8
JLC680-2 Rev AA
April 2019
Figure 2 — Hook Inspection
Hoist Capacity
"X" Dimension
Top Hook
Bottom Hook
1 Ton & Under
1-11/32”
1-7/32”
2 Ton
1-11/32”
1-11/32”
(*) Maximum permissible throat opening of hook.
5-4. CHAIN
Chain inspection and lubrication are the most important aspects of
hoist maintenance. Chain is to be kept clean and lubricated (See
LUBRICATION, page 9) at all times. Visually check the chain every
time the hoist is used. Hoist must not be operated when the chain is
twisted or kinked. Chain inspection will not usually require removal
of the chain from the hoist, but the chain should be run through the
hoist enough so that every link is made visible for inspection.
Load chain that is kept clean and lubricated is essential to the
safe operation of a hoist. Failure to do so may cause serious
hoist damage, spillage of chain from chain container (when
equipped). cross-linked chain resulting in dropped loads
and other hazardous conditions that may result in injury or
death. Chain contaminated with foreign substance must be
removed from service, cleaned and lubricated before hoist
use can continue.
a. Check each link for gouges, nicks, weld splatter, corrosion,
and distortion.
b. Inspect each link for wear to the diameter of the link. The
nominal link diameter is 0.281 inch. If the diameter of any
link of 0.281 chain is worn to less than 0.225 inch, the entire
chain must be replaced.
c. 1. Check the chain for overall wear or stretch by selecting
an unworn, unstretched length of chain (at the slack end,
for example). Let the chain hang vertically with a light load
(about 20 pounds) on the chain to pull it taut. Use a large
caliper to measure the outside length of a convenient
number of links (about 12 inches). Measure the same
number of links in a used section of chain and calculate the
percentage increase in length of the worn chain.
2. If the length of the worn chain is more than 1-1/2%
longer than the unused chain (0.015 inch per inch of chain
measured), then the chain should be replaced. If the chain
is worn less than 1-1/2%, check it at several more places
along its length. If any section is worn more than 1-1/2%,
the chain should be replaced
d. The chain used in the hoist is accurately calibrated to
operate over the load sprocket and is very carefully heat
treated for maximum wear life and strength.
Do not weld or join hoist load chain.
Do not substitute another manufacturer's chain in this hoist.
Damage or wear, beyond the stated limits, to any portion of
the chain requires that the entire length of chain be replaced.
CHAIN REPLACEMENT WITH CHAIN IN HOIST
Refer to Figures 3 & 4.
1. Run hook up to its top limit.
2. DISCONNECT HOIST FROM POWER SUPPLY and remove the
electrical cover.
3. Using a screwdriver, pry the spring guide plate out of the slots
in the limit switch nuts (See Figure 3). Turn the gold nut back to
about the center of the threaded screw. Do not disconnect the
wires from the limit switches.
4. Remove the load block assembly from the old chain. On
double-chained hoists detach the chain from the chain support
and pull it through the load block assembly (See Figure 4).
5. Make a “C” shaped chain link by grinding through the end link
on the load end of the old chain.
6. Using the “C” link, attach the new chain to the load end of the
old chain. Be sure that the welds of the upstanding links of the
new chain will face outward from the load sheave. The end links
must be oriented for attachment to the dead-end attachment
pin and the chain support (double-chained only) without any
twist in the chain. (See Figure 23)
7. With the electrical cover off, connect the hoist to the power
supply. Be sure that the green ground wire is properly grounded
(See INSTALLATION 3b, page 4).
8. Carefully jog the “UP” button and run the joined pieces of chain
into the hoist until about 15" of the new chain comes out the
other side.
9. DISCONNECT HOIST FROM POWER SUPPLY.
10. Remove the “C” link and the old chain. Remove the chain
stop by prying off its retaining ring with a flathead screwdriver.
If attached, remove the old chain from the chain stripper by
removing the retainer clip and attachment pin.
11. Attach the chain stop to the slack end of the new chain by
capturing the 12th link with the two stop halves positioned with
their tapered ends pointing towards the hoist. Slide the sleeve
over the halves and attach the retaining ring. If you are not
using a chain container, attach the slack end of the new chain
to the side of the hoist using the attachment pin and retainer
clip. DO NOT allow twists in the chain.
12. Adjust the lower limit switch (See ADJUSTING LOWER LIMIT,
page 8).
13. Attach the bottom block on single-chained hoists using a
new load block pin
(See Figure 23). On double-chained hoists,
feed the chain through the load block (welds of the upstanding
links will be in towards the sheave) and fasten the end of the
chain to the chain support using a
new chain support pin
(See Figure 23).
Be sure there are no twists in the chain
.
14. Adjust the upper limit switch (See ADJUSTING UPPER LIMIT,
page 8).
Figure 3 — Limit Switch Assembly
