Operator`s manual

Ladder Extension and Retraction - when the Ladder Extension Joystick (1) is moved toward A+, current is

directed via the Current Regulator (13) to the A side of the Extension solenoid (18), causing the

corresponding Proportional Valve to open and the ladder to extend. When the Ladder Elevation Joystick

(1) is moved toward B-, current is directed via the Current Regulator (13) to the B side of the Extension

Solenoid (18) causing the corresponding Proportional Valve to open in the opposite Direction and the

ladder to retract.

When the ladder extension is about five feet from its maximum, speed is reduced automatically by a micro

switch (4). The lug on a Limit Switch Activating Cam closes the micro switch (see Figure 8-9, numbers 5

and 7) and current is reduced to the A side of the Extension Solenoid (18) by two resistors (9), causing the

rate of ladder extension to slow.

When the ladder is fully extended, a second micro switch (5) contacts the Limit Switch Activating Cam

(see Figure 8-9, number 8). The micro switch opens and current is cut to the A side of the Extension

Solenoid. The Extension Solenoid operates the corresponding Proportional Valve, preventing further

extension of the ladder using the Ladder Extension Joystick.

When the ladder is fully retracted, a micro switch (6) contacts the Limit Switch Activating Cam (see Figure

8-9, numbers 5 and 4). The micro switch opens and current is cut to the B side of the Extension Solenoid

(18). The Extension Solenoid operates the corresponding Proportional Valve, preventing further retraction

of the ladder using the Ladder Extension Joystick.