Rockwell Automation 56 User manual

Installation, Operation
and Maintenance Manual
Small DC Motors
• 56 Frames

2Small DC Motors
Receiving and Handling
Acceptance
Unpack motor carefully and inspect for possible damage during shipment.
Check packing materials and save any instruction tags or wiring diagrams
found in the carton. Report any damages or shortages immediately to the
local transportation agent.
Installation Mounting
Check nameplate data on motor before installing to assure the correct rating
and that the available power supply agrees with the required motor power
supply. Motor should be mounted on a firm foundation. If the foundation is
not flat, use shims to prevent misalignment when tightening hold-down
bolts. DC motors arc equipped with ball bearings and may be operated in
any position. For any position other than base down, new drain holes should
be provided so that condensation is allowed to run off. Location should be
dry, clean and well ventilated for most satisfactory service. Be sure the
possibility of oil seepage into the motor is prevented. Commutator end of
the motor should be accessible so that brushes can be conveniently
inspected.
Mounting Instructions for 56C & 140TC Face Mounted Motors
Before mounting a “C” face motor to a mating flange, be sure both surfaces
and all mounting holes are smooth and free of debris.
When mounting into a quill type reducer, make sure the input and output
shafts are coated with an anti-seize compound suitable for the application.
!ATTENTION: Only qualified electrical personnel familiar with
the construction and operation of this equipment and the hazards
involved should install, adjust, operate, and/or service this motor.
Read and understand this manual in its entirety before
proceeding. Failure to observe this precaution could result in
personal injury or loss of life.
!ATTENTION: High voltage and rotating parts can cause serious
or fatal injury. The use of electric machinery, like all other
utilization of concentrated power and rotating equipment, can be
hazardous. Installation, operation, and maintenance of electric
machinery should be performed by qualified personnel.
Familiarization with NEMA safety standards, national electrical
code and sound local practices is recommended.
!ATTENTION: To guard against personal injury or death caused
by contact with moving parts, guards (coupling, belt, chain, etc.)
must be installed. Machines accessible to the public should be
further guarded by screening, guard rails, etc.

Small DC Motors 3
When mounting through a flexible coupling, verify that there is adequate
clearance between the driven equipment shaft, the coupling interface and
the motor shaft. Lack of clearance may result in binding of the shafting and
premature bearing failure.
Always slide the motor tenon into the mating flange to its full depth before
tightening the mounting bolts. Do not allow the motor to hang by the shaft
extension while assembling it to the driven equipment (i.e. quill input gear
case). This may bend or crease the shaft and damage any seals that are
present.
Only use the proper mounting bolts. These should be 3/8”-16 threads per
inch and sized for length such that engagement into the motor flange does
not exceed 9/16”. For example, a gear case with a 3/8” flange thickness
requires a bolt that is: 3/8” + 9/16” = 15/16” = Maximum Bolt Length
Since 15/16” is not a standard bolt length, a 7/8” bolt or a 1” bolt with a
lockwasher can be used.
Alignment
Shafts should be carefully aligned before tightening any couplings. Inspect
couplings and shaft for paint, dirt or burrs. If necessary, remove with
sandpaper for proper fit. Pulley or coupling should be carefully fitted. Do
not hammer on shaft, pulley or coupling.
Application
Permanent Magnet “PM” motors are not always designed for across the line
starting. This may cause loss of flux resulting in an increase in speed and
possibly instability. Wound field motors can be started across the line with
full applied voltage. However, for frequent starting or reversing, voltage
should be reduced for normal brush and commutator life.
Dynamic or regenerative braking methods should not be used unless
provisions are made to limit the maximum instantaneous current to a value
not greater than the maximum allowable peak amperes shown on the
nameplate. This also applies to plug reversing the PM motor.
Connections
All motors should be installed in accordance with the National Electric
Code and local requirements. Fuses, thermal cutouts and other protective
devices should be the proper size and rating to safely carry the load and to
interrupt the circuit on overloads.
!ATTENTION: To guard against motor damage such as
premature failure and/or a loose assembly, use only mounting
bolts that are the correct length. A bolt that is too long may cause
damage to the motor.

4Small DC Motors
Connection diagrams are shown above. Care must be taken to ensure that
the dual-voltage shunt field is properly connected.
Some DC motors are equipped with a thermostat inside the motor. This
thermostat has a normally closed (NC) contact which opens if the motor
temperature exceeds design limits due to extended overload operation.
Leads from the thermostat are labeled P1 & P2and should be connected in
series with the drive “STOP” button (refer to the previous figure).
!ATTENTION: Ground the machine properly to avoid serious
injury to personnel. Grounding should be in accordance with the
National Electrical Code and consistent with sound local
practices.
+A1
High
Voltage
Connection
1, 2
Low
Voltage
Connection
1, 2
High
Voltage
Connection
1, 2
Low
Voltage
Connection
1, 2
Permanent
Magnet
Thermostat
(if furnished)
Ground
Connection
Connect in Series
with Control Stop
Device
Earth Ground
Series
A2
S1
+F1
F11
F2
A1
+A2
S1
+F1
F11
F2
+A1
A2
S1
–S2
+F1
F11
F2
A1
+A2
S1
+F1
F11
F2
S2 F22 S2 F22
F22 –S2 F22
+A1
Type
ShuntStabilized Shunt and Compound
CCW
Rotation Facing Commutator End
CW
–A2
+F1
F11
–F2
+A1
A2
S1
S2
A1
+A2
S1
S2
F22
+A1
–A2
–A1
–A1
+A2
+F1
F11
–F2
F22
+A1
A2
+F1
F11
F2
F22
–A1
+A2
+F1
F11
F2
F22
+A2
P1
P2
1 Motors with single voltage fields do not have leads F11 & F22. Leads F11 & F22 may be
marked F3 & F4, respectively. Connect on low voltage field connection.
2 Consult motor nameplate to determine value of low and high voltage connection.

Small DC Motors 5
Important:When motors are provided with thermal protection (typically
thermostats), it is important to properly connect and apply the
devices. This will ensure that the motor is properly protected
from being operated if thermal limits are reached and/or
exceeded. The control system must be configured to reduce the
motor load and/or shut down the motor control system to allow
the motor to cool to a level within acceptable operating ranges.
If the motor is operated with the thermal protective devices
tripped (indicating an over temperature condition), the motor
insulation could be damaged and complete failure of the motor
insulation is possible. In the event of motor failure due to an
over temperature condition, Rockwell Automation requires that
motor thermal protective devices (when supplied) be
adequately monitored and incorporated into the motor control
system to maintain warranty. Failure on the part of the
individual installing this equipment to take these steps will
result in the factory warranty being voided.
Operation
These motors are inherently capable of operating over a wide range of
speeds and loads. If the motor is not operated on the type of power supply
for which it was designed, performance will differ from nameplate values
and applicable standards.
The motor should start quickly. If it fails to start, the load may be too great,
the applied voltage too low, or the motor improperly connected and/or the
control misadjusted (check particularly current (torque) limit adjustment).
In any case, immediately disconnect the power and investigate the cause.
While operating the motor, observe the performance. Any undue noise,
overheating, sparking or erratic performance should be investigated and
necessary corrective action taken to prevent serious damage.
Maintenance The fundamental principle of electrical maintenance is keep the apparatus
clean and dry. This requires periodic inspection of the motor, the frequency
of inspection depending upon the type of motor and the service.
!ATTENTION: Internal parts of this motor may be at line
voltage even when motor is not rotating. Disconnect all AC line
connections before contacting any internal part.

6Small DC Motors
Bearings
Ball bearings are deep grooved, double shielded with sufficient lubricant
packed into the bearings by the manufacturer for “life lubrication.” The
initial lubricant is supplemented by a supply packed into larger reservoirs in
the end shield at time of assembly. No grease fittings are provided. The
initial lubrication is adequate for up to 5 years of operation under normal
conditions.
Should it become necessary to replace bearings, the bearing bore and cavity
should be thoroughly cleaned and repacked with approximately 1/2
teaspoonful of recommended grease.
Bearings should be removed with bearing pullers using a center insert in the
end of the shaft to protect the shaft center. To reinstall ball bearings, either
in a press or on the bench, pressure should be applied to the inner race by
using a square faced sleeve or piece of pipe that will fit over the shaft, to
avoid damaging the bearing. If a press is not available and a hammer is
used, the blows should be transmitted against the sleeve by a block of wood
or fiber.
Brushes
Check brushes to make certain that they move freely in the holders and
make proper contact with the commutator. Re-place worn brushes. Give
complete motor identification when ordering parts. New brushes should be
pre-radiused to fit the commutator curvature. Blow out the carbon dust.
Short brush life and poor commutation may be due to a rough commutator,
a shorted armature, or poor undercutting of mica. Dirt and chemicals in the
air are common causes of trouble.
Commutator
The commutator should remain a polished surface. Blackening may indicate
rough or eccentric commutator. Occasional wiping (power off) with dry
canvas or non-linting cloth may suffice. If rough or excessively dirty,
smooth with very fine (00) sandpaper lightly with armature rotating. Never
use emery cloth. Never allow the brushes to wear so short that spring
tension is lost. The resultant sparking will seriously damage the
commutator.
If frequent dressing is required, the cause should be found and corrected. A
very rough commutator should be turned in a lathe, at high speed, with a
sharp tool. Do not remove more copper than necessary. The mica should be
undercut if necessary.
An authorized service shop is recommended for this work.

Small DC Motors 7
General
The following should be checked at regular intervals:
•Windings should be dry and free of dust, grease, oil, and dirt. Windings
may be cleaned by suction cleaners or by wiping. Nozzles on suction
type cleaners should be non-metallic. Gummy deposits of dirt and grease
may be removed by using a commercially available low volatile solvent.
Do not use gasoline or other inflammable solvents.
•Terminal connections, assembly screws, bolts and nuts should be tight.
They may loosen if motor is not securely bolted and tends to vibrate.
•Insulation resistance of motors in service should be checked periodically
at approximately the same temperature and humidity conditions to
determine possible deterioration of the insulation. When such
measurements at regular intervals indicate a wide variation, the cause
should be determined. Motor should be reconditioned if the motor has
been subjected to excessive moisture, or by rewinding or reinsulating if
necessary. Enclosed motors require very little attention. Be sure that
external air chamber of fan cooled motors does not become clogged with
foreign material which will restrict passage of air.
Troubleshooting If trouble develops in operation of motor, verify that:
1. The bearings are in normal condition and have been properly lubricated
with a high grade, ball bearing lubricant, free of dirt or grit. If dirt enters
bearing, flush and relubricate.
2. There is no mechanical misadjustment to prevent free rotation of moving
parts of motor and drive.
3. All bolts and nuts are properly tightened.
4. Motor instructions have been carefully carried out.
5. The rated voltage is available at the motor terminals.
6. The voltage corresponds to the value stamped on the nameplate.
7. All connections are properly made in all circuits between motor and
control.
8. The overload and low voltage devices in control equipment, fuses or
other protective devices are in proper working order.
9. Brushes are in good condition and are making good con-tact with the
commutator.
10.The commutator is clean and has smooth polished surface.
11.No excessive overload exists on the motor. Compare line amperes at full
load with nameplate stamping.
!ATTENTION: Internal parts of this motor may be at line
voltage even when motor is not rotating. Disconnect all AC line
connections before contacting any internal part.

Online Documentation
The latest motor information can be obtained from the Allen-Bradley
Drives & Motors home page on the World Wide Web at:
http://www.controlmatched.com
Publication 1325R-UM001B-EN-P Ð August, 2001
Supersedes 1325R-UM001A-EN-P dated May, 2001 Copyright © 2001 Rockwell Automation. All rights reserved. Printed in USA.