Warner Electric Electrically Released Motor Brake Module for EM-MBFB and EUM-MBFB - Manual (Page 4)

4 Warner Electric • 800-825-9050 P-1337 • 819-0314
Foreign Materials
If units are used on machinery where fine,
abrasive dust, chips or grit are dispelled into the
atmosphere, a screen over the ventilation holes
may be necessary.
Where units are used near gearboxes or
transmissions requiring frequent lubrication, means
should be provided to protect the friction surfaces
from oil and grease to prevent serious loss of
torque.
Oil and grease accidentally reaching the friction
surfaces may be removed by wiping with a rag
dampened with a suitable cleaner, which leaves no
residue. In performing this operation, do not
drench the friction material. If the friction materials
have been saturated with oil or grease, no amount
of cleaning will be completely effective. Once such
a unit has been placed back in service, heat will
cause the oil to boil to the surface, resulting in
continued torque loss.
Brake Release Adjustment
Instructions for setting the
optimum release voltage of permanent magnet
applied/electrically released brakes.
The following procedure will result in the brake
releasing and allowing the load to be free to
move. Be sure the load is in a safe condition
before proceeding with this process.
In a permanent magnet applied/electrically
released brake, the attractive force between the
brake surfaces is created by permanent magnets.
The brake is electrically released by applying DC
power to the electro-magnetic coil in the brake
that opposes the permanent magnets. Electrically
released brakes are polarity sensitive: the positive
lead of the power supply must be connected to
the positive (red) lead of the brake, and the
negative lead of the power supply must be
connected to the negative (black) lead of the
brake. The power supply applied to the brake
must also be adjustable so that the optimum
release voltage for each individual brake can be
determined and set.
The following procedure describes
how to set the adjustable power supply to the
optimum release point of the brake. A volt-meter
is required to perform the procedure.
No power is applied to motor during this
procedure. Power normally supplied by motor
to brake control should be supplied by
alternate method.
After control is adjusted per steps below,
brake control may need to be fine tuned
(adjusted) with motor running to compensate
for any changes in supply voltage used.
1. With power off, connect the positive lead of
the power supply to the positive (red) lead of
the brake and the negative lead of the power
supply to the negative (black) lead of the
brake.
2. Connect a volt-meter to measure the voltage
applied across the brake.
3. Adjust the power supply to its lowest
possible output, then energize the power
supply only, to apply power to the brake.
4. Starting from the low point, slowly increase
the applied voltage until the brake armature
disengages from the magnet. Note and
record the applied voltage at this point.
5. Continue to slowly increase the applied
voltage until the armature re-engages the
magnet. If the maximum voltage available
from the supply does not cause the armature
to re-engage, the armature should be
manually assisted into engagement.
Note: If armature needs to be manually
assisted, armature should be pressed on
back side to make contact with friction
face of magnet.