General Trouble Shooting
P-233
819-0451
Failure to follow these
instructions may result in product damage,
equipment damage, and serious or fatal
injury to personnel.
Contents
Electrical Troubleshooting . . . . . . . . . . . . . . . . . . . . . 2
Clutch and Brake . . . . . . . . . . . . . . . . . . . . . . . . . 2
Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Mechanical Troubleshooting
Autogap Installation . . . . . . . . . . . . . . . . . . . . . . . 4
Safety Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Taper Bushings. . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Brushholder Mounting . . . . . . . . . . . . . . . . . . . . . 5
Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Armature Flatness. . . . . . . . . . . . . . . . . . . . . . . . . 5
Environmental Problems
Oil, Grease, Dirt, Chips, Abrasive Grit . . . . . . . . . . 6
Wear Pattern
Burnishing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Wear Life
Heat Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . back cover
General Troubleshooting For All Units
The Service Manuals listed below are available
without charge. When ordering, specify form
number of desired publication.
Form Description
Number
P-200 Service Manual: SF-120, 170;
SFC-120, 170; PB-120, 170;
SF-250, 400; SFC-250, 400.
P-201 Service Manual: PB-250, 400.
P-202 Service Manual: SF-500, 650; SFC-
500, 650; SPBC-500, 650.
P-203 Service Manual: PC-500; PCC-500,
PCBC-500.
P-204 Service Manual: PB-500, 650.
Installation Instructions
P-205 Service Manual: PCB-825, 1000,
1225; PCBC-825, 1000, 1225.
P-206 Service Manual: PC-825, 1000, 1225,
1525; PCC-825, 1000, 1225, 1525.
P-207 Service Manual: SFC-825, 1000, 1225,
1525; SFC-1525, Hi-Torque
P-208 Service Manual: PB-825, 1000, 1225,
1525; MB-825, 1000, 1225.
P-209 Service Manual: PB-825, 1000, 1225,
1525.
P-210 Service Manual: EC-375, 475, 650,
825, 1000, 1225.
P-211 Service Manual: EB-375, 475, 650,
825, 1000, 1225.
P-212 Service Manual: EP-170, 250, 400,
500, 825, 1000, 1525.
P-213 Service Manual: EM-50-10, 180-10,
210-10; EM-50-20, 180-20,
210-20; EM-50-30, 180-30, 210-30;
EM-50-40, 180-40, 210-40.
P-214 Service Manual: PCBC-1225/1000,
1525/1225; PCB-1225/1000,
1525/1225.
P-215 Service Manual: SF-825, 1000, 1225,
1525; SF-1525 Hi-Torque
P-220 Service Manual: Controls
P-231 Service Manual: Electro-Disc
P-235 Tension Control System
P-237 Service Manual: Electrically Released
FB-375, 475, 650.
P-238 Installation Manual: Motion Control
P-239 Installation Manual: Power-Supplies
P-248 Technical Manual: W-Line
P-250 Service Manual: ER-825 & 1225 Pin
Drive
P-251 Service Manual: ER-825 & 1225 Spline
Drive
P-252 Service Manual: MCS-129, 129-1
P-256 Service Manual: Modular Tension
Brake
Electrical Troubleshooting
Coil Data
Unit Size SF/PB 120 SF/PB 170 SF/PB 250
Voltage – DC 6 24 90 6 24 90 6 24 90
Resistance @ 20°C – Ohms 6.32 104 1386 6.96 111.2 1506 5 76.4 1079
Current – Amperes .949 .230 .065 .861 .215 .060 1.2 .314 .084
Watts 5.69 5.52 5.85 5.85 5.16 5.37 7.2 7.5 7.51
Coil Build-up – milliseconds 12 12 11 17 17 16 48 48 44
Coil Decay – milliseconds 887 8 7 6 15 15 13
Unit Size SF/PB 400 SF-500 PB & PC 500 SF-650
Voltage – DC 6 24 90 6 24 90 6 24 90 6 24 90
Resistance @ 20°C – Ohms 4.88 73 1087 1.076 14.9 206.1 1.36 23.8 251.1 1.16 17.7 225
Current – Amperes 1.23 .322 .083 5.58 1.61 .44 4.4 1.01 .36 5.19 1.36 .4
Watts 7.39 7.96 7.45 34 39 39 26 24 32 31 33 36
Coil Build-up – milliseconds 154 154 154 82 85 90 84 87 93 110 115 120
Coil Decay – milliseconds 62 60 55 40 40 40 38 35 30 50 50 50
Unit Size PB-650 SF-825 SF-825 Brg PB & PC 825 SF-1000 PB & PC 1000
Voltage – DC 6 24 90 6 24 90 6 24 90 6 24 90 6 24 90 6 24 90
Resistance @ 20°C – Ohms 1.24 18.3 257.2 1.23 20.9 267.0 1.098 14.6 221 1.27 20.4 223.3 1.07 14.4 214.4 1.23 19.7 248.7
Current – Amperes 4.84 1.31 .35 4.9 1.15 .34 5.464 1.65 .407 4.74 1.18 .4 5.61 1.67 .42 4.87 1.22 .36
Watts 29 31 32 29 28 30 33 40 37 28 28 36 34 40 38 29 29 33
Coil Build-up – milliseconds 100 105 110 222 200 245 180 200 225 170 170 170 256 275 283 205 220 235
Coil Decay – milliseconds 50 50 50 105 120 100 115 120 130 70 75 80 123 105 90 70 75 80
Unit Size SF-1225 PB & PC 1225 SF-1525 PB & PC 1525 SF-1525 H.T.
Voltage – DC 6 24 90 6 24 90 6 24 90 6 24 90 6 90
Resistance @ 20°C – Ohms 1.21 19.5 268.3 1.33 22.3 261.7 1.11 15.5 239.1 1.45 19.8 258.4 55 113.4
Current – Amperes 4.97 1.23 .34 4.5 1.08 .34 5.41 1.55 .38 4.13 1.21 .35 10.83 .794
Voltage Check
The initial electrical check should be the input
voltage to the magnet, as follows:
For 90 volt units connect a DC voltmeter with a
range of 0-100, or more, directly across the
magnet terminals. With the power on the
potentiometer turned up, a normal reading is 90
volts, although 85 to 105 is satisfactory. The
reading should drop smoothly as the
potentiometer is turned counterclockwise.
For 6 volt magnets use a DC range on the
voltmeter of approximately 0-15 volts. A normal
reading is from 5.5 to 6.5 volts, depending on
the power supply.
Current Check
A low range ammeter, when connected in series
with one magnet lead, will normally indicate
approximately .35 amperes for the 90 volt IHP
units and 4.0 amperes for the 6 volt series. These
readings are with power on and the potentiometer
control in the maximum position.
Resistance Check
Ohmmeter checks should be made with the
power off and the circuit open (to be certain,
disconnect one magnet lead). Average resistance
for the IHP 90 volt series is 250 ohms; for the 6
volt series, 1.5 ohms. A very high or infinite
resistance reading would indicate an open coil.
Summary
If the above checks indicate that the proper
voltage and current is being supplied to the
magnet, mechanical parts should be checked to
assure that they are in good operating condition
and properly installed.
Warner Electric • 800-825-9050 P-233 • 819-0451
2
Note: The following steps apply to the basic
standard controls.
General
1. Make a visual check from the control input to
the clutch or brake units, looking for frayed
wires, broken wires, or loose connections.
Examine the lead wires or terminals at the
clutch or brake. Look for dirt, grease, or metal
chips that would interfere with a good electrical
circuit. Make a special check at the
brushholder when a PC clutch is involved.
Problems may result from a loose brushholder,
worn-out brushes, or a loose terminal
connection caused by steady machine
vibration or simply a broken wire.
A current check is usually not necessary
although one can be made by placing an
ammeter in series with the clutch or brake
coil. Correct readings are listed in the coil
data chart on page 4.
Voltage Control
4. Check the potentiometer or rheostat settings.
Frequently an operator will change the original
settings thinking that this will improve the
performance of the machine. The
potentiometer or rheostat should be set at a
voltage level no lower than necessary to
achieve satisfactory operation. Since
conditions vary from one application to
another the setting must be determined
through trial and error.
To determine if a potentiometer or rheostat is
working properly, measure the resistance with
the power off. A smooth variation in
resistance should be noted from a minimum
of 0 to approximately 1000 ohms.
If the voltage settings are correct and the
control still does not function, check the input
to the control.
Fuse
2. Check the fuse. The fuse is a glass cartridge
type and can be checked visually. Make certain
that the fuse is of the proper value.
Output
3. With a DC voltmeter, check the output of the
control at the clutch and brake (potentiometer
or rheostats should be at maximum). With the
coil connected, a normal reading is 85-105
volts DC. If the output is normal and the unit
still does not function, check the clutch and
brake coils against the nominal readings in the
coil data chart on page 4.
When checking resistance, make sure the
power is off. Disconnect one lead to be certain.
A shorted coil will indicate a zero resistance,
while an open coil will read infinity.
Input
5. Place an AC voltmeter across the AC input
connections to the control (connections are
shown on each drawing). The AC supply
voltage should be within ±5% of the nominal
rating. Example: for a 115 volt AC input the
acceptable range is from approximately 110
to 120 volts.
When using a control with a transformer, the
AC voltage must be checked both at the
input (transformer primary) and the output
(transformer secondary). The output should
be approximately 115 volts AC regardless of
whether the input is 230, 460, or 575
volts AC.
If the readings are normal, the switching
should be checked next.
Warner Electric • 800-825-9050 P-233 • 819-0451
3