Warner Electric Electro-Packs EP-170, 250, 400, 500, 825, 1000, 1525 - Manual (Page 7)

7 Warner Electric • 800-825-9050 P-212 • 819-0078
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
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 counterclockwise.
24-Volt Series: Use a DC voltmeter with a
range of 0-30 volts or more. A normal reading
is approximately 22-26 volts.
6-Volt Series: Use a DC voltmeter of
approximately 0-15 volt range. A normal
reading is from 5.5 to 6.5 volts.
The above checks normally are sufficient.
Further checks may be necessary, such as
voltage, amperage and resistance. Refer to chart
on following page for electrical readings on the
clutch / brake you are measuring. Observe all
safety procedures and test equipment
manufacturers operating procedures. The
voltage and amperage measurements are
made with the power on and the control at full
output. Resistance measurements are made with
power off and clutch / brake disconnected from
control, measuring only the clutch coil or the
brake magnet. Resistance measurements should
be + / - 10% of values on chart.
If the above checks indicate that the proper
voltage and current is being supplied to the
clutch and brake, mechanical parts should be
checked to assure that they are in good
operating condition and properly installed.