Coffing Hoists EC Series, Operating, Maintenance & Parts Manual

Page: 16 / 48

16
P/N EC680-7 April 2017
Order # 5041558-0 & 5041679-0
c. Install new suspension assembly and tighten socket head screws
to 75 ft-lbs torque.
Due to the off-center hood or lug hole, the suspension yoke
can be installed in the hoist in two different ways. With the hoist
level, the hook or lug must always be directly over the bottom
hook. Refer to Figure 5-4 for the proper yoke orientations for
single, double and triple chain hoists.
5-5. CHAIN REPLACEMENT
(OLD CHAIN STILL IN HOIST)
Refer to Figure 5-4, Chaining and Suspension Diagrams, and proceed
as follows:
a. Run the load block up to its top limit.
b. Disconnect power from the hoist and remove the short end cover.
c. With a screwdriver, push the spring guide plate (No. 1 Figure 5-1)
out of the slots in the limit switch nuts. Turn the brass slotted nut
(No. 2) back to about the center of the threaded screw. DO NOT
DISCONNECT THE WIRES FROM THE LIMIT SWITCHES.
FIGURE 5-3. CHAINING HOIST
d. Remove the load hook assembly from the old chain.
e. Make a “C” -shaped chain link by grinding through one side of
the end link of either the old or new chain. See Figure 5-3.
f. Hook the special “C” link to the end link of both chains to join
them. BE SURE the welds of the upstanding links of the new chain
are out away from the load sheave, and that proper orientation is
observed for attachment of the slack end in paragraph j. below.
Note
On triple chain hoists be sure all welds are aligned like the
welds on the old chain. It may be necessary to cut a link from
one or both ends of the chain to accomplish this.
g. With the end cover off, connect the hoist to power supply. Be sure
the green ground wire is properly grounded.
h. Carefully jog the “UP” button and run the joined pieces of chain
into the hoist until about 12 inches of the new chain comes out the
other side.
i. DISCONNECT POWER from the hoist.
j. Remove both the “C” link and the old chain from the slack end
pin (No. 28, Figure 8-6). This can be accomplished by depressing
the pin against the slack end spring (29) with a small screwdriver.
Remove the soft split link (23) from the old chain and attach the
link to the new chain. Depress the slack end pin and install the
split link observing proper orientation of the slack end of the chain
when secured. Avoid twists in the chain.
k. Adjust the lower limit switch per paragraph 5-2b.
l. Attach the bottom hook on single-chained hoists to the loose end
of the chain. On double-chained hoists, feed the loose end of 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 dead
end lug (No. 19 Figure 8-6).
Note
On triple chain hoists feed the loose ends of the chain
through the load block (welds away from sheave) around the
idler sheave in the hoist, and to the center of the load block.
m. Adjust the upper limit switch per paragraph 5-2.a.
n. Lubricate the new chain per paragraph 5-6.a and perform an
operation test of the hoist.
5-6 LUBRICATION
Proper lubrication is necessary for long, trouble-free hoist operation.
Refer to the following and to Table 5-1, Recommended Lubrication
Schedule, for lubrication points, type of lubricant, and frequency of
lubrication.
a. Load Chain – Clean the load chain with a non-acid and non-
caustic solvent and coat with SAE90 gear oil. Wipe excess
oil to prevent dripping. If the hoist is used in an atmosphere
containing abrasive dust, the chain should be cleaned and oiled
more frequently. Never apply grease to the chain.
b. Gearing – The gear case of the hoist is filled at assembly
with 46 oz. of a gear oil containing special friction reducing
additives.
The use of gear oils other than that recommended in Table
5-1 can cause brake chatter or can render the load brake
incapable of holding a load. A 48-oz. container of this oil is
available from COFFING. (Part No. 14J1).
1. To check the oil level, remove the 1/8” pipe plug from the
side of the hoist. With the hoist hanging level, transmission
oil should be even with the edge of the tapped plug hole.
2. The length of time between necessary oil changes will
depend on the severity of use the hoist receives. In general,
the oil should be changed every 12 months of normal
operation, or every 200 hours of actual hoist on-time.
Very heavy use or operation in high ambient temperatures
(over 105ºF) will require that oil be changed more often. An
indication of the need for oil replacement is load brake noise.
If an erratic tapping sound is made when lowering a load, the
oil should be changed.
c.
Limit Switch Shaft
– To prevent rust, the threaded limit switch
shaft should be given a light coat of grease or be sprayed with
a general purpose lubricant.
d. Idler Sheave Bearing (double and triple chain models only) –
Use a grease gun to put about a teaspoon of grease through
the grease fitting in the bottom block shaft. Avoid pumping an
excessive amount of grease into the bottom block. On triple
chain hoists, use a grease gun to lubricate the idler sheave in
the hoist until fresh grease pumps from the end of the sheave
bearing.
e. Hook Bearing – Apply a few drops of SAE 30 oil around the
edge of the bearing.