7
JLC680-2 Rev AA
April 2019
SECTION IV — OPERATION
4-1 GENERAL
This hoist is designed for safe operation within the limits of its rated
capacity. It is controlled by the “UP” and “DOWN” buttons of the
pushbutton station. Two-speed models utilize 2-step buttons, the
first step for operating the slow speed and the second for the fast
speed. Although the Coffing JLC is built with many features to
ensure safety, it is a requirement that a hoist operator understands
safe lifting practices. The following points must be observed.
Do not allow load to come in contact with the chain container.
If this situation exists reset the “UP” limit switch so that the
hook block stops below the chain container (See LIMIT SWITCH
ADJUSTMENT, page 8).
1. Do not overload the hoist.
2. Do not make extreme side pulls with the hoist.
3. Operate the hoist only in a hanging position with
adequate support.
4. Do not “sling” the load hook and chain around the load.
Use an approved sling.
5. Be sure there are no twists in the load chain as it travels into
the hoist housing. This condition should be constantly checked
on double chain hoists because it is possible for the load block
to be “capsized” or turned over one or more times.
6. Before raising a load, always check to see that it is held
securely in the hook or sling chains, etc. Raise the load only
until the load chain is taut and then double check the rigging
before continuing to raise the load.
7. Do not stand beneath a load! Do not move a load in such
a manner as to endanger personnel.
To avoid personal injury:
Do not use the equipment shown in this manual to lift, support, or
otherwise transport people, or to suspend loads over people.
8. Don’t lower into areas where visibility is obscured unless
someone else is guiding the operation.
9. Use common sense at all times when operating a hoist.
10. Do not operate if direction of hook travel is not the same as
indicated on button being pushed.
11. Do not operate unless hook travel limit devices function. Test
without load each shift.
12. Do not operate when hoist is not centered over load.
13. Do not operate if chain is not seated properly in sprockets or
sheave grooves.
14. Do not operate damaged or malfunctioning hoist.
4-2. OVERLOAD LIMITING PROTECTION
This hoist is equipped with a factory-calibrated overload limiting
clutch that will permit the lifting of loads within its rated capacity,
but will prevent the lifting of damaging overloads while the hoist is
being operated. If the load being lifted exceeds the lifting capability
of the overload clutch, the hoist motor will continue to run, causing
overheating of both the clutch and hoist motor. This condition should
be avoided by immediately releasing the “UP” button and reducing
the load to within the rated capacity of the hoist. See GEARING,
page 10, for additional instructions on this device.
The overload limiting clutch is an emergency protective device and
should not be used to measure the maximum load to be lifted, or to
sense the overload imposed by a constrained load. While the overload
limiting clutch will protect the hoist from damaging overloads, it will not
ensure that a load is within the rated capacity of the hoist.
SECTION V — MAINTENANCE
5-1. INSPECTIONS
A planned inspection routine should be established for this hoist
based upon frequency of use, severity of use, and environmental
conditions (Reference ASME Standard B30.16). Some inspections
should be made frequently (daily to monthly) and others periodically
(monthly to yearly). It is strongly recommended that an Inspection
and Maintenance Check List and an Inspector’s Report, similar
to those shown in Figures 10A and 10B, be used and filed for
reference. All inspections should be performed or overseen by a
designated inspector. Special inspections should be made following
any significant repairs or any operating occurrence leading one to
suspect that the hoist’s capability may have been impaired
5-2. LOWERING WITHOUT POWER
If the power fails with a load suspended, the hoist will automatically
stop. In an emergency the load can be lowered without power as
follows:
1. DISCONNECT HOIST FROM POWER SUPPLY AND REMOVE
ELECTRICAL COVER.
2. Refer to Figure 5. Open disc brake manually by using two
screwdriver blades, one on each side of the brake at a
point close to the brake spring posts. Apply pressure to the
underside of the armature plate (points “X”) to close the
solenoid and release the brake.
3. Use several quick releases instead of holding brake open
continuously. Do not exceed normal lowering speed.
Do not allow screwdriver blades to touch rotating friction
disc “C”.
Do not allow the load to descend rapidly. This causes the motor
to race and serious damage may result.
5-3. HOOKS
Refer to Figure 2.
1. Inspect hooks once daily for cracking, extreme wear or
spreading. Replace hooks showing any of these signs. If
the throat openings are spread wider than the maximum
permissible 15% increase listed here, the hooks have been
overstressed and must be replaced. Any hook that is bent or
twisted more than 10 degrees from the plane of an unbent hook
must also be replaced.
2. The hook latches should be inspected to ensure that they
close the hook throat opening in a secure manner when a load
is applied. Inspect the hook shank and nut for any stripping
of the threads or other damage. The hook nut should be fully
restrained by the retaining pin.
3. In addition to above, load hooks should be inspected for cracks
by the magnetic particle, dye penetrant or other suitable crack
testing inspection method. This should be done at least once
a year.
Содержание Coffing JLC Series
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