Horsepower Limiter Board - Genie S-80 Service Manual

Section 7 - Repair Procedures
PLATFORM CONTROLS
8 Set the dual (lo) range: Press down the foot
switch, then move the control handle all the
way to the position. Adjust the voltage
RETRACT
to 8.9V DC. Turn the dual range trimpot
adjustment screw clockwise to increase the
voltage or counterclockwise to decrease
the voltage.
9 Start the engine and move the engine idle
control switch to foot switch activated high
idle (rabbit and foot switch symbol). Lower
the boom to the stowed position.
Engine should be at normal
operating temperature.
10 Start a timer and record how long it takes for
the boom to fully extend. Adjust the
max-out trimpot to achieve an 140 to 170
second cycle time.
11 Start a timer and record how long it takes for
the boom to fully retract. Adjust the dual range
trimpot to achieve an 80 to 110 second cycle
time.
If the function cycle time is not
achievable, check the relief valve
pressure. See 10-2, Valve
Adjustments - Function Manifold.
12 Turn the engine off and re-connect the
volt meter.
13 Pull out the Emergency Stop button to
the position.
ON
14 Press down the foot switch and then move the
control handle all the way to the
position. Record the maximum voltage reading.
15 Start the engine.
16 Start a timer and simultaneously move the
control handle all the way to the
position. Note how long it takes to reach the
maximum voltage recorded in step 14. This is
the ramp speed.
17 Set the ramp rate: turn the trimpot to obtain
a 3 second ramp speed. Turn the
trimpot clockwise to increase the time or
counterclockwise to decrease the time.
7 - 6
Boom up/down specifications
Threshold
Boom extend - Max-out
Cycle time
Boom retract - Dual (lo) range
Cycle time
Ramp rate
1-2

Horsepower Limiter Board

The horsepower limiter board is responsible for
governing drive pump output. It senses engine
rpm from the alternator. The horsepower limiter
board senses drops in rpm normally due to
increased drive resistance (rough terrain or
incline), and decreases voltage to the drive
controller which in turn decreases voltage to the
drive pump, thereby reducing pump output to
maintain optimum engine rpm and horsepower.
Three adjustments are required for optimum
performance.
How to Adjust the Horsepower
Limiter Board
EXTEND
EXTEND
Genie S-80 & Genie S-85
Service Manual - First Edition
140 to 170 seconds
80 to 110 seconds
The engine rpm must be
correct before performing this
procedure. See Maintenance
Procedure B-12, 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.
Part No. 34032
3.5V DC
9.75V DC
8.9V DC
3 seconds