landing
gear up and down, and indicate gear
position
For detailed schematic information
regarding the electrical system, refer to the
previously listed Wipaire, Inc. wiring
diagrams.
ELECTRIC HYDRAULIC PUMPS
The installed 24V DC electrically reversing
hydraulic pumps are wired independently to
allow failure of one pump without affecting
the other pump. The pump is electrically
shut-off in the up and down directions by a
fluid pressure switch that cuts pump power
when sufficient hydraulic pressure is
obtained in the gear system. Gear swings
should take less than 45 seconds with both
pumps operating. If the gear cycle time is
greater than 45 seconds it is likely that one
pump is not pumping efficiently and/or not
operating correctly.
This can be verified by pulling each pump
breaker to see if the system functions on one
pump, but not the other.
GEAR SELECTOR HEAD
The installed gear selector head is similar to
units used in several other models of
Wipline floats. This selector head switches
current directions to the electric pumps,
reversing their pumping direction. It also
indicates gear positions using four blue and
four green incandescent lights. The lights
for the nose gear are turned on with a
magnetic switch that senses a magnet in the
hydraulic cylinder piston. The lights for the
main gear position are triggered by inductive
proximity switches that are triggered by
metal flags on the main gear arm. Lights are
a cartridge style and can be replaced by
pulling them out from the bezel. A
suspected defective light can be quickly
replaced with an adjacent light for
troubleshooting a suspected defective bulb.