13. Attach the bottom block on single-chained hoists using a
new load block screw (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).
Chain Replacement with No Chain in Hoist
Refer to Figure 4.
1. DISCONNECT HOIST FROM POWER SUPPLY and move
hoist to a work table. Remove the electrical cover, electrical
panel and the electric brake assembly.
2. Detach the chain stripper from the bottom of the hoist.
3. Insert the new chain between the load sheave and the chain
guide. Feed the chain into the hoist by manually turning the
brake hub. Allow about 15" of chain below the hoist on the
slack end. Be sure the welds of the upstanding links are out
away from the load sheave and that proper orientation is
observed for attachment of the slack end. Also be sure the
load hook assembly (if already attached to the chain) is
toward the center of the hoist or to your right looking from
the transmission end.
4. Reinstall the chain stripper (with the chain anchor on double-
chained hoists, See Figure 4) observing proper chain
alignment and avoiding any twist in the chain.
5. Follow steps 11 through 14 in previous section, CHAIN
REPLACEMENT WITH CHAIN IN HOIST, to complete the
chain replacement procedure.
NOTE: Inspect chain guides and load sheave for wear,
replace as needed.
LIMIT SWITCH ADJUSTMENT
IMPORTANT: Before placing hoist in operation, check the limit
switch adjustment. Limit switches are provided to protect the
hoist against damage resulting from overtravel or to allow setting
the hook travel within the factory-set limits of travel. The standard
limit switch is designed for lifts of 50 ft or less on single-chained
hoists and 25 ft or less on the 2 ton, double-chained models. The
long lift limit switch allows for the maximum amount of lift, which
is 134 ft on 1/2 ton and under models, 143 ft on the 1 ton
models, and 71 ft on the 2 ton models.
The upper and lower limit switch adjusting nuts are color-coded
gold and silver respectively. Each limit nut has 10 slots for fine
adjustment, and the increment of adjustment is such that one
slot is equivalent to approximately one link of chain travel with
the standard limit switch. Movement of the limit switch nuts
toward or away from each other increases or decreases the
hook travel respectively.
Adjusting Upper Limit (Gold Nut)
Refer to Figure 3.
1. Suspend the hoist. For single chain models raise the load
block until there is a minimum clearance of 2" from the hoist
housing and the top of the block. Double chain models
require a minimum clearance of 1" from the chain support to
the top of the load block.
2. DISCONNECT HOIST FROM POWER SUPPLY and
remove the electrical cover.
3. With a screwdriver, pry the spring guide plate out of the slots
in the limit switch nuts.
4. Turn the slotted gold nut toward its limit switch until the
switch “clicks” then turn two slots farther. Release the spring
guide plate and be sure it slips back into the slots in both
limit switch nuts. Do not disturb the silver slotted nut if it has
been set previously.
Adjusting Lower Limit (Silver Nut)
Refer to Figure 3.
1. Suspend the hoist. Carefully lower the load block to a point
where the slack-end loop of the chain hangs down 6" or
more from the hoist housing (or the limit desired in any
particular application allowing the minimum 6"). There
should be a minimum clearance of 1½" between the chain
stop and bottom of hoist.
2. DISCONNECT HOIST FROM POWER SUPPLY and
remove the electrical cover.
3. With a screwdriver, pry the spring guide plate out of the slots
in the limit switch nuts.
4. Turn the slotted silver nut toward its limit switch until the
switch “clicks,” then turn two slots farther. Release the spring
guide plate and be sure it slips back in the slots in both limit
switch nuts. Do not disturb the gold slotted nut if it has been
set previously.
8
There are wires running through the hoist. Carefully
ease the hoist sections apart. Do not jerk them apart.
Double-Chain
Only
Figure 4 — Chain Replacement
Diagram
If the wires running to the limit switches are ever
disconnected for any purpose, be sure to replace
wires in accordance with the correct wiring diagram
(See Figures 9A, 9B, 9C & 9D).
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