BOOM 2250 SERVICE/MAINTENANCE MANUAL
4-14
Published 07-19-16, Control # 249-01
BOOM HOIST RATCHET AND PAWL
ADJUSTMENT
General
See Figure 4-10 for the following information.
These instructions apply only to the ratchet and pawl
provided on the right, rear drum (drum 2 is used for the boom
hoist when equipped with the MAX-ER 2000 attachment).
The pawl limit switch (6) must be properly adjusted to ensure
proper operation of the boom hoist drum.
When the drum 2 park switch is on, the drum 2 park brake is
applied, the boom hoist control handle is disabled, and the
pawl (5) is engaged. When the pawl is engaged, the pawl
limit switch closes the electric circuit to the crane’s
programmable controller. This action prevents drum 2 from
being operated in either direction. However, drum 3 is
operable when drum 2 is parked.
When the drum 2 park switch is off, the drum 2 park brake is
released, the boom hoist control handle is enabled, and the
pawl is disengaged. When the pawl is disengaged, the limit
switch opens the electric circuit to the crane’s programmable
controller. This action allows operation of drum 2 in either
direction, as long as drum 3 is parked.
If the operator attempts to operate either drum 2 or drum 3
when the other drum is not parked, the operating limit alert
comes on and FUNCTON NOT PARKED appears on the
digital display.
The pawl limit switch is factory set and does not require
periodic adjustment. However, the limit switch must be
adjusted if any parts are replaced or checked if the drum is
not operating properly.
Adjusting the Pawl Limit Switch
See Figure 4-10 for the following procedure.
1. Loosen the screw (8) so the limit switch lever (10) is free
to rotate on the shaft (11).
2. Disengage the drum 2 pawl by toggling the drum 2 park
switch to OFF. It may be necessary to jog the hoist
control slightly before the pawl will disengage the
ratchet (4).
3. Rotate the limit switch lever until the roller (9) is against
the pawl. Hold the lever in this position.
4. Turn the shaft, not the lever, counterclockwise until the
limit switch clicks open. Hold the shaft in this position.
5. Make sure the roller is against the pawl and securely
tighten the screw in the lever to lock the adjustment.
6. Verify proper operation:
• Engage the drum 2 pawl by toggling the drum 2 park
switch to ON. Try to operate drum 2. Drum 2 should
not operate in either direction. Drum 3 should be
operable.
• Disengage the Drum 2 pawl by toggling the drum 2
park switch to OFF. Toggle the drum 3 park switch to
ON. Try to operate drum 2. Drum 2 should operate
in either direction. Drum 3 should be inoperable.
7. Readjust the limit switch if required.
Adjusting the Tension on the Return Spring
See Figure 4-10 for the following procedure.
Adjust the eyebolt (2) so the return spring (3) has enough
tension to fully engage and hold the pawl (5) against the
ratchet (4).
WARNING
Moving Parts Hazard!
Death or serious injury may occur from moving
machinery. To make adjustments, the engine must be
running, and the drums and the pawl must be operated.
Stay clear of the drums and the pawl while either is being
operated. Maintain constant communication between the
operator and the adjuster so the drums and pawl are not
operated while the adjuster is in contact with the parts.
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