Warner Electric Electro-Module EM-50, EM-100, EM-180, EM-210, EM-215 - Manual (Page 10)

10 Warner Electric • 800-825-9050 P-213 • 819-0303
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
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, a screen over the ventilation
holes may be necessary.
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 effec-
tive. 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 module slips or loses torque
completely, the initial check should be the input
voltage to the magnet or field as follows:
90-Volt Series: Connect a DC voltmeter with a
range of 0-100 or more directly across the mag-
net or field 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 con-
trol is adjusted counter-clockwise.
24 Volt Series: Use a DC voltmeter of approxi-
mately 0-40 volt range. A normal reading is from
23 to 25 volts.
6-Volt Series: Use a DC voltmeter of approxi-
mately 0-15 volt range. A normal reading is from
5.5 to 6.5 volts depending on the power supply.
The above checks normally are sufficient.
Further checks may be made as follows: a low
range ammeter, when connected in series with
one magnet lead, will indicate amperes as
shown in chart on page 8. These readings are
with the power on and the potentiometer control
in the maximum position.
Ohmmeter checks should be made with the
power off and the circuit open (to be certain,
disconnect one lead to the magnet). A very high
or infinite resistance reading would indicate an
open coil.
If the above checks indicate that the proper
voltage and current is being supplied to the coil
mechanical parts should be checked to assure
that they are in good operating condition and
properly installed.