GE GEH-5304A User Manual
GE Industrial Systems
Instructions
Direct Current Motors & Generators
GEH-5304A
Type CD
Frames 2512AT, 2513AT
Frames 2812AT, 2813AT
GEH-5304A
These instructions do not purport to cover all of the details or variations in equipment nor to provide for every possible
contingency to be met in connection with installation, operation, or maintenance. Should further information be desired
or should particular problems arise which are not covered sufficiently for the purchaser’s purposes, the matter should be
referred to the General Electric Company.
© Copyright 1985, 1992, 1999 Gener a l El ectri c Company
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GEH-5304A
Table of Contents
Subject Page
Introductio n..............................................................................................................................5
Receiving..................................................................................................................................5
Storage ............................................................................................................................5
Handling ..........................................................................................................................6
Installation................................................................................................................................7
Location...........................................................................................................................7
Mounting .........................................................................................................................8
Alignment ........................................................................................................................8
Coupled Drive.........................................................................................................8
Alignment Procedure-Flexible Coupling, Non-Self-Supporting Bases..............8
Alignment Procedure-Flexible Couplings, Self-Supporting Bases.....................9
Grouting..................................................................................................................9
V-Belt Drives ..........................................................................................................9
Bearing Life.............................................................................................................9
Special Load Considerations..................................................................................11
Pinion Drives.........................................................................................................11
Thrust Loads.........................................................................................................11
Operation ................................................................................................................................11
Inspection Before Starting..............................................................................................12
Bearings and Couplings.........................................................................................12
Commutator and Brushes.......................................................................................12
Rectified Power Supplies.......................................................................................12
Power Supply Identificaiton ...................................................................................14
Connections...................................................................................................................15
Protective Devices..........................................................................................................15
Motor Field Heating.......................................................................................................15
Thermostats ...................................................................................................................15
Speed Limit Devic e ........................................................................................................16
Space Heater..................................................................................................................16
Ventilation System.........................................................................................................17
General Mechanical Inspection.......................................................................................17
Accessory Mounting ......................................................................................................18
Brakes............................................................................................................................18
Inspection After Starting................................................................................................18
Bearings................................................................................................................18
Noise and Vibration...............................................................................................19
Inspection After Short Time In Service..................................................................19
Maintenance............................................................................................................................19
Disassembly ...................................................................................................................20
Reassembly....................................................................................................................20
Bearings......................................................................................................................... 21
Replacement of Bearings................................................................................................ 21
3
GEH-5304A
Subject Page
Brushes..........................................................................................................................22
Brush Removal With Machines Stopped and Power Off.........................................22
Brush Installation...................................................................................................23
Commutator...................................................................................................................24
Mechanical.....................................................................................................................25
Shaft End Play................................................................................................................25
Waterproof Machines.....................................................................................................25
Lubrication of Flexible Couplings ...................................................................................25
Insulation.......................................................................................................................25
Testing Methods ............................................................................................................26
Visual Inspectio n...................................................................................................26
Insulation Resistance Measurement........................................................................26
Cleaning of Windings ....................................................................................................27
Oily Dirt................................................................................................................28
Drying of Windings........................................................................................................29
Service Shop Cleaning....................................................................................................29
Repair ............................................................................................................................29
Renewal Parts.........................................................................................................................30
Storage of Renewal Parts ...............................................................................................30
Commutator Check Chart.......................................................................................................32
4
Direct Current Motors and Generators
Type CD
Frames 2512AT, 2513AT, 2812AT, 2813AT
I. INTRODUCTION
This in struction book c ove rs the CD2512AT-CD2813AT line of DC motors and generators.
High voltage and rotating parts can cause serious or fatal injury. The use of
electric machi nery, like all oth er utilization of concentrated power and rotating
equipment, can be hazardous. Installation, operation and maintenance of electric machin ery should be performed by qualified personnel. Familiarization with
NEMA Safety Standard for Construction and Guide for Selection, Installation
and
Use of Integral HP Motors and Generators, National Electrical Code and sound local practices is
recommended.
These instruction s do not purport to cover all details or variations in equipment nor to provide for every possible
contingency or hazard to be met in connection with installation, operation and maintenan ce. Should further infor-
mation be desired or should particular problems arise wh ich are not covered sufficiently for the purchaser’s purposes, the matter should be referred to GE Industrial Systems.
GEH-5304A
II. RECEIVING
The equipment should be placed under adequate cover immediately upon receipt, as packin g covering s are NOT
suitable for out-of-doors or unprotected storage.
Each shipment should be carefully examined upon arrival. Any damage should be reported promptly to the carrier
and to the nearest office of GE Industrial Systems.
A. Storage
During installation or when in storage, the machine and its parts must be protected fr om the following:
1. Dirt of all kinds.
2. Wetness and temperature extremes.
Protection from dirt can be achieved by covering the machine with a tarpaulin or polyethylene sheet or
keeping it in a clean area.
Protection from wetness and temperature extremes includes moisture from the surrounding atmosphere condensing onto cooler machine surfaces. This condensation on machine surfaces can result in rusting or corrosion and the electrical windings may suffer serious damage.
Where wetness and/or cold conditions are present, the machine and its parts must be protected by a safe reliable heating system which, at all times, will keep the machine temperature slightly above t hat of the su rrounding atmosphere. If a space heater is included in the machine, it should be energized.
Smaller machines shipped in paper cartons are protected from condensing-type wetness by the insulating
characteristics of the carton. To avoid sweating where these have been exposed to low temperature for an
extended period, allow the machine and carton to attain room temperature before unpacking.
5
GEH-5304A
Brushes should not remain in contact with the commutator during prolonged storage because corrosion may
occur and later result in flat spots on the commutator . Release the brush springs and lift the brushes when
stored for a period of more than six months.
All exposed machined steel parts are slushed with a rust preventative before shipment. These surfaces
should be examined carefully for signs of rust and moisture, and reslushed if necessary. Once start ed, rust
will con tinue if the surface is reslushed with out first removing all rust and moisture. Rust may be removed
by careful use of fine abrasive paper. Slushing compound can be removed by use of a suitable solvent such
as mineral spirits.
Mineral spirits are flammable and moderately toxi c. The usual precau tions for
handling chemicals of this type must be observed. These in clude:
1. Avoid excessive contact wi t h skin.
2. Use in well ven t ilated areas.
3. Take necessary precautions to prevent fire or explosion hazards.
Extreme care must be exercised in removing rust on shaft extensions near shaft seals, since it is difficult, and
sometimes impossible, to remove rust from these surfaces without damaging or deforming them.
Burrs or bumps on other machined surfaces should be carefully removed by using a fine file or scraper.
Machines in storage should be inspected, have the insulation resistance checked at fr equent and regular intervals (refer t o Insulation Resistance section), and a log kept of pertinent data.
When stored, it is suggested that the armature be rotated every t hree mo nth s to
prevent loss of grease protection on the bearings and races. Loss of grease
protection causes rust.
B. Handling
Complete motors or generators can be lifted by using hooks or slings in the lifting lugs of the unit. The lifting lugs are designed to safely carry the weight of the individual machine. DO NOT
the shaft extensions.
lift the machine with
Motor generator sets or units with heavy attachments such as gear boxes or
pumps must not be lifted by using the lifting lugs of the individual machines.
Motor generator set bases have lifting holes, to be used with spreader bars or hooks. Care must be taken in
handling to avoid twisting bases.
6
Table 1
Typical Weights**
Motor (Less
Accessories) Armature
CD2512AT 500 120
CD2513AT 550 135
CD2812AT 650 160
CD2813AT 750 190
**Typical weights. For speci fic weight, see certi fied outline.
III. INSTALLATION
Installation should be in accordance with the Nation al Electrical Code and consistent with all local codes. Coupling, belt and chain guards should be installed as needed to pr otect against accidental contact with moving parts.
Machines accessible to the public should be further guarded by screening, guard rails, etc. to prevent personnel
from coming in contact with the equipment. Fully guarded covers are supplied on motors and generators. Shaft
guards are supplied on motor generator sets.
Totally enclosed and waterproof motor s must have all covers securely in place with gaskets intact in order to exclude dirt, oil and water. It is generally preferred to r emove plugs from drain holes at the bottom of the frame to
ensure that no condensation will collect inside the motor . However, if the installation requires plugs to be installed,
they must be removed periodically to make certain that all water is eliminated.
GEH-5304A
A. Location
Motors and generators should be installed so that they will be readily accessible for routine inspection and
maintenance. They are suitable for use in ambient temperatures fr om 0°C (32°F) to 40°C (104°F). An adequate supply of clean, dry room air is required for self-ventilated, separately ventilated and blown motors.
Where motors must operate in dirty, wet or contaminated environments, protection in the form of filters or
totally enclosed construction must be used to obtain long life with normal maintenance.
Do not obstruct ventilating openings.
When filters are supplied, service them regularly. Dirty filters shut off ventilating air .
Bewar e of recirculation. Install motors so that hot exhaust air will not re-enter the motor.
The use of electrical equipment in hazardous locations is restricted by the National Electrical Code, Article 500. Original equipment manufacturers and user
customers must read, understand and apply these rules for installation and use
of all equipment in such locations and consult local code inspection and en-
forcement agencies, as necessary, to ensure compliance. Motors listed by
Underwriters Laboratories, Inc. for use in specific locations have been designed, tested and approved for use in such locations only.
Sections 501-8 and 502-8 now permi t the use of tot ally enclo sed motors with positive pressure
ventilation or totally enclosed inert-gas-filled motors (Class I locations only), when installation
and operat ion conform to certain requ irements.
Motors for Class I locations must have leads sealed at the frame exit and an explosion-proof
conduit box. See Sections 501-4 and 501-5.
Motors for Class II locations must have leads sealed at the frame exit an d a dust-ignition-proof
conduit box. See Sections 502-4 and 502-5.
7
B. Mounting
Motors and generators should be mounted on rigid and solid foun dations. Level the base (or the machine).
Hold-down bolts should be inspected regularly and kept tight. The feet of the machin e may be doweled to
the foundation plates or base when alignment procedures are completed. Sliding bases, when used, should
be securely anchored to the foundation.
Motors are mechanically suitable for mounting with shaft horizontal or vertical on floor, ceiling or sidewall.
When sidewall or ceiling mounted, special provisions must be made to maintain the integrity of dripproof
enclosu res.
When motor is sidewall or ceiling mounted, lifting points in addition to the
standard lifting lugs may be required. Lifting, in these cases should be done by
experienced riggers to avoid injury to personnel and damage to the moto r.
C. Alignment
Be sure to align or check alignment carefully on either motors or motor genera-
tor sets. Misalignment can cause excessive vibration and damaging forces on
shafts and bearings.
GEH-5304A
Time taken to assure good alignment will be returned in reduced downtime.
1. Coupled Dr ive
When a motor is used to dr ive a unit, flexible couplings must be used to facilitate alignment. Threebearing construction requir es a r i gid coupling.
Careful alignment of machines when using either solid (rigid) or flexible cou-
plings is essential to prevent excessive vibration and bearing or shaft failures.
D $OLJQPHQW3URFHGXUH
)OH[LEOH&RXSOLQJ1RQ6HOI6XSSRUWLQJ%DVHV
Before grouting the base, the coupling should be checked as follows:
1. Sl ide the sleeve from the coupl ing so t hat th e hub faces are ex posed.
2. Check that the coupling h ub spacing is in accor dance with the outline dimensions with
the units in the mechanical center of their end play.
3. Check parallel alignment by using a straightedge across the hubs at both vertical and
horizontal locations, or by clamping a dial indicator to one hub and indicating the other
hub on its outside diameter. Be sure that the dial indicator supports do not bend or sag,
since this will give inaccurate readings.
4. Use a dial indicator at hub faces and rotate both units together 90°, 180°, 270° and 360°
or measure the gap at each position by inserting a feeler gage. The reading should not
vary more than 0.002”.
5. Correct any vertical misalignment by shimming between the base and the foundation.
8
Horizontal alignment should be corrected by shifting machines on the base.
b. Ali gnment Proc edur e
Flex ible Coupl ings, Self-Supporting Bases
Before operating the machine, the base should be bolted down and the alignment checked as
follows:
1. Remove all of the coupling bolts and slide the shells back so that the hub faces are exposed.
2. Check the coupling hub spacing in accordance with the outline dimensions with the
units in the mechanical center of their end play.
3. Check parallel alignment by using a straightedge across the hubs at both vertical and
horizontal locations or by clamping a dial indicator to one hub and indicating the other
hub on its outside diameter. Be sure that the dial indicator supports do not bend or sag,
since this will give inaccurate readings.
4. Use the dial indicator at hub faces and rotate both units together 90°, 180°, 270° and
360° or measure the gap at each position by inserting a feeler gage. The readings should
not vary more than 0.002”.
GEH-5304A
5. Correct any vertical misalignment by shimmin g under the units. Horizontal alignment
should be cor rected by shifting machine on the base.
2. Grouting
On concrete foun dations, a minimum of 1” should be allowed for grouting.
A rich, non-shrink grout should be used. High-grade grout mixtures are available commercially. If
the grout is to be prepared at the site, a cement-sand ratio of 1:2 is recommended. No more than
enough water should be used to give a stiff mixture. The clean but rough surface of the foundations
should be wet and the gr out forced or puddled under the base.
3. V-Belt Drives
The V-belt system produces a heavy shaft and bearing loading, making it necessary that these factor s
be considered carefully for proper application. Since belt drives impose a bending moment on the
motor shaft, it is always desirable to h ave the motor sheave located as close to the motor bearing as
possible to minimize both bearing load and shaft stress. This will result in increased bearing life. For
the load centered 2” in toward th e bearing from the end of the shaft instead of at the end of the shaft,
the bearing load is reduced by 10% an d th e life increased by 33%. The bearing life curves that follow
assume the load is centered at the end of the shaft. New improved V-belts are now on the market that
significantly reduce the number and size of belts required for a given load. These new belts should
always be considered, since the sheave will be shorter and the load centered closer to the bearing.
The standard NEMA shaft extension is designed for belted loads. Dimensions are provided on the
standard dimension sheets. A sliding base is available as an accessory to facilitate belt adjustment.
4. Bearing Life
Bearing life for belted drives is determined by calculating the radial load at the end of the shaft.
9
GEH-5304A
The radial load, W, produced by th e belts when tightened just enough to transmit the load with out
slipping is given by the relation:
126,000 x HP
W = x K
, lbs
b
D x RPM
Where:
D = Sheave pitch diameter in inches for V-belt application
HP
RPM
K
=
Maximum ratio of horsepower, including overloads, to the minimum speed at which that
power occurs.
= Belt tension factory from table below:
b
Belt Tension Factor, K
K
b
b
Description
1.0 Chain and Sprocket Dr ive
1.2 Tim ing Belt
1.5 V-Belt, 1:1 Ratio
1.8 V-Belt, 2:1 Speed Decreased Ratio
2.0 Flat Belts
The curves that follow can be used to determine the anticipated L10 life, which is the life in hours that
90% of bearings with th is load would be expected to exceed withou t failure. The standard ball bearing and standard shaft option will be the most economic, if acceptabl e life i s obtained from the curve.
A good commonly used design figure is 20,000 hours. However , applications with a calculated life of
as low as 5,000 hours have sometimes been necessary to limit belt speeds to 6,000 feet per minute.
The curves are drawn for 1750 RPM average speed. If the application has some ot her average speed,
the life can be adjusted by multiplying by th e bearing life factor.
It is important to know that bearing life for V-belt applications is independent of the motor load.
Once the belts have been tightened just enough to prevent slipping when the maximum torque is being
delivered by the motor the radial load, W, on the shaft and bearing is there and r emains constant regardless of whether the motor is even turning. For timing belts and chain drives, the radial load, W,
does not vary somewhat with motor load. Therefore, the motor load duty cycle as well as the average
speed should be considered to estimate bearing life.
Belt tension should be checked and adjusted following the belt manufacturers’ recommendations.
If slippage occurs after the belt tension has been correctly adjusted, the belts and pulleys have not been
chosen properly for the application.
Over-tightening to avoid this slippage may result in early failures of belts, shafts
and bearings.
There is normally a drop in tension during the first 24 to 48 hours of operation. During this “run in”
per iod, th e belts sea t th emselves in th e shea ve grooves a nd in itial stretch is removed. Belt tension
should be re-checked after a day or two of operation.
Matched belts run smoother and last longer. Longer belt life results if the belts and sheaves are kept
clean and the belts are prevented from rubbin g against the belt guards or other obstructions.
10
Mounting may be either horizontal or vertical for these bearing life determinations, as long as no axial
load (i.e., suspended load) other than the weight of the armature is present if vertical.
5. Special Load Considerat ions
Where the load is overh ung beyond the motor shaft extension or greater bearing life is desired, the
application should be referred to GE Industrial Systems.
6. Pi nion Drives
While Kinamatic motors are not designed for overhung pinion drives, they may be successfully applied under suitable conditions. In addition to a radial load, some gears produce thrust load on the
bearing. Complete details of the proposed gearing should be referred to GE Industrial Systems in all
cases.
7. Thrust Loads
Due to the mounting position or type of drive arrangement, a thrust load may be applied to the motor
shaft. The Kinamatic motor is designed to permit a limited amount of thrust load. This permissible
load will vary by mounting position and direction of the load due to the weight of the armature. The
permissible load in Table 2 is tabulated by frame diameter and mounting position. These apply to
ball bearings only.
GEH-5304A
For applications combin ing thrust and radial loads or where thrust loads exceed th e values sh own in
Table 2, refer all details to GE Industrial Systems.
Table 2
Maximum Continuous Thrust Capacity, Lbs.*
Vertical Mounti ng
Bearing Horizontal Thrust Load Thrust Load
Frame Size Mounting Up Down
2512 Std-309 350 465 235
2512 O/S - 310 400 515 285
2513 Std-309 350 485 215
2513 O/S - 310 400 585 265
2812 Std-310 400 550 250
2812 O/S - 311 500 650 350
2813 Std-310 400 585 215
2813 O/S - 311 500 685 315
*Based on L10 life of 20, 000 hour s and an average speed not ex c eeding 2500 RPM.
IV. OPERATION
Disconnect power before touching any internal part. High voltage may be present even wh en the machine is not rotating. If used with a rectified power supply, disconnect all AC line connections to power supply. With other power
supplies, disconnect all DC line and field connections. Also disconnect power
from auxil iary devices.
Ground the machine properly to avoid serious injury to personnel. Grounding
must be in accordance with the National Electrical Code and consistent with
sound local practices. One of the bolts holding the conduit box to the unit, accessible from inside the conduit box, is identified and may be used for attach ing a grounding cable.
11
Before starting the motor, remove all unused shaft keys and loose rotating parts
to prevent t hem from flying off.
A. Inspection Before Star ting
These inspection procedures should be followed befor e starting the machine for the first time, after an extended shutdown or after a teardown for extensive maintenance or repair.
1. Bearings and Couplings
Machines with ball or roller bearings are greased at the factory an d will need no attention until r elubrication is necessary as suggested in the Maintenance section of thi s in struction book.
If the flexible couplings are a lubricated type, they should be checked to see that they contain the
proper amount of lubricant.
Make sure that all grease plugs are tight.
2. Com mutator and B r ushes
GEH-5304A
Brushes should be worn in to ha ve at least 85% contact over the brush surface and continuous contact
from heel to toe. The commutator surface and undercut mica should be clean and free from dirt,
grease, paint spots or brush dust.
Brushes should be free to move in the holders and all springs should be down and latched. Brush
pigtail connections should be tight and the pigtails should not interfere with the action of the spring or
brush and should be clear of any other part of the machine.
B. Rectified Power Suppl ies
When DC motors are operated from rectified power supplies, the pulsating voltage and current wave forms
affect the motor perfor mance by increasing motor heating and degrading commutation. Because of these effects, it is necessary th at th e motors be designed or specially selected to suit this type of operation.
The ratings of DC motor s intended for operation from rectified power supplies are based upon motor tests
using a suitable power supply. The specific characteristics for three-phase rectified power supplies described
in the Power Supply Identification section are in common use. For operation of motors from rectified
power supplies other than those given in this section, refer to GE Industrial Systems.
A motor may, under some conditions, be operated from a power supply different from that indicated on the
nameplate. Letters used to identify power supplies in common use have been chosen in alphabetical order of
increasing magnitude of ripple current. Power supply compatibility can be judged by Table 4.
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GEH-5304A
Table 3
Bearing Life at 1750 RPM Average Speed Vs. Load , W
(For other average speeds, m ultiply li fe by l ife factor)
Less Than
Speed 500 650 850 1150 1500 2000 2500 3000 4000 5000
Life Factor 2.15 1.83 1.55 1.29 1.10 .92 .80 .72 .60 .55
Frame Sizes
CD2512AT and CD2513AT
Description
Curve Bearing Diameter Material
1 Standard
Ball
(309)
2 Oversize
Ball
(310)
3 Oversize
Roller
(310)
Shaft Shaft
Standard (1-5/8) Standard
Oversize (1-7/8) Standard
Oversize (1-7/8) Special
Frame Sizes
CD2812AT and CD2813AT
Description
Curve Bearing Diameter Material
1 Standard
Ball
(310)
2 Oversize
Ball
(311)
3 Oversize
Roller
(311)
Shaft Shaft
Standard (1-7/8) Standard
Oversize (2-1/8) Standard
Oversize (2-1/8) Special
13
Table 4
Power Supply Available
ACDEK
NP Rating Code
A
C
D
E
K
√
√√
√√√
√√√√
√√√√√
****
***
**
*
√ Compatible power supply.
* External inductanc e may be necessary to limit ripple current.
C. Power Supply Identification
The nameplates of DC motors intended for operation from rectified power supplies will be stamped with a
power supply identification as described below.
1. When the test power supply used as the basis of rating is one of the five described below, a single
letter "A”, “C”, “D”, “E” or “K” will be used to identify the test power supply.
GEH-5304A
a. Power Supply Identification Letter “A ”
This designates a DC generator, battery or any power supply with enough series inductance to
result in no more than 6% peak-to-peak armature current ripple.
b. Power Supply Identification Letter “C”
This designates a three-phase, 60 hertz input, full-wave power supply having six total (controlled) pulses per cycle. The power supply has no free-wheeling and no series inductance.
The input line-to-line AC voltage to the rectifier shall be 230 volts for 240 volt DC motor ratings, and 460 volts for 500 or 550 volt DC motor ratings.
c. Power Supply Identi fic ation Letter “ D”
This designates a three-phase, 60 hertz input, semi-bridge power supply having threecontrolled pulses per cycle. The supply has free wheeling with no series inductan ce added externally to the motor armature circuit. The input line-to-line AC voltage to the rectifier shall be
230 volts for 240 volt DC motor ratings and 460 volts for 500 or 550 volt DC motor ratings.
d. Power Supply Identification Letter “E ”
This designates a three-phase, single-way (h alf-wave) power supply having three total pulses
per cycle and thr ee-controlled pulses per cycle. The power supply has no free wheeling a nd n o
series inductance added externally to the motor armatur e circuit inductance. The input line-toline AC voltage to the rectifier shall be 460 volts for 240 volt DC motor ratings.
e. Power Supply Identification Letter “K ”
This designates a single-phase, full-wave power supply having two total (controlled) pulses per
cycle with free wh eeling 60 hertz input and no series inductance added externally to th e motor
armature circuit. The input AC voltage to the rectifier shall be 230 volts for 180 volt DC ratings.
14
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