Horsepower Limiter Board - Genie S-60 Service Manual

Third Edition • First Printing
1-2

Horsepower Limiter Board

The horsepower limiter board (HPL) is responsible
for governing drive pump output. Receiving engine
rpm signals from the alternator, the HPL senses a
drop in rpm normally due to increased drive
resistance due to operation on an incline or over
rough terrain. Instantly, the HPL decreases voltage
to the drive controller which in turn decreases
voltage to the drive pump. Decreased voltage
adjusts the output of the drive pump to maintain
peak engine performance.
For optimum performance, three adjustments are
required.
How to Adjust the Horsepower
Limiter Board
The engine rpm must be
correct before performing this
procedure. See Maintenance
Procedure B-6, Check and
Adjust the Engine RPM.
Do not adjust the horsepower
limiter board unless the static
battery voltage is above 12V DC
and the alternator is operating
properly with 12.5 to 14.5V DC
output.
Gasoline/LPG models: Perform
this procedure in gasoline mode.
1 Remove the fasteners from the platform
control box lid.
2 Open the control box lid and locate the
horsepower limiter board.
Electrocution hazard. Contact
with electrically charged circuits
could result in death or serious
injury. Remove all rings, watches
and other jewelry.
Part No. 65196
a
3 Connect the black(-) lead from a DC volt meter
to the number 2 terminal, and the red(+) lead to
the number 10 terminal.
Genie S-60 & Genie S-65
Section 7 • Repair Procedures
PLATFORM CONTROLS
Platform control box
a horsepower limiter board
12V DC or greater
ground
engine rpm sensor
not used
not used
low drive speed limit switch
not used
not used
not used
output to drive controller
Horsepower limiter board
a "A" trimpot maximum voltage
output to the drive controller in the
stowed position
b "B" trimpot maximum voltage
output to the drive controller in the
boom raised or extended position
c "C" trimpot reaction rate or how
fast the voltage output reacts to
the change in engine rpm
a
b
c
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