LEESON 210 C-Face Motors - Manual (Page 3)

connected as shown in figures 4 and 5 the
motor can be operated on either 230 volts or
460 volts with no effect on brake operation.
III. General Maintenance
Warning! Any mechanism or load held in posi-
tion by the brake should be secured to prevent
possible injury to personnel or damage to
equipment before any disassembly of the
brake is attempted or the manual release lever
is operated on the brake. Observe all
cautions
listed at the beginning of this manual.
Note 1: Replacement part kits for many items
are available and contain retrofit instructions.
Note 2: Do not lubricate any part of the brake
as this may cause a malfunction and/or loss of
torque.
A. Coil replacement
All standard NEMA AC voltage coils are avail-
able in kits. Select coil kit from appropriate
replacement parts list for the particular brake
series being serviced.
B. Friction disc replacement
Note: Replace friction discs in single disc
brakes when wear surface area is one half the
original disc thickness (1/4
″). In multiple disc
brakes, replace all friction discs when throat of
lever arm is within 1/16
″ of touching teeth of
pinion.
C. Self-adjust maintenance
Since the self-adjust brake automatically
adjusts itself for friction disc wear, maintenance
is held to a minimum. The solenoid is factory
set with a 13/16
″ to 15/16″ air gap, and
requires no resetting, even when changing fric-
tion discs. The gap is determined by the posi-
tion of wrap spring stop (76). Should air gap
change, follow the steps listed below:
1. If (stop) screws (76S) had been loosened
and retightened, the air gap may require
resetting. The gap is measured between
mating surfaces of plunger (29) and solenoid
frame (79), and may be increased by raising
slightly, or decreased by lowering slightly,
wrap spring stop (76). Be sure to retighten
(stop) screws (76S). Manually lift plunger to
maximum travel and release. Depress
plunger, manually or electrically, and allow it
to snap up. Repeat several times, then
recheck air gap for factory setting of 13/16
″
to 15/16 ″.
Note: To measure solenoid air gap on verti-
cally mounted brakes, grasp solenoid link to
hold plunger in a free horizontal position and
move toward solenoid frame until spring
pressure is felt. Holding firmly in this position
measure air gap between mating (ground)
surface on solenoid frame and solenoid
plunger. Adjust to proper gap as directed in
Self-Adjust Maintenance. Check gap by
again holding plunger as directed.
2. Tang of wrap spring must be below, and
must make contact with, wrap spring stop
(76) when
solenoid lever
(28) is manual-
ly raised. If
stop is bent
outward, allow-
ing tang to
bypass it,
rebend to
square posi-
tion, assemble
correctly, and reset solenoid air gap as
described in Paragraph 1.
3. Should air gap have decreased or disap-
peared, the solenoid lever and pinion
assembly (8) may have
become contaminated
due to lubrication or
residue as a result of
overheating of brake.
For reference purposes
refer to Figure 7. Tang A
should align with the
centerline of hole B.
Use kit #5-66-7371-00 if
replacement is neces-
sary.
4. Check condition and positioning of
pinion and rack assembly. Replace parts as
necessary with complete assemblies.
D. Solenoid lever and pinion assembly
replacement
If pinion teeth are worn, replace entire assem-
bly. Consult appropriate parts list for kit num-
ber. Check sector gear of lever arm for wear.
If sector gear teeth of lever arm are worn,
replace entire lever arm assembly available as
a kit from appropriate repair parts list. Also
check pinion teeth for wear.
E. Drain plug removal (WASHGUARD
brakes only)
If moisture has accumulated inside the brake
enclosure, remove the drain plug (location
shown in Figure 1). Replace plug after fluid has
drained.
IV. Troubleshooting
A. If brake does not stop properly or
overheats, check the following:
1. Is manual release engaged, and is motor
energized?
2. Friction discs may be excessively worn,
charred or broken.
3. Hub may have become loose and shifted
on shaft.
4. Is hub clean and do friction discs slide
freely?
5. Are controls which govern start of brake
cycles operating properly?
6. Are limit switches, electric eyes, etc. func-
tioning properly?
7. On vertically mounted brakes, are
springs in place in disc pack?
See P/N 8-078-937-06.
8. Have mounting faces loosened?
9. Pressure spring may be improperly assem-
bled or broken.
10. Is solenoid air gap adjusted correctly?
(See Self-Adjust Maintenance ,
Section III, Item D.)
11. Check linkage for binding. The approximate
pressure applied to the top of the solenoid
link to move plunger is:
If excessive force is required, determine
cause of binding and correct. Do not over-
look bent, worn or broken plunger guides
as a possible cause for binding.
12. Solenoid lever stop (22) must be in place
on support plate.
13. Solenoid may not be energizing and releas-
ing the brake. Check voltage at the coil and
compare to the coil and/or nameplate volt-
age rating.
14. A voltage drop may be occurring. If exces-
sive drop in voltage is noted, check wire
size of power source. Correct as needed.
Note: A method to check voltage at coil is
to insert a block of wood of the approxi-
mate thickness of the solenoid air gap
between the solenoid frame and plunger.
(The block will prevent brake from releas-
ing when coil is energized.) Connect volt-
meter leads at the coil terminals or lead
wires. Energize coil. Voltmeter needle will
not fluctuate and reading can be taken.
Reading should be taken immediately and
the coil de-energized to prevent over-heat-
ing of the coil. Compare voltage reading
with coil rating.
15. Check slots of endplate for wear at the
areas where stationary discs are in contact.
Grooves in the slots can cause hang-up or
even breakage of ears of stationary discs.
If grooving is noted, replace endplate.
16. Check that heads of mounting bolts do not
extend above wear surface of endplate.
17. Check pressure spring length to insure cor-
rect compressed height. Approximate origi-
nal spring lengths are given in the following
table so that correct setting may be verified
and corrected if necessary. With worn fric-
tion discs, add amount of wear to the
approximate spring length shown in table.
Figure 6
Figure 7
16 lbs #8 coil
9 lbs #6 coil (25 lb-ft)
5-1/2 lbs #6 coil (15 lb-ft)
3 lbs #5 coil
3
AC Voltage Coil Connection
Figure 3
3 and 4 2 1 High voltage
– 2 and 4 1 and 3 Low voltage
Tie Leads Power Line B Power Line A For
Figure 4 Figure 5
Class B Coil (black)
Air
gap