HOISTS 14000 SERVICE MANUAL
5-10
Published 09-05-14, Control # 226-02
4. Test block-up limits for proper operation using either of
following methods:
a. BOOM LOWERED: Manually lift each weight —
one at a time — while engine is running. Load drum
should not operate in HOIST direction and boom/
mast hoist should not operate in LOWER direction.
b. BOOM RAISED: Slowly hoist each load block and
weight ball — one at a time — against weight.
When chain goes slack, corresponding load drum
should stop HOISTING and boom/mast hoist should
not operate in LOWER direction.
Spring Tension Checking and Adjustment
See Figure 5-7 for following procedure.
Adjust limit switch spring tension so there is enough force to
lift the weight of the chain and rotate the actuating lever when
the weight is lifted.
1. Lower boom onto blocking at ground level.
2. Remove cover (11) from the limit switch housing.
3. Allow the weight of only the chain to pull down on the
lever. The spring should rotate the actuating lever past
the trip-point shown in Figure 5-7
.
- If the actuating lever does not rotate past the trip
point, troubleshoot the cause.
- If the spring tension is found to be insufficient, either
replace the spring (3) or adjust the eye bolt (4) as
needed, then retest.
Trip Setting Adjustment or Switch
Replacement
See Figure 5-7 for following procedure.
1. Lower the boom onto blocking at the ground level.
2. Remove the cover (11) from the block-up limit switch
enclosure (4).
3. If installing a new switch, remove the limit switch.
Then, remove the limit switch lever (9) and install it onto
the new limit switch. Do not tighten the lever onto the
switch yet.
Install the new limit switch and any other removed
components.
4. Set the trip point of the limit switch:
a. Temporarily unhook the spring from the actuating
lever (7). Hold the actuating lever at the Trip
Position shown in Figure 5-7
.
b. With the screw (2) loose, hold the roller (8) of the
limit switch lever (9) against the actuating lever (7).
c. Turn the switch shaft (10) counter-clockwise (for
right-hand configuration) or clockwise (for left-hand
configuration) only enough to “click” the limit switch
open. Then securely tighten the screw (2) in the limit
switch lever.
d. Pull the actuating lever downward past the Trip
Position. Then slowly raise the actuating lever while
listening for the switch to trip. The switch should trip
at the position shown in Figure 5-7
. Readjust and
retest as necessary.
e. Place the spring back onto the actuating lever.
5. Reinstall the enclosure cover. Test the limit switch for
proper operation (see "Weekly Maintenance”).
CAUTION
Avoid Sheave Damage
Use extreme care when testing block-up limits when
boom is raised. If a block-up limit fails to stop load,
immediately stop load by moving drum control handle to
off; otherwise, two-blocking may occur.
To Next Page
Loading...
Need help?
General
