Baldor-Reliance B910395, B910365, B910302, CDMG2325, CDMG2320 User Manual

Integral Horsepower

DC Motor

Installation & Operating Manual

2/09 MN605

Any trademarks used in this manual are the property of their respective owners.

Table of Contents

Section 1

General Information 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overview 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Limited Warranty 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Safety Notice 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Receiving 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lifting Magnet Generators 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Handling 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Storage 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Preparation for Storage 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removal From Storage 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Section 2

Installation & Operation 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overview 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Location 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mounting 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Alignment 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Doweling & Bolting 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Guarding 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power Connection 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Conduit Box 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Motor Connections 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Thermostats 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Initial Start-Up 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Coupled Start-Up 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Section 3
Maintenance & Troubleshooting 3-1.

General Inspection 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lubrication & Bearings 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Type of Grease 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lubrication Intervals 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lubrication Procedure 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Brush Replacement 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Brush Springs 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Poor Brush Life 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Brush Chatter or Bounce 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Brush Sparking 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Carbon Brushes For Special Operating Conditions 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Authorized Service 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Humidity And Brush Wear 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Continued on next page

Table of Contents iMN605

Guide To Commutator Appearance 3-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Commutator 3-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Rapid Commutator Wear 3-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Turning The Commutator 3-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Commutator Undercutting 3-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Blowers & Filters 3-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting 3-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Armature Overheating 3-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Field Coil Overheating 3-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Excessive Load 3-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Jogging and Repeated Starts 3-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Heating 3-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Thermostat 3-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting Chart 3-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Accessories 3-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Reflash Instructions 3-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Section 4

Connection Diagrams 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ii Table of Contents MN605

Section 1
General Information

Overview This manual contains general procedures that apply to Baldor Motor products. Be sure to read and

understand the Safety Notice statements in this manual. For your protection, do not install, operate or
attempt to perform maintenance procedures until you understand the Warning and Caution statements.
A Warning statement indicates a possible unsafe condition that can cause harm to personnel.
A Caution statement indicates a condition that can cause damage to equipment.

Important: This instruction manual is not intended to include a comprehensive listing of all details for all

procedures required for installation, operation and maintenance. This manual describes general
guidelines that apply to most of the motor products shipped by Baldor. If you have a question
about a procedure or are uncertain about any detail, Do Not Proceed. Please contact your Baldor
distributor for more information or clarification.

Before you install, operate or perform maintenance, become familiar with the following:

S NEMA Publication MG 2, Safety Standard for Construction and guide

for Selection, Installation and Use of Electric Motors and Generators.

S The National Electrical Code
S Local codes and Practices

Limited Warranty

www.baldor.com/support/warranty_standard.asp

Safety Notice: This equipment contains high voltage! Electrical shock can cause serious or fatal injury. Only qualified

personnel should attempt installation, operation and maintenance of electrical equipment.
Be sure that you are completely familiar with NEMA publication MG 2, safety standards for construction

and guide for selection, installation and use of electric motors and generators, the National Electrical
Code and local codes and practices. Unsafe installation or use can cause conditions that lead to serious
or fatal injury. Only qualified personnel should attempt the installation, operation and maintenance of this
equipment.

WARNING: Do not touch electrical connections before you first ensure that power has been disconnected.

Electrical shock can cause serious or fatal injury. Only qualified personnel should attempt the
installation, operation and maintenance of this equipment.

WARNING: Disconnect all electrical power from the motor windings and accessory devices before

disassembly of the motor. Electrical shock can cause serious or fatal injury.

WARNING: Be sure the system is properly grounded before applying power. Do not apply power before you

ensure that all grounding instructions have been followed. Electrical shock can cause serious or
fatal injury. National Electrical Code and Local codes must be carefully followed.

WARNING: Avoid extended exposure to machinery with high noise levels. Be sure to wear ear protective

devices to reduce harmful effects to your hearing.

WARNING: Surface temperatures of motor enclosures may reach temperatures which can cause discomfort

or injury to personnel accidentally coming into contact with hot surfaces. When installing,
protection should be provided by the user to protect against accidental contact with hot surfaces.
Failure to observe this precaution could result in bodily injury.

WARNING: This equipment may be connected to other machinery that has rotating parts or parts that are

driven by this equipment. Improper use can cause serious or fatal injury. Only qualified
personnel should attempt to install operate or maintain this equipment.

WARNING: Do not by-pass or disable protective devices or safety guards. Safety features are designed to

prevent damage to personnel or equipment. These devices can only provide protection if they
remain operative.

WARNING: Avoid the use of automatic reset devices if the automatic restarting of equipment can be

hazardous to personnel or equipment.

WARNING: Be sure the load is properly coupled to the motor shaft before applying power. The shaft key

must be fully captive by the load device. Improper coupling can cause harm to personnel or
equipment if the load decouples from the shaft during operation.

WARNING: Use proper care and procedures that are safe during handling, lifting, installing, operating and

maintaining operations.
Improper methods may cause muscle strain or other harm.

WARNING: UL listed motors must only be serviced by authorized Baldor Service Centers if these motors are

to be returned to a flammable and/or explosive atmosphere.

General Information 1-1MN605

Safety Notice Continued
WARNING: Pacemaker danger − Magnetic and electromagnetic fields in the vicinity of current carrying

carrying conductors and permanent magnet motors can result result in a serious health hazard to
persons with cardiac pacemakers, metal implants, and hearing aids. To avoid risk, stay way from
the area surrounding a permanent magnet motor.

WARNING: Before performing any motor maintenance procedure, be sure that the equipment connected to

the motor shaft cannot cause shaft rotation. If the load can cause shaft rotation, disconnect the
load from the motor shaft before maintenance is performed. Unexpected mechanical rotation of
the motor parts can cause injury or motor damage.

WARNING: Use only UL/CSA listed explosion proof motors in the presence of flammable or combustible

vapors or dust.

WARNING: Motors that are to be used in flammable and/or explosive atmospheres must display the UL label

on the nameplate along with CSA listed logo. Specific service conditions for these motors are
defined in NFPA 70 (NEC) Article 500.

WARNING: Guards must be installed for rotating parts such as couplings, pulleys, external fans, and unused

shaft extensions, should be permanently guarded to prevent accidental contact by personnel.
Accidental contact with body parts or clothing can cause serious or fatal injury.

WARNING: Thermostat contacts automatically reset when the motor has slightly cooled down. To prevent

injury or damage, the control circuit should be designed so that automatic starting of the motor is
not possible when the thermostat resets.

Caution: To prevent premature equipment failure or damage, only qualified maintenance personnel should

perform maintenance.
Caution: Do not over−lubricate motor as this may cause premature bearing failure.
Caution: Do not over tension belts. Excess tension may damage the motor or driven equipment.
Caution: Do not lift the motor and its driven load by the motor lifting hardware. The motor lifting hardware

is adequate for lifting only the motor. Disconnect the load from the motor shaft before moving the

motor.
Caution: If eye bolts are used for lifting a motor, be sure they are securely tightened. The lifting direction

should not exceed a 20° angle from the shank of the eye bolt or lifting lug. Excessive lifting

angles can cause damage.
Caution: To prevent equipment damage, be sure that the electrical service is not capable of delivering more

than the maximum motor rated amps listed on the rating plate.
Caution: If a HI POT test (High Potential Insulation test) must be performed, follow the precautions and

procedure in NEMA MG 1 and MG 2 standards to avoid equipment damage.
Caution: Series wound motors must never be allowed to run with no load (broken belt etc.)

An unloaded motor may reach destructive high speeds.
Caution: Do not use Silicone grease or Sealing Compounds (RTV) on or in the vicinity of the motor or its air

supply. Silicone vapor inside the motor will result in extremely rapid brush wear.
Caution: Motors designed for forced ventilation must have cooling air when fields are excited at rated

voltage. Installations having the air supply interrupted when the motor is not operating must have

field disconnected or field voltage reduced to 67% rated by means of field economizing resistor

and relay or motor insulation life will be significantly reduced.

If you have any questions or are uncertain about any statement or procedure, or if you require additional

information please contact your Baldor distributor or an Authorized Baldor Service Center.

Receiving

Lifting Magnet Generators

Each BaldorSReliance motor is thoroughly tested at the factory and carefully packaged for shipment.

When you receive your motor, there are several things you should do immediately.

1. Observe the condition of the shipping container and report any damage immediately to the
commercial carrier that delivered your motor.

2. Verify that the part number of the motor you received is the same as the part number listed on your
purchase order.

Treat Baldor lifting magnet generators like motors during installation or maintenance.
Generally, they have standard compound self-excited fields. Standard magnetism is for counter-clockwise
rotation (facing the drive end of the motor). To reverse (operate clockwise), refer to the connection
diagrams in Section 4 of this manual.

1-2 General Information MN605

Caution: Do not lift the motor and its driven load by the motor lifting hardware. The motor lifting hardware

is adequate for lifting only the motor. Disconnect the load from the motor shaft before moving the
motor.

Handling

Storage

Preparation for Storage

The motor should be lifted using the lifting lugs or eye bolts provided.

1. Use the lugs or eye bolts provided to lift the motor. Never attempt to lift the motor and additional
equipment connected to the motor by this method. The lugs or eye bolts provided are designed to lift
only the motor. Never lift the motor by the motor shaft or the hood of a WPII motor. If eye bolts are
used for lifting a motor, be sure they are securely tightened. The lifting direction should not exceed a
20° angle from the shank of the eye bolt. Excessive lifting angles can cause motor damage.

2. To avoid condensation inside the motor, do not unpack until the motor has reached room temperature.
(Room temperature is the temperature of the room in which it will be installed).
The packing provides insulation from temperature changes during transportation.

3. When lifting a WPII (Weather Proof Type 2) motor, do not lift the motor by inserting lifting lugs into
holes on top of the cooling hood. These lugs are to be used for hood removal only.
A spreader bar should be used to lift the motor by the cast lifting lugs located on the motor frame.

4. If the motor must be mounted to a plate with the driven equipment such as pump, compressor etc.,
it may not be possible to lift the motor alone. For this case, the assembly should be lifted by a sling
around the mounting base. The entire assembly can be lifted as an assembly for installation.
Do not lift the assembly using the motor lugs or eye bolts provided. Lugs or eye bolts are designed to
lift motor only. If the load is unbalanced (as with couplings or additional attachments) additional slings
or other means must be used to prevent tipping. In any event, the load must be secure before lifting.

Storage requirements for motors and generators that will not be placed in service for at least six months
from date of shipment. To avoid condensation inside the motor, do not unpack until the motor has
reached room temperature. (Room temperature is the temperature of the room in which it will be
installed). The packing provides insulation from temperature changes during transportation.

Improper motor storage will result in seriously reduced reliability and failure. An electric motor that does
not experience regular usage while being exposed to normally humid atmospheric conditions is likely to
develop rust or rust particles on surrounding surfaces to contaminate the bearings. The electrical
insulation may absorb an excessive amount of moisture leading to the motor winding failure.

A wooden crate “shell” should be constructed to secure the motor during storage. This is similar to an
export box but the sides & top must be secured to the wooden base with lag bolts (not nailed as export
boxes are) to allow opening and reclosing many times without damage to the “shell”.

1. Some motors have a shipping brace attached to the shaft to prevent damage during transportation.
The shipping brace, if provided, must be removed and stored for future use. The brace must be
reinstalled to hold the shaft firmly in place against the bearing before the motor is moved.

2. Store in the original containers in a clean, dry, protected warehouse where these controlled:
a. Shock or vibration must not exceed 2 mils maximum at 60 hertz, to prevent the bearings from

brinelling. If shock or vibration exceeds this limit vibration isolation pads must be used.
b. Storage temperatures of 10°C (50°F) to 49°C (120°F) must be maintained.
c. Relative humidity must not exceed 60%.
d. Motor space heaters (optional) are to be connected and energized whenever there is a possibility

that the storage ambient conditions will reach the dew point. Space heaters are optional.

Note: Remove motor from containers when heaters are energized, reprotect if necessary.

3. Measure and record the resistance of the winding insulation every 30 days of storage.
a. If motor insulation resistance decreases to less than 5 Meg ohms, contact your Baldor District

office.
b. Place new desiccant inside the vapor bag and re−seal by taping it closed.
c. If a zipper−closing type bag is used instead of the heat−sealed type bag, zip the bag closed

instead of taping it. Be sure to place new desiccant inside bag after each monthly inspection.
d. Place the shell over the motor and secure with lag bolts.

4. Where motors are mounted to machinery, the mounting must be such that the drains and breathers
are fully operable and are at the lowest point of the motor. Vertical motors must be stored in the
vertical position. Storage environment must be maintained as stated in step 2.

General Information 1-3MN605

5. Motors with anti−friction bearings are to be greased at the time of going into extended storage with
periodic service as follows:

a. Motors marked “Do Not Lubricate” on the nameplate do not need to be greased before or during

storage.

b. Ball and roller bearing (anti−friction) motor shafts are to be rotated manually every 3 months and

greased every 6 months in accordance with the Maintenance section of this manual.

c. Sleeve bearing (oil lube) motors are drained of oil prior to shipment. The oil reservoirs must be

refilled to the indicated level with the specified lubricant, (see Maintenance). The shaft should be
rotated monthly by hand at least 10 to 15 revolutions to distribute oil to bearing surfaces.

d. “Provisions for oil mist lubrication” – These motors are packed with grease.

Storage procedures are the same as paragraph 5b.

e. “Oil Mist Lubricated” – These bearings are protected for temporary storage by a corrosion

inhibitor. If stored for greater than 3 months or outdoor storage is anticipated, connected to the oil
mist system while in storage. If this is not possible, add the amount of grease indicated under
“Standard Condition” in Section 3, then rotate the shaft 15 times by hand.

6. All breather drains are to be fully operable while in storage (drain plugs removed). The motors must
be stored so that the drain is at the lowest point. All breathers and automatic “T” drains must be
operable to allow breathing and draining at points other than through the bearings around the shaft.
Vertical motors should be stored in a safe stable vertical position.

7. Coat all external machined surfaces with a rust preventing material.
An acceptable product for this purpose is Exxon Rust Ban # 392.

8. Carbon brushes should be lifted and held in place in the holders, above the commutator, by the brush
holder fingers. The commutator should be wrapped with a suitable material such as cardboard paper
as a mechanical protection against damage.

Non−Regreaseable Motors

Non−regreasable motors with “Do Not Lubricate” on the nameplate should have the motor shaft rotated
15 times to redistribute the grease within the bearing every 3 months or more often.

All Other Motor Types

Before storage, the following procedure must be performed.

1. Remove the grease drain plug, if supplied, (opposite the grease fitting) on the bottom of each bracket
prior to lubricating the motor.

2. The motor with regreasable bearing must be greased as instructed in Section 3 of this manual.

3. Replace the grease drain plug after greasing.

4. The motor shaft must be rotated a minimum of 15 times after greasing.

5. Motor Shafts are to be rotated at least 15 revolutions manually every 3 months and additional grease
added every nine months (see Section 3) to each bearing.

6. Bearings are to be greased at the time of removal from storage.

Removal From Storage

1. Remove all packing material.

2. Measure and record the electrical resistance of the winding insulation resistance meter at the time of
removal from storage. The insulation resistance must not be less than 50% from the initial reading
recorded when the motor was placed into storage. A decrease in resistance indicates moisture in the
windings and necessitates electrical or mechanical drying before the motor can be placed into
service. If resistance is low, contact your Baldor District office.

3. Regrease the bearings as instructed in Section 3 of this manual.

4. Reinstall the original shipping brace if motor is to be moved. This will hold the shaft firmly against the
bearing and prevent damage during movement.

1-4 General Information MN605

Section 2
Installation & Operation

Overview Installation should conform to the National Electrical Code as well as local codes and practices.

When other devices are coupled to the motor shaft, be sure to install protective devices to prevent future
accidents. Some protective devices include, coupling, belt guard, chain guard, shaft covers etc.
These protect against accidental contact with moving parts. Machinery that is accessible to personnel
should provide further protection in the form of guard rails, screening, warning signs etc.

Caution: Do not use Silicone grease or Sealing Compounds (RTV) on or in the vicinity of the motor or its air

supply. Silicone vapor inside the motor will result in extremely rapid brush wear.

Location The motor should be installed in an area that is protected from direct sunlight, corrosives, harmful gases

or liquids, dust, metallic particles, and vibration. Exposure to these can reduce the operating life and
degrade performance. Be sure to allow clearance for ventilation and access for cleaning, repair, service
and inspections. Ventilation is extremely important. Be sure the area for ventilation is not obstructed.
Obstructions will limit the free passage of air. Motors get warm and the heat must be dissipated to
prevent damage.

These motors are not designed for atmospheric conditions that require explosion proof operation.
They must NOT

TEFC motors can be used for indoor or outdoor standard service. They cannot be used outdoors where
they would be exposed to freezing rain. Standard TEFC motors are not designed for atmospheric
conditions requiring explosion-proof operation, such as flammable or combustible vapors or dust.

Caution: Do not lift the motor and its driven load by the motor lifting hardware. The motor lifting hardware

is adequate for lifting only the motor. Disconnect the load (gears, pumps, compressors, or other
driven equipment) from the motor shaft before lifting the motor.

Mounting The motor must be securely installed to a rigid foundation or mounting surface to minimize vibration and

maintain alignment between the motor and shaft load. Failure to provide a proper mounting surface may
cause vibration, misalignment and bearing damage.

Foundation caps and sole plates are designed to act as spacers for the equipment they support. If these
devices are used, be sure that they are evenly supported by the foundation or mounting surface.

After installation is complete and accurate alignment of the motor and load is accomplished, the base
should be grouted to the foundation to maintain this alignment.

The standard motor base is designed for horizontal or vertical mounting. Adjustable or sliding rails are
designed for horizontal mounting only. Consult your Baldor distributor or authorized Baldor Service
Center for further information.

Alignment Accurate alignment of the motor with the driven equipment is extremely important.

1. Direct Coupling
For direct drive, use flexible couplings if possible. Consult the drive or equipment manufacturer for
more information. Mechanical vibration and roughness during operation may indicate poor alignment.
Use dial indicators to check alignment. The space between coupling hubs should be maintained as
recommended by the coupling manufacturer.

2. End-Play Adjustment
The axial position of the motor frame with respect to its load is also extremely important. The motor
bearings are not designed for excessive external axial thrust loads. Improper adjustment will cause
failure.

3. Pulley Ratio
The pulley ratio should not exceed 8:1. Consult your Baldor distributor or authorized Baldor Service
Center for further information.

Caution: Do not over tension belts. Excess tension may damage the motor or driven equipment.

4. Belt Drive
Refer to NEMA MG 1 section 14.07 or Baldor application section for the application of pulleys,
sheaves, sprockets, and gears. Align sheaves carefully to minimize belt wear and axial bearing loads
(see End-Play Adjustment). Belt tension should be sufficient to prevent belt slippage at rated speed
and load. However, belt slippage may occur during starting. Do not over-tension belts.

Caution: Series wound motors must never be allowed to run with no load (broken belt etc.)

An unloaded motor may reach destructive high speeds.

be used in the presence of flammable or combustible vapors or dust.

Installation & Operation 2-1MN605

Doweling & Bolting After proper alignment is verified, dowel pins should be inserted through the motor feet into the

foundation. This will maintain the correct motor position should motor removal be required. (Baldor
motors are designed for doweling.)

1. Drill dowel holes in diagonally opposite motor feet in the locations provided.

2. Drill corresponding holes in the foundation.

3. Ream all holes.

4. Install proper fitting dowels.

5. Mounting bolts must be carefully tightened to prevent changes in alignment. Use a flat washer and
lock washer under each nut or bolt head to hold the motor feet secure. Flanged nuts or bolts may be
used as an alternative to washers.

WARNING: Guards must be installed for rotating parts such as couplings, pulleys, external fans, and unused

shaft extensions, should be permanently guarded to prevent accidental contact by personnel.
Accidental contact with body parts or clothing can cause serious or fatal injury.

Guarding Guards must be installed for rotating parts such as couplings, pulleys, external fans, and unused shaft

extensions. This is particularly important where the parts have surface irregularities such as keys, key
ways or set screws. Some satisfactory methods of guarding are:

1. Covering the machine and associated rotating parts with structural or decorative parts of the driven
equipment.

2. Providing covers for the rotating parts. Covers should be sufficiently rigid to maintain adequate
guarding during normal service.

Power Connection Motor and control wiring, overload protection, disconnects, accessories and grounding should

conform to the National Electrical Code and local codes and practices. Ground the motor by attaching a
strap from an established ground point to the grounding bolt provided inside the conduit box.

Conduit Box For ease of making connections, an oversize conduit box is provided. The box can be rotated 360°

in 90° increments.

Power Connect the motor leads as shown on the connection diagram located on the name plate or inside the

cover on the conduit box. Be sure the following guidelines are met:

1. DC power is within ±5% of rated voltage (not to exceed 600VDC). (See motor name plate for ratings).

OR

2. DC field power is within ±1% of rated voltage.

Motor Connections Terminal connections should be made as specified. See the connection diagrams located in

Section 4 of this manual. Tables 2−1 and 2−2 show the NEMA standard lead markings and the Accessory
Markings.

Table 2−1 NEMA Standard Lead Markings

Lead Markings

Armature A1, A2

Field (shunt) F1, F2, F3, F4, etc.

Field (series) S1, S2

Thermostat P1, P2, etc.

Space Heater H1, H2, H3, H4, etc.

Resistance Temperature Detector (RTD) R1, R2, R3, R4, etc.

Optional Brush Monitor System A1Probe, A2Probe

Motor

2-2 Installation & Operation MN605

DC Tachometers

AC Tachometers 45/90V Output

Brake Coil Leads B1, B2, B3, etc.
Space Heater (Brake) H1, H2, H3, H4, etc.
Brake Interlock Switch BS1, BS2, BS3, etc.

Electrically

Isolated

Encoder

Standard Receptacle MS3112W12−10P
Standard Plug MS3116J12−10S

Table 2−2 Accessory Markings

XPY 1 2 G

XC Red (1) Black (2) G

NCS Pancake Red Black

45V Red White
90V Red Black

Figure 2-1 Encoder Connections

Color Codes for Optional

Baldor Encoder Cable

A
H
B

J
C
K
D
F

E

+ —

A
A
B

B
C
C
+5V
COMMON

AB

H

K

GJC

FED

Thermostats The thermostat is a pilot circuit device used in a protective relay circuit. The thermostat ratings are given

in Table 2−3.

Table 2−3 Thermostat Ratings

Maximum Current Ratings for Thermostats (Normally Open or Closed Contacts)

Voltage 125VAC 250VAC 24VDC Continuous Current

All Voltages

Amperage 12A 8A 2A 2A

Installation & Operation 2-3MN605

Blower Ventilation System

Before loading a force-ventilated motor, be sure that the blowers, cooling fans, or central air supply
systems are operating properly to supply cooling air to the motor. Air filters should also be in place. If you
energize the main fields with the motor at standstill, the blowers or external cooling systems must be left
on. This will prevent excessive heat buildup that will decrease the life of the insulation.

When using field economy circuits to reduce the voltage to the main fields during standstill, blowers do
not need to be left on.

Blower motors should be checked for correct rotation. Don’t rely on feeling airflow from the drive end of
the motor. Look at the outline drawing or rotation arrow shown on the blower housing. Refer to Figure
2-1.

Figure 2-1 View from Air Inlet (Motor is on Opposite Side)

Air Inlet

Housing

Impeller
Blades

Airflow

Table 2−4 Electrical Data - Forced Ventilation Blower Units

Size

Motor Frame HP RPM Volts Phase Hz Amps

LM2 180 1/40 3000 230 1 60 0.4
LM3 180 1/8 3450 115/230 1 50/60 2.6/1.3
LM3 210-250 1/8 3450 208-230/460 3 50/60 0.66-0.60/0.30
LM4 280 1/3 3450 208-230/460 3 50/60 1.5-1.4/0.7
LM6 320-400 1 3450 208-230/460 3 50/60 3.1-3.0/1.5
LM8 504-506 3/4 1750 208-230/460 3 50/60 3.4-3.2/1.6
LM9 508-5012 3 3450 208-230/460 3 50/60 8.2-7.6/3.8

Note: Motor mounted blower units. Mount on commutator end (opposite drive end of motor. We supply

blowers that are powered by totally enclosed motors (standard). Blowers have a cast aluminum fan
housing with washable, wire mesh filters.

2-4 Installation & Operation MN605

Table 2−5 Minimum Blower CFM for DPBV Motors (Drip Proof Blower Ventilated)

Blower Size

LM2 180 55 0.50
LM3 180 150 1.45
LM3 210 175 1.45
LM3 250 215 0.78
LM4 280 350 0.88
LM6 320 780 2.80
LM6 360 780 2.80
LM6 400 820 2.50
LM8 504-506 1120 1.58
LM9 508-5012 2000 5.00

Each motor nameplate is stamped with the above data for DPBV (less Blower),
DPSV and TEPV enclosures.

Caution: Motors designed for forced ventilation must have cooling air when fields are excited at rated

voltage. Installations having the air supply interrupted when the motor is not operating must have
field disconnected or field voltage reduced to 67% rated by means of field economizing resistor
and relay or motor insulation life will be significantly reduced.

Motor Frame Size Blower CFM Blower Static Pressure

(In H

O)

2

Initial Start-Up If driven equipment can be damaged by rotating in the wrong direction, uncouple the motor from the

load before checking for rotation.

Caution: Series wound motors must never be allowed to run with no load (broken belt etc.)

An unloaded motor may reach destructive high speeds.

If the direction of rotation needs to be corrected, disconnect the input power supply and interchange the
appropriate leads. Refer to the motor connection diagrams in Section 4 of this manual.

1. The first start-up and running of the motor should be with the motor uncoupled from the load.

2. Check the direction of rotation by momentarily applying power to the motor.

3. With the motor running, make sure it’s running smoothly without too much noise or vibration. If either
are present, shut down the motor immediately and find the cause of the problem.

Coupled Start-Up

1. After the first successful no load start-up, stop the motor and assemble the coupling.

2. Align the coupling and be sure it is not binding in any way.

3. The first coupled start-up should be without load. Check to see that the driven equipment is not
transmitting any vibration back to the motor through the coupling or the base. Vibrations (if any)
should be within acceptable levels.

4. Run about 1 hour with driven equipment unloaded.

5. After completing these steps, the motor can now be loaded.

6. Do not exceed the value of armature nameplate amperes under steady continuous loads.

Installation & Operation 2-5MN605

2-6 Installation & Operation MN605

Section 3
Maintenance & Troubleshooting

General Inspection Inspect the motor at regular intervals, approximately every 500 hours of operation or every 3

months, whichever occurs first. Keep the motor clean and the ventilation openings clear. The following
steps should be performed at each inspection:

1. Check that the motor is clean. Check that the interior and exterior of the motor is free of dirt, oil,
grease, water, etc. Oily vapor, paper pulp, textile lint, etc. can accumulate and block motor
ventilation. If the motor is not properly ventilated, overheating can occur and cause early motor
failure.

2. Periodically measure the motor winding resistance to ensure that the integrity of the winding
insulation has been maintained. Record the motor winding resistance. Immediately investigate any
significant drop in insulation resistance.

3. Check all electrical connectors to be sure that they are tight.

4. Check for too much vibration or looseness. It may be caused by improper alignment, an unbalanced
coupling sheave, damaged motor bearings, or loose mounting bolts. Excessive vibration will damage
the motor bearings, brushes and commutator.

5. Listen for unusual noises, especially in the area of the bearings. Also, rubbing or rumbling noises
could be signs of internal damage. Check for loose parts on the motor such as thru bolts, hold down
bolts, bad alignment of hoods, etc. An unbalanced armature or load may also cause noise.

Note: Motors applied with rectified power supplies will often make a humming noise when operating

normally. This is even more noticeable at lower operating speeds. If you can hear a growling or
erratic hum, the power supply should be checked for proper operation and phase balance.
Improper adjustment or functioning of the power supply can cause overheating of the motor and
shorten its life.

6. At start−up, check the tightness of the main and commutating pole bolts (external on the frame) as
listed in Table 3-1. Loose pole bolts could be a source of unpleasant noise when rectified power runs
the motor.

Table 3-1 Torque Specifications for Commutating and Main Pole Bolts

Frame

180AT 3/8 - 16 24 - 30
210AT 3/8 - 16 24 - 30
250AT 3/8 - 16 24 - 30
280AT 1/2 - 13 60 - 75
320AT 1/2 - 13 60 - 75
360AT 3/8 - 16 24 - 30
400AT 3/8 - 16 24 - 30
500AT 1/2 - 13 60 - 75

Bolt Size Torque (lb-ft)

Maintenance & Troubleshooting 3-1MN605

Lubrication & Bearings Bearing grease will lose its lubricating ability over time, not suddenly. The lubricating ability

of a grease (over time) depends primarily on the type of grease, the size of the bearing, the speed at
which the bearing operates and the severity of the operating conditions. Good results can be obtained if
the following recommendations are used in your maintenance program.

Type of Grease A high grade ball or roller bearing grease should be used. Recommended grease for standard

service conditions is Polyrex EM (Mobil).

Equivalent and compatible greases include:
Texaco Polystar, Rykon Premium #2, Pennzoil Pen 2 Lube and Chevron SRI−2.

− Maximum operating temperature for standard motors = 110° C.

− Shut−down temperature in case of a malfunction = 115° C.

Lubrication Intervals Recommended lubrication intervals are shown in Table 3-2. It is important to realize that the

recommended intervals of Table 3-2 are based on average use.

Refer to additional information contained in Tables 3-3 and 3-4.

Table 3-2 Lubrication Intervals *

Base Speed - RPM

NEMA / (IEC) Frame Size

Up to 210 incl. (132) 5500 Hrs. 12000 Hrs. 18000 Hrs. 22000 Hrs.
Over 210 to 280 incl. (180) 3600 Hrs. 9500 Hrs. 15000 Hrs. 18000 Hrs.
Over 280 to 360 incl. (225) * 2200 Hrs. 7400 Hrs. 12000 Hrs. 15000 Hrs.
Over 360 to 500 incl. (300) *2200 Hrs. 3500 Hrs. 7400 Hrs. 10500 Hrs.

* Lubrication intervals are for ball bearings. For roller bearings, divide the listed lubrication interval by 2.

>2500 1750 1150 <800

Table 3-3 Service Conditions

Severity of Service

Standard 40° C Clean, Little Corrosion Deep Groove Ball Bearing

Severe 50° C Moderate dirt, Corrosion Ball Thrust, Roller

Extreme >50° C* or

Low Temperature <-30° C ** All Bearings

* Special high temperature grease is recommended (Dow Corning DC44). Note that Dow Corning DC44 grease does

not mix with other grease types. Thoroughly clean bearing & cavity before adding grease.

** Special low temperature grease is recommended (Aeroshell 7). Different brushes may also be required.

Contact your local Baldor district office or an authorized Baldor service center for technical assistance.

Ambient Temperature

Maximum

Class H Insulation

Table 3-4 Lubrication Interval Multiplier

Severity of Service

Standard 1.0

Severe 0.5

Extreme 0.1

Low Temperature 1.0

Atmospheric

Contamination

Severe dirt, Abrasive dust,

Corrosion

Multiplier

Type of Bearing

All Bearings

3-2 Maintenance & Troubleshooting MN605

Table 3-5 Bearings Sizes and Types

Frame Size

NEMA (IEC)

(These are the “Large” bearings (Shaft End) in each frame size)

Bearing OD

D mm

Bearing Description

Width
B mm

Weight of
Grease to

oz (Grams)

add *

Volume of grease

to be added

3

in

Up to 210 incl. (132) 6307 80 21 0.30 (8.4 ) 0.6 2.0
Over 210 to 280 incl. (180) 6311 120 29 0.61 (17 ) 1.2 3.9
Over 280 to 360 incl. (225) 6313 140 33 0.81 (23 ) 1.5 5.2
Over 360 to 500 incl. (300) NU319 200 45 2.12 (60) 4.1 13.4

* Weight in grams = .005 DB

Lubrication Procedure Be sure that the grease you are adding to the motor is compatible with the grease already

in the motor. Consult your Baldor distributor or an authorized service center if a grease other than the
recommended type is to be used.

Caution: To avoid damage to motor bearings, grease must be kept free of dirt. For an extremely dirty

environment, contact your Baldor distributor or an authorized Baldor Service Center for additional
information.

With Grease Outlet Plug

1. Clean all grease fittings.

2. Remove grease outlet plug.

3. If motor is stopped, add the recommended amount of grease.
If motor is to be greased while running, a slightly greater quantity of grease will have to be added.

Add grease slowly until new grease appears at shaft hole in the endplate or purge outlet plug.

4. Re-install grease outlet plug.

Without Grease Outlet Plug

1. Disassemble motor.

2. Add recommended amount of grease to bearing and bearing cavity. (Bearing should be about 1/3 full
of grease and outboard bearing cavity should be about 1/2 full of grease.)

Note: Bearing is 1/3 full when only one side of bearing is completely full of grease.

3. Assemble motor.

Sample Lubrication Determination

Assume - NEMA 286T (IEC 180), 1750 RPM motor driving an exhaust fan in an ambient temperature of
43° C and the atmosphere is moderately corrosive.

1. Table 3-2 list 9500 hours for standard conditions.

2. Table 3-3 classifies severity of service as “Severe”.

3. Table 3-4 lists a multiplier value of 0.5 for Severe conditions.

3

4. Table 3-5 shows that 1.2 in

or 3.9 teaspoon of grease is to be added.

Note: Smaller bearings in size category may require reduced amounts of grease.

tea-

spoon

Maintenance & Troubleshooting 3-3MN605

Brush Replacement Do not change brush grades or suppliers without first contacting Baldor for technical

assistance.

Brush life will vary greatly due to motor load conditions and the operating environment. The brush pigtail
leads should be checked for secure connection to the brush support stud. Brushes should be replaced
when their pigtails touch the top of the brush holder.

When replacing brushes, proper seating is important!

1. Wrap a strip of coarse grit (60) sandpaper, rough side out, around the commutator and under the
brush holder. (Do not use metal oxide based sandpaper or emery cloth that contains electrically
conductive materials).

2. Slide the new brush into the holder and snap the spring clip in place.

3. Rotate the armature slowly in the direction of normal motor rotation.

4. Remove the brush and inspect the face. The brush should be seated over 90% of the face area and
completely seated from leading to trailing edge.

Brushes should move freely in their holders. If brushes stick, it is usually due to built up dirt and oil.
Brushes should be inspected on occasion to see that they are long enough to press firmly against the
commutator. Brush springs should have equal tension. Only brushes of the same size, grade and shape
as those originally supplied should be used.

All motors have their brushes set on neutral before leaving Baldor’s factory. After replacing the brush
holder, realign it to the factory neutral mark.

When replacing a turned-down commutator in the motor with a new commutator, the brush holder
assembly must be adjusted. Keep
commutator. The brush holder assembly is designed with a nut/bolt guide assembly for ease in
positioning of the brush-box.

During periodic inspections, check that electrical connections are tight and properly insulated.

1

/16″ clearance between the bottom of the brush holder and

Brush Springs Brush springs should be inspected for proper tension during brush replacement. If the spring shows

a loss in tension, it should be replaced. Routine replacement of brush springs is recommended with
every third set of brushes.

Poor Brush Life Poor brush life may be caused by overloading, brushes operating at higher than their rated speed, or

very light electrical loads. These can be corrected by using a brush with greater current-carrying capacity
for overloads. Friction-reducing treatments reduce wear on high speed applications. Where light loading is
the cause, the answer may be to remove some brushes from the motor (with multiple brushes per pole).
Another is to install brushes with a higher content of graphite that can handle the lower current and still
film properly. Poor brush life is generally not related to the “softness” or “hardness” of the brush.

Do not change brush grades or the number of brushes per pole. Doing so may void the warranty and
make the motor unsafe to operate. Contact your local Baldor district office or an authorized Baldor
service center for technical assistance.

Brush Chatter or Bounce Brush chatter or bouncing can be caused by vibration from an external source. This may

be a bad gearbox coupling or condition, or insecure mounting of the motor. Stronger carbon grades are
available that provide more capacity for the brush to resist vibration. It is always best to fix the cause of
the problem.

Brush Sparking Excessive sparking of brushes may be due to electrical causes such as an overload or a very

unstable DC power supply. Mechanical causes include a flat spot on the commutator or external vibration.
Changing to a better brush grade, or a split-brush design may be required.

3-4 Maintenance & Troubleshooting MN605

Carbon Brushes For Special Operating Conditions

Sometimes, there are problems if motor operation requires a different design or grade of carbon brush
than what was installed when the motor was built. These special operating conditions include long periods
of operation with loads that are significantly greater or less than rated load capacity. Also, operation in in
the presence of certain chemicals, or extreme temperature and humidity can degrade brush performance.

Generally, poor brush life or commutator wear can occur if one or more of the above conditions exist. The
brush used doesn’t match the operating conditions.

Baldor offers optional brush grades for the above conditions and has replacement brushes available to
retrofit motors. Contact your local Baldor District Office or an Authorized Baldor Service Center for
technical assistance.

Do not change brush grades or the number of brushes per pole. Doing so may void the warranty and
make the motor unsafe. Contact your local Baldor district office or an authorized Baldor service center for
technical assistance.

Authorized Service Baldor catalog 505 (and the Baldor CD−ROM) lists service shops authorized to service Baldor

DC motors. Contact your local Baldor District Office for more information.

Humidity And Brush WearThis curve represents 2 grains of water per cubic foot of dry air or 4.6 grams per cubic

meter of dry air.

Zone of Safe Brush Operation

110

100

90

80

70

60

Danger Zone

50

Temperature Degrees F

Too Low Humidity

40

30

10 20 30 40 50 60 70 80 90 100

Percent Relative Humidity

45

40

35

30

25

20

15

10

Temperature Degrees C

5

0

Maintenance & Troubleshooting 3-5MN605

Section 1
General Information

Guide To Commutator Appearance

Light Film: Indicates good brush
performance. Light load, low humidity,
brush grades with low filming rates, or film
reducing contamination can cause lighter
color.

Streaking: Results from metal transfer to
the brush face. Light loads and/or light
spring pressure are most common causes.
Contamination can also be a contributing
factor.

Medium Film: Is the ideal commutator
condition for maximum brush and
commutator life.

Threading: Is a further development of the
streaking condition as the metal
transferred becomes work hardened and
machines into the commutator surface.
With increased loads and increased spring
pressure this condition can be avoided.

Heavy Film: Results from high load, high
humidity or heavy filming rate grades. Colors
not in the brown tones indicate contamination
resulting in high friction and high resistance.

Grooving: May result from an overly
abrasive brush grade. The more common
cause is poor electrical contact resulting in
arcing and the electrical machining of the
commutator surface. Increased spring
pressure reduces this electrical wear.

Copper Drag: Develops as the commutator
surface becomes overheated and
softened. Vibration or an abrasive grade
causes the copper to be pulled across the
slots. Increased spring pressure will
reduce commutator temperature.

Bar Edge Burning: Results from poor
commutation. Check that brush grade has
adequate voltage drop, that the brushes
are properly set on neutral and that the
interpole strength is correct.

Slot Bar Marking: Results from a fault in
the armature windings. The pattern relates
to the number of conductors per slot.

This chart courtesy of Helwig Carbon Products, Inc., Milwaukee, WI

3-6 Maintenance & Troubleshooting MN605

Section 1
General Information

Caution: Be very careful when repainting a drip proof motor. Do not get any paint on the commutator. Paint

on the commutator will show up as black marks in brush tracks. Also, excessive brush sparking
or erratic operation can be caused by paint or other material on the commutator.

Commutator After several hours of operation, the commutator surface under the brush should take on a darker bronze

color. This is due to self-generated film caused by normal commutation. This coloration should be even,
without blotches or black areas. A shiny copper color or black streaks in the brush tracks are signs of
improper commutation or contamination by a foreign material. Contact Baldor for assistance in correcting
these problems.

If the commutator becomes rough and burned, or becomes black, it should be cleaned of dirt and carbon
particles. This can be done by wiping it with a dry, lint-free cloth. Also vacuuming or blowing out the motor
with a dry air supply are suitable cleaning methods. Do not use solvents or cleaning solutions on the
commutator. To remove spots or contamination that will not wipe off, wrap a strip of coarse (60# grit)
sandpaper around the commutator. Then rotate the armature back and forth by hand. Do not use emery
cloth as this contains electrically conductive materials.

Another method of commutator resurfacing is to use a commercially available commutator dressing stone.
This should only be done by trained and experienced people. This stone should be taped or attached to
the end of a stick made of electrically insulated material. The motor should be run at about half speed and
the stone applied lightly to the commutator surface. This operation must be done with no load on the
motor.

The surface of the commutator should be smooth and round. This can be checked while the motor is
running at low speed. Press lightly on one brush with an insulated stick. Do not use a lead pencil as this
contains electrically conductive graphite. If you feel movement of the brush, it suggests a worn or
uneven commutator. The armature must be removed from the motor and the commutator machined by a
qualified repair shop.

Rapid Commutator Wear Light electrical loads and contamination are the usual causes of rapid commutator wear.

Light loading may require the removal of some brushes on motors with multiple brushes per pole.
Sometimes a low current density brush grade is used. There are also brushes that have a mild polishing
action. These prevent certain chemicals, especially chlorine and silicone, from attacking the commutator.
Brushes, are available for use in plastic extruder applications where PVC is present. Usually, you do not
have to change the design or grade of the brushes on new motors unless special operating conditions
exist.

Do not change brush grades or the number of brushes per pole. Doing so may void the warranty and
make the motor unsafe. Contact your local Baldor district office or an authorized Baldor service center for
technical assistance.

Blowers & Filters Do not use silicone RTV around DC motors as commutator surface damage can occur. Intake filters

on blowers and louvers of drip proof motors should be cleaned to remove any dust or foreign matter.
Canister type filters should be replaced when dirty. Failure to keep air intakes clear will cause overheating
and premature failure of the insulating system.

Troubleshooting

Armature Overheating Excessive overloads will cause a noticeable odor of overheated varnish or charred

insulation. The commutator may eventually become blackened and pitted and the brushes burned. This
overheating may be general and uniform. To cure, remove the overload and rewind or replace armature if
damaged beyond use.

An open-circuited armature coil will cause flashing at the commutator. Two adjacent bars will show severe
burning and a resulting overheated armature. Short-circuited coils or commutator bars may cause local
heating that could destroy the insulation at that spot. This may result in the burning of the armature coils,
banding or commutator bars.

Grounds in the armature circuit may be found by measuring the motor winding resistance. If the armature
is grounded, less than 1 meg ohm is measured.

These tests should be done by experienced and qualified personnel.

Maintenance & Troubleshooting 3-7MN605

Field Coil Overheating The blowers or external cooling systems should be left in operation if the main field

windings remain fully energized with the motor at standstill. Failure to do so may cause too much heat
build-up which could cause reduced insulation life.

When using field economy circuits to reduce voltage to the main fields during standstill, blowers do not
need to be operating. The most common failure with overheated field coils is a short in one or more of the
shunt coils.

Shorted coils show less than half the line voltage for two pole motors. This is with the fields connected for
high voltage (in series). Shorted four pole motor coils will read less than 1/4 of the line voltage with the
coils connected for high voltage (in series).

A grounded coil may cause overheating. This defect may be tested as shown by the ground test for an
armature. With brushes lifted, measure the motor winding resistance. If the armature is grounded, less
than 1 meg ohm is measured.

An open field coil on a motor will cause the armature to have no torque. The motor may run at a very high
speed at no load. The commutator may be flashing. To locate an open coil, apply line voltage to the shunt
coils (brushes lifted). A voltmeter will show no reading across a good coil. It will show about the line
voltage across the open coil.

These tests should be done by experienced and qualified personnel. If you find any of the above defects,
don’t run the motor. First contact your local Baldor District Office or an Authorized Baldor Service Center
for repairs.

Excessive Load Excessive load may be found by checking the DC armature ampere input and comparing it with the

rating on the nameplate. An excessive load may prevent the motor from starting or accelerating to full
load speed. It could finally result in premature failure of the motor or control. Be sure to use an averaging
type ammeter if the motor’s power is coming from a rectifier or SCR control.

Jogging and Repeated Starts

Repeated starts or jogs of motors may reduce the life of the brushes and winding insulation. The heat
produced by excessive starting may be more than what can be dissipated by the motor under a constant
full load conditions. If you must frequently start or jog a motor, you should check the application with the
local Baldor District Office.

Heating Duty cycle and maximum ambient temperature are shown on the nameplate of the motor. If there is any

question about safe operation, contact the local Baldor District Office.
Motor overheating may be caused by improper ventilation, excessive ambient temperature, dirty

conditions or an inoperable blower or dirty filter. Electrical causes may be due to excess current caused
by an overload or over-voltage to the fields.

Thermostat Most stock Baldor DC motors 180 frame and above have a standard temperature-sensing thermostat

mounted to their interpole winding. This normally closed thermostat opens when the temperature limit is
exceeded. Another option available is a normally open thermostat that closes with temperature.

On blower cooled or separately ventilated motors, the protection capabilities of the thermostats are
greatly reduced at low speeds. This is because the interpoles have the same amount of heat transfer
regardless of speed. Armature heat transfer is less at low speed. There is less internal air turbulence at
low speeds causing higher temperatures at the armature.

The thermal time constant for interpoles can be as much as five times longer than the armature’s time
constant. Because of this, the thermostat cannot be relied upon to protect the armature during extreme
overloads lasting a short time.

The ripple of the rectified power supply and manufacturing tolerances of mounting the device affect the
thermostat’s accuracy.

For thermostat contact ratings, refer to Thermostats in Section 2 of this manual.

3-8 Maintenance & Troubleshooting MN605

Section 1
General Information

Table 3-6

Symptom Possible Causes Possible Solutions

Motor will not start Usually caused by line trouble, such

as, single phasing at the starter.

Excessive humming High Voltage. Check input line connections.

Loose pole pieces. Torque the bolts as specified in Table 3-1.

Motor Over Heating Overload. Compare actual amps

(measured) with nameplate rating.

Improper ventilation. Check external cooling blower to be sure air is moving

Armature rubbing on stator. Check air gap clearance and bearings.

Field over voltage. Check input voltage.
Full voltage on field with motor

stopped.
Grounded winding. Perform dielectric test and repair as required.
Improper connections. Inspect all electrical connections for proper

Bearing Over Heating Misalignment. Check and align motor and driven equipment.

Excessive belt tension. Reduce belt tension to proper point for load.
Excessive end thrust. Reduce the end thrust from driven machine.
Excessive grease in bearing. Remove grease until cavity is approximately 3/4 filled.
Insufficient grease in bearing. Add grease until cavity is approximately 3/4 filled.
Dirt in bearing. Clean bearing cavity and bearing. Repack with correct

Vibration Misalignment. Check and align motor and driven equipment.

Rubbing between rotating parts and
stationary parts.

Armature out of balance. Have armature balance checked are repaired at your

Resonance. Tune system or contact your Baldor Service Center for

Noise Foreign material in air gap or

ventilation openings.

Growling or whining Bad bearing. Replace bearing. Clean all grease from cavity and new

Troubleshooting Chart

Check source of power. Check overloads, fuses,
controls, etc.

Locate and remove source of excessive friction in
motor or load.
Reduce load or replace with motor of greater capacity.

properly across cooling fins.
Check blower for proper direction of rotation.
Check motor brush covers to ensure they are solid on
the commutator end and that they are not louvered.
Check filter for dirt, clean or replace.
Excessive dirt build-up on motor. Clean motor.

Tighten “Thru Bolts” that hold the endplates to frame.
Torque the pole bolts as specified in Table 3-1.

Reduce field voltage to 60% with field economy circuit
in the control.

termination, clearance, mechanical strength and
electrical continuity. Refer to connection diagram.

grease until cavity is approximately

Isolate and eliminate cause of rubbing.

Baldor Service Center.

assistance.
Remove armature and foreign material. Reinstall

armature. Check insulation integrity. Clean ventilation
openings.

bearing. Repack with correct grease until cavity is
approximately

3

/4 filled.

3

/4 filled.

Maintenance & Troubleshooting 3-9MN605

Accessories The following list shows some accessories available through Baldor’s Mod Express or available on

custom manufactured motors. Contact your Baldor supplier for information on each additional accessory
or those listed below.

Bearing RTD

RTD (Resistance Temperature Detector) devices are used to measure or monitor the temperature of
the motor bearing during operation.

Bearing Thermocouples

Used to measure or monitor bearing temperatures.

Bearing Thermostat

Temperature device that activates when bearing temperatures are excessive. Used with an external
circuit to warn of excessive bearing temperature or to shut down a motor.

Blowers with Filters:

Available to increase the constant torque speed range of DPFG motors. This increases the
continuous operating torque range at low speeds.

Brush Wear Indicator:

Provides a warning when the brushes have worn down to the level where they need to be replaced
(before damage to the commutator).

Condensation Drains & Breathers:

Stainless steel drains and separate breathers are available.

Conduit Boxes

Optional conduit boxes are available in various sizes to accommodate accessory devices.

Cord & Plug Assembly

Adds a line cord and plug for portable applications.

Drip Covers

Designed for use when motor is mounted in a vertical position. Contact your Baldor distributor to
confirm that the motor is designed for vertical mounting.

Fan Cover & Lint Screen

To prevent build-up of debris on the cooling fan.

Nameplate

Additional stainless steel nameplates are available.

Roller Bearings

Recommended for belt drive applications with a speed of 1800 RPM or less.

Rotation Arrow Labels

Rotation arrows are supplied on motors designed to operate in one direction only. Additional rotation
arrows are available.

Slide Bases:

Allows easy belt adjustment while maintaining correct pulley and belt alignment.

Space Heater

Added to prevent condensation of moisture within the motor enclosure during periods of shut down or
storage.

Stainless Hardware

Stainless steel hardware is available. Standard hardware is corrosion resistant zinc plated steel.

Tachometers:

DC, AC and digital outputs are available. These can be mounted to our motors or shipped separately.
Tachs help the SCR control achieve more precise speed regulation than by armature feedback alone.

Transparent Brush Inspection:

For easy brush inspection and commutation monitoring without disassembly of the motor.

Winding RTD

RTD (Resistance Temperature Detector) devices are used to measure or monitor the temperature of
the motor winding during operation.

Winding Thermocouples

Used to measure or monitor winding temperatures.

Winding Thermostat

Temperature device that activates when winding temperatures are excessive. Used with an external
circuit to warn of excessive winding temperature or to shut down a motor.

3-10 Maintenance & Troubleshooting MN605

Reflash Instructions Instructions to reflash the residual magnetism for Lifting Magnet Generators only.

These generators are self−exciting. If voltage will not build up, it is possible the residual magnetism is
insufficient to initiate excitation. This procedure is to restore sufficient residual magnetism to self excite.

Note: Loss of residual magnetism can be caused by misconnection (reversing the connections) of F1 and

F4.

1. Disconnect F1 and F4. All other leads may remain connected.

2. Connect 24 to 40VDC power source positive lead to F1 and negative to F4.
DC source may be batteries, a DC welder (not AC) or rectified AC.

3. Drive generator at rated RPM.

4. Measure the voltage across A1 and A2. Voltage should be 150 to 200% of F1 to F4 voltage. When
A1 to A2 voltage level reaches this level (approximately 30 seconds) carefully remove the source
leads, an arc may be present during disconnect.

5. Stop the generator.

6. Reconnect F1 and F4 as shown in the DC Generator Connection Diagram. Rotation is viewed from
opposite drive end (commutator end) A1 is positive for CCW rotation. A2 is positive for CW rotation.
S1 is always negative.

DC Generator Connection Diagram

Shunt Fields

Compound Wound Short Shunt Connection

Series Field

ARM

COMM Field

Shown for CCW (counterclockwise) rotation, (viewed from opposite drive end or
commutator end). For CW (clockwise) rotation, interchange leads A1 and A2.

Maintenance & Troubleshooting 3-11MN605

3-12 Maintenance & Troubleshooting MN605

Section 4
Connection Diagrams

Low Voltage connection Shunt Field

F1

F3

Interpole

Armature

A1

+

F2

F4

A2 S2S1

Series Motor CCW Rotation
(Facing Commutator End)

Shunt Field

F2

F3

F1

Field Reversing Series Motor

Series Field

−

Armature Reversing

Compound and Stabilized Motors

High Voltage connection Shunt Field

F2

Armature

A1

+

F3

Interpole

A2 S1S2

Series Motor CW Rotation
(Facing Commutator End)

Shunt Field

F2

F3

F4

Series Field

−

Interpole Series Field

Armature

F1

A1

+

A2 S2S1

Compound or Stabilized Shunt Motor
CCW Rotation (Facing Commutator End)
High Voltage Field Connection

Interpole Series Field

Armature

F4 A1

− −

F1

A2

+

S2S1

Compound or Stabilized Shunt Motor
CW Rotation (Facing Commutator End)
High Voltage Field Connection

F4

Connection Diagrams 4-1MN605

Field Reversing Shunt Motor

Shunt Field

F2

F3

Interpole

Armature

F1

A1

+

Shunt Motor CCW Rotation
(Facing Commutator End)
High Voltage Field Connection

Field Reversing Shunt Motor

Shunt Field

F3

F2

Interpole

Armature

F4

A1

+

Shunt Motor CW Rotation
(Facing Commutator End)
High Voltage Field Connection

DC Generator Connection Diagram

Compound Wound Short Shunt Connection

A2

A2

F4

−

F1

−

Shunt Field

F1

Rheostat

A1

+

F2 F3 F4

Comm. Field

CCW Rotation

A2

Series Field

S2 S1

−

(Facing Commutator End)
For CW Rotation, Interchange Leads A1 and A2.

4-2 Connection Diagrams MN605

Baldor District Offices

BALDOR ELECTRIC COMPANY

World Headquarters

P.O. Box 2400 Fort Smith, AR 72901−2400

(479) 646−4711 Fax (479) 648−5792

www.baldor.com

© 2009 Baldor Electric Company
MN605

All rights reserved. Printed in USA

2/09