Warner Electric Electro-Brake 375, 475, 650, 825, 1000, 1225 - Manual (Page 6)

6 Warner Electric • 800-825-9050 P-211 • 819-0043
Burnishing and Maintenance
Burnishing
Intimate metal to metal contact is essential
between the armature and the metal rings
(poles) of the magnet or rotor. Warner Electric
clutches and brakes leave the factory with the
friction material slightly undercut to assure good
initial contact.
Normally, the desired wearing-in process occurs
naturally as the surfaces slip upon engagement.
The time for wear-in, which is necessary to
obtain the ultimate torque of the unit, will vary
depending on speed, load, or cycle duty.
If maximum torque is required immediately after
installation, the unit should be burnished by
slipping the friction surfaces together at reduced
voltage. It is recommended that the burnishings
be done right on the application, if at all
possible.
Burnishing at high speed will result in a
smoother wear-in pattern and reduce the time
for burnishing. The voltage should be set at
approximately 30% or 40% of the rated value.
The unit should be cycled on and off to allow
sufficient time between slip cycles to prevent
overheating.
When a Warner Electric brake or clutch is
properly assembled and installed, no further
servicing, lubrication, or maintenance should be
required throughout the life of the unit.
Maintenance
Wear Pattern: Wear grooves appear on the
armature and magnet surfaces. This is a normal
wear condition, and does not impair functioning
of the unit. Normally, the magnet and armature,
as a mating pair, will wear at the same rate. It is
the usual recommendation that both
components be replaced at the same time.
Re-machining the face of a worn armature is not
recommended. If a replacement armature is to
be used with a used magnet, it is necessary to
re-machine the worn magnet face. In refacing a
magnet: (1) machine only enough material to
clean up the complete face of the magnet;
(2) hold the face within .005" of parallel with the
mounting plate; and (3) undercut the molded
facing material .001" - .003" below the metal
poles.
Heat: Excessive heat and high operating
temperatures are causes of rapid wear. Units,
therefore, should be ventilated as efficiently as
possible, especially if the application requires
fast, repetitive cycle operation.
Foreign Materials: If units are used on
machinery where fine, abrasive dust, chips or
grit are dispelled into the atmosphere, shielding
of the brake may be necessary if maximum life
is to be obtained.
Where units are used near gear boxes 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 further torque
loss.
Torque Loss: If a brake or clutch slips or loses
torque completely, the initial check should be
the input voltage to the magnet as follows:
90-Volt Series: Connect a DC voltmeter with a
range of 0-100 or more directly across the
magnet terminals. With the power on and the