Warner Electric Performance Plus Preassembled Clutch_Brake Module - Manual (Page 6)

6 Warner Electric • 800-234-3369 P-273-3 • 819-0358
The minimum pitch diameter pulley or sprocket
that can be used, for satisfactory bearing life, is
determined from the formula:
Min. P.D. = 2 T K
R
T - Torque (in.lbs.). This is the torque actually
being transmitted, not necessarily the maximum
torque capacity of the Electro-Module.
Torque = 63025 x HP
RPM
K - The safety factor for the tension in the type
of drive.
Use: 1 for chain and sprocket
1 for timing belt
2 for V-belt
3 for flat belt
R - Radial load allowable (values at various dis-
tance from the housing face are given in the
chart).
Example: What is the minimum V-belt pulley
that can be applied to the center of the shaft
of an EM-50 module. The torque requirements
is 112 in. lbs.
Min. P.D. = 2 x 112 x 2 = 2" minimum P.D. pulley
224
Burnishing
The ceramic faced friction surfaces of these
Unimodules are pre- burnished and perform-
ance tested at the factory to ensure consistent
"out of box" performance. Therefore, no "wear-
ing in," or burnishing, is required. Full rated per-
formance should be achieved after running for a
few cycles, usually fewer than 50.
Maintenance
Wear Pattern
Wear grooves appear on the friction
surfaces.This is a normal wear condition, and
does not impair functioning of the unit. Never
machine the friction surfaces to remove grooves
or score marks resulting from normal wear.
Heat
Excessive heat and high operating temperatures
can cause premature bearing failure. Units,
therefore, should be ventilated as efficiently as
possible, especially if the application requires
fast, repetitive cycle operation.
Foreign Materials
When units are used near gear boxes or trans-
missions requiring frequent lubrication, means
must be provided to protect the friction surfaces
from oil and grease to prevent serious torque
loss.
Troubleshooting
With the motor at rest and locked out, check the
following:
A. With power off to the clutch and brake, spin
the output shaft by hand. It should turn with
only the light drag of the preloaded arma-
tures.
B. If a brake or clutch slips or loses torque com-
pletely, the initial check should be the input
voltage to the magnet or field as follows:
90-Volt: Connect a DC voltmeter with a range
of 0-100 volt directly across the magnet or
field terminals. With the power on and the
torque control potentiometer turned up, a
normal reading is 90 volts, although 85 to 95
is satisfactory. The reading should drop as
the potentiometer control is adjusted coun-
terclockwise.
24 Volt: Use a DC voltmeter with a range of
0-30 volts or more. A normal reading is
approximately 22-26 volts, depending on the
power supply.