for horizontal wall mounting, rotate 90°.
Note 3: The brake nameplate states mounting
position; “horizontal, vertical above or vertical
below.” The brake must be mounted in that
position. Horizontal brakes rated 35 lb-ft and
less do not require modification to be mounted
vertical below.
Note 4: A dimple drilled into the motor shaft for
the hub set screw (16S), 90° from the key is
recommended for vertical mounting.
F. Position hub (16) and key (by customer)
on the motor shaft so outboard face of hub
will protrude approximately 1/32” to 1/16”
beyond face of last outboard friction disc.
(Position may be determined by assembling
friction disc(s) and stationary disc(s) onto
hub, noting hub position, and removing
disc(s).
Torque set screw (16S) as follows: 5/16
diameter - 13 ft-lb, 3/8 diameter - 24 ft-lb
and 1/2 diameter - 52 ft-lb. If brake utilizes
vertical mounting springs, do not assemble
them when measuring for hub location.
G. Reassemble friction disc (be sure friction
discs slide freely), spring (if vertical),
stationary discs, and pressure plate in
correct sequence and position. All parts
must slide freely. The universal mounting
pressure plate presently used has three
tapered reliefs on outboard face. However,
some older brakes used a pressure plate
with a single tapered
relief marked top, which must be installed
with relief facing manual release rod (146).
H. Mount support plate assembly, torque
screws to 50 in-lbs in endplate. Conical
spring washer installed under the screw
head. Flat washer used under the conical
spring washer only with aluminum support
plate. Be sure that assembly is mounted
with the solenoid in a vertical position
(plunger above frame) as shown when
brake is horizontal. If release rod (146) is
not in manual release position and has
allowed the mechanism to overadjust, it will
have to be reset before mounting support
plate. In this case, the lever arm (17) throat
will be near, or touching, the pinion (32)
teeth. Refer to Figure 6 and Self-Adjust
Maintenance. Loosen pressure spring cap
screw (19) until pressure spring (11) is free,
mount support plate assembly to endplate
and retighten spring cap screw until snug.
Do not overtighten! Torque to a maximum
of 8 ft-lbs.
I. Manually lift solenoid plunger to maximum
travel, and release. Complete electrical
connection. (See Section on Electrical
Connection of Brake.) Depress solenoid
plunger manually or electrically, and allow
it to snap up. Repeat this process several
times to set air gap on solenoid. (Check
Self-Adjust Maintenance Section for proper
gap measurement, or corrective action of
improper gap.)
J. Replace housing, nuts and manual release
knob.
II. Installation Procedure - 87,200 (See
Figure 1A)
As shown in the exploded view, Figure 1A,
the 87,200 Brake is very similar to the motor
mounted 87,000 Series. It is, however, a
self-supported, foot mounted unit, with an
integral bearing supported through-shaft. Since
disassembly is not required prior to mounting,
installation is simplified.
A. Bolt foot mounting bracket (34) to foundation
uses four 3/8-16 cap screws and lock
washers (not supplied). Torque cap screws
to 110 ft-lb specifications. Dowels are
recommended to maintain alignment.
B. For reference purposes, the endplate
mounting bolts, 1A, are torqued to 100-110
lb-ft for cast iron endplates; or 45-50 lb-ft for
aluminum endplates.
C. Do not exceed maximum overhung, or side
load ratings on output shafts. 100 lbs. on
housing end of brake, 150 lbs. on endplate/
foot stand end of brake. (Measured at 1”
from end of shaft).
D. See Section Electrical Connection of Brake.
Note:To remove housing for servicing of the
brake it is necessary to loosen the eccentric
bearing sleeve. Loosen the set screw on
the sleeve (35S) and, using a 3/16” drift pin,
rotate the sleeve on the shaft until loose
(about ±20°). Remove the housing nuts
(15) and release knob (148), and slide the
housing off the shaft. Reverse the procedure
for re-assembly.
III. Electrical Connection of Brake - All
Models
CAUTION 1: Inverter Motor and Special
Control Systems. This brake contains either
a single phase AC coil or DC coil that requires
instantaneous power within ± 10% of rating at
the coil. A separate power source is required
when this brake is used in conjunction with a
motor or control system that limits voltage or
current input (i.e. inverter motors) or causes a
ramping of the power supply.
CAUTION 2: Class H coils with terminals. Do
not bend lead wire crimp connection as this
causes a fatigue in the metal which may break
under vibration.
Note 1: Brake coil connections described
here cover common motor connections. For
nonstandard motor or control connections,
contact respective supplier or Stearns Div.
Note 2: Be sure lead wires to coil are not tight
or pinched, and that leads will not be rubbed
by friction disc, trapped between solenoid
plunger and frame, caught between lever arm
and endplate, or by linkage.
Note 3: On brakes with spacer heater, connect
to appropriate power source. Heater is to be
energized continuously, even during storage or
rusting may occur.
A. AC coils, single or dual voltage
1. Dual voltage coils may be factory precon-
nected for high voltage with wire nuts.
Checking coil connection is suggested. On
the 87,200 only, coil lead wire termination
is accessible at lead wire outlet of endplate
(2). Four lead style are marked on leads
for connection per Figure 4. Two unmarked
leads mean preconnection made for high
voltage. If reconnection of a dual voltage
coil is required (two unmarked leads) on the
87,200, housing (7) must first be removed
per Section and Figure 1A. Reconnect coil
for appropriate voltage as shown in Figure 4.
Bring out line leads.
2. On single voltage coils, connect coil to any
two leads on single or three-phase motors
of the same voltage as the brake. Refer to
brake nameplate and coil number for correct
voltage and frequency. See Figure 4 for dual
voltage coil connection and connect to any
two leads of single or three-phase motor of
the same voltage. The brake can also be
wired to external switch contacts providing
proper voltage other than that used to
control the motor. Normally, the motor and
brake contacts are interlocked.
B. Connecting AC solenoid coils on dual
voltage 230/460 three-phase motors
To use a 230 volt coil (or a 230/460 dual
voltage coil connected for 230 volts) with a
230/460 dual voltage three-phase motor, the
brake leads are connected across two motor
terminals as shown in Figures 2 and 3 or other
equivalent combinations. If a 230 volt brake coil
is connected as shown in Figures 2 and 3 the
motor can be operated on either 230 volts or
460 volts with no effect on brake operation.
AC Voltage Coil Connection
C. DC coils - all models
1. All Stearns DC coils are single voltage
dual winding. A high current pull-in winding
is initially energized to start the plunger
movement, while a low current holding
winding is momentarily shunted from the
circuit until the plunger has pulled in. The
older design incorporated a mechanical
switch mounted to the solenoid frame and
actuated by an arm mounted to the plunger
to bring the holding winding into the circuit.
In addition, coils over 48 Vdc have an arc
suppression module in parallel with the
switch contacts to protect the contacts
from arc erosion and suppress EMI. The
polarity of the incoming power supply is
immaterial with the mechanical switch. The
new electronic switch design incor-porates
an electronic timing circuit to allow the
plunger to pull in, then electrically switch to
the holding winding. Polarity of the power
supply to the electronic switch and coil must
be maintained. Refer to Figure 5 for proper
wiring.
Caution! Never use a series resistor to drop
power supply voltage to the coil as brake
malfunction will result.
2. Due to high initial current demands of a
DC solenoid, a separate DC power source
Figure 1A
Figure 2 Figure 3
