Siemens 680 User Manual

Installation
Induction Motors/
Operation Maintenance
Generators
Horizontal - Medallion
500, 580, 680, 800, 1120 Frames TEWAC & TEAAC Enclosures
Types CGG, NCGG, CAZ
ANIM-03521-0110 (New Issue) ©2010 Siemens Industry, Inc. All rights reserved.

Table of Contents

Page Page TABLE OF CONTENTS 1 OPERATION 10 SAFETY PROCEDURE 2 INTRODUCTION 3
Warranty 3 Normal Operation 10 Receiving 3 Voltage/Frequency Variation 10 Handling 4 Trouble Shooting 11 Temporary Storage 4 Type Designations 4 Preventive Maintenance 13 Ventilation 4 Inspection 13
INSTALLATION 5
Motor Dimensions 5 Rotor Cleaning 15 Location 5 Stator Cleaning 15 Foundation 5 Insulation Resistance 16 Mounting 5 Drying Insulation 16 Coupling of Sleeve Bearing Motors 5 Bearings 17 External Wiring 6 Bearing Lubrication 20 Changing Direction of Rotation 6 Bearing Replacement 22 Alignment 6 Hot Alignment 7 Identification Vibration 8 Doweling 8 Force Feed Lubrication 8 Typical Motor Control Settings 9
Note - These instructions do not purport to cover all 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 user’s purposes, the matter should be referred to the local Siemens Sales Office. The contents of this instruction manual shall not become part of or modify any prior or existing agreement, commitment or relationship. The sales contract contains the entire obligation of Siemens. The warranty contained in the contract between the parties is the sole warranty of Siemens. Any statements contained herein do not create new warranties or modify the existing warranty.
Siemens machines are built in accordance with the latest applicable revision of the National Electric Code, Underwriters Laboratories Standards and Procedures, and NEMA (National Electrical Manufacturers Association) Standards. These publications and this instruction manual should be thoroughly read and understood prior to beginning any work on this equipment.
The information contained within is intended to assist operating personnel by providing information on the general characteristics of the purchased equipment. It does not relieve the user of the responsibility of using accepted engineering practices in the installation, operation and maintenance of this equipment.
Should a conflict arise between the general information in this manual and the contents of the drawings and supplementary material, the latter shall take precedence.
The illustrations in this book show typical machines. Special features deviate from those pictured.
Initial Start 10 Oil Circulating Systems 10
MAINTENANCE 13
Corrective Maintenance 15
SPARE PARTS 26
26 MOTOR SERVICE RECORD 34 VIBRATION ANALYSIS SHEET 35 NOTES 36
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Safety Procedures
This equipment contains hazardous voltages. Death, serious personal injury or property damage can result if safety instructions are not followed.
The successful and safe operation of motors and generators is dependent upon proper handling, installation, operation and maintenance, as well as upon proper design and manufacture. Failure to follow certain fundamental installation and maintenance requirements may lead to personal injury and the failure and loss of the motor as well as damage to other property.
Only qualified personnel should work on or around this equipment after becoming thoroughly familiar with all warnings, safety notices and maintenance procedures contained herein. Only qualified personnel should be involved in the inspection, maintenance and repair procedure and all plant safety procedures must be observed.
Qualified Person: For the purpose of this manual and product labels, a Qualified person is one who is familiar with the installation, construction and operation of the equipment, and the hazards involved. In addition, he or she has the following qualifications:
a. Is trained and authorized to energize, de-energize,
clear, ground and tag circuits and equipment in accordance with established safety practices.
b. Is trained in the proper care and use of protective
equipment, such as rubber gloves, hard hat, safety glasses, face shields, flash clothing, etc., in accordance with established safety practices.
c. Is trained in rendering first aid.
Danger: For the purpose of this manual and product labels, Danger indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
Warning: For the purpose of this manual and product labels, Warning indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.
Caution: For the purpose of this manual and product labels, Caution indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury. It is also used to alert against unsafe practices.
Motors should be installed and grounded per local and national codes.
Do not operate this equipment in excess of the values given on nameplate or contrary to the instructions contained in this manual. The equipment (or a prototype) has been factory tested and found satisfactory for the condition for which it was sold. Operating in excess of these conditions can cause stresses and strains beyond design limitations. Failure to heed this warning may result in equipment damage and possible personal injury.
DANGER
Hazardous voltage.
Will cause death, serious injury, electrocution or property damage.
Disconnect all power before working on this equipment.
NOTE
Squirrel cage induction machines can be driven by various types of prime movers. These will act as induction generators. This instruction manual applies to both motors and induction generators. However, for clarity reasons, the machine will be referred to as a “motor”.
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Introduction

DANGER
Hazardous voltage.
Will cause death, serious injury, electrocution or property damage.
Disconnect all power before working on this equipment.
These instructions present general recommendations for installation, operation and maintenance of induction motors built at the Norwood plant. If additional information is required, contact Siemens Industry.

Warranty

See your sales contract for warranty coverage. Documentation of storage maintenance, alignment and regreasing may be required for certain warranty considerations.

Receiving

Motors are shipped in first class condition. They have been inspected and are skidded to prevent damage from ordinary handling during shipment.
Inspect new motors for shipping invoice. Make the examination before removing from cars or trucks. If damage or indication of rough handling is evident, file a claim with the carrier at once, and notify your Siemens sales representative.
Remove only the shipping invoice. Do not remove tags pertaining to lubrication, operation and storage instructions. Read and follow all instructions to insure that no damage to motor bearings, (due to condensation) and motor windings occurs during storage.
Use care in handling. Dropping the motor or otherwise imposing shock loads can cause unseen and undetected damage to bearings. This damage such as false brinelling of the races of anti-friction bearings can result in early bearing failure.
If supplied, energize space heaters to help prevent condensation within the motor enclosure.
Motors having sleeve bearings or oil lubricated antifriction bearings are shipped WITHOUT OIL in the bearing reservoir. These bearings and journal surfaces are protected during shipment by a temporary film of rust inhibiting oil or, when a motor is supplied specifically with “provisions for oil mist furnished by the user), the motor is shipped from the factory with grease in the bearings.
lubrication” (oil supply system
When receiving a motor with sleeve bearings:
1. Remove shaft blocking materials.
2. Visually inspect bearing condition through sight glass and bearing drain opening.
3. Check for moisture accumulation. Remove any traces of oxidation before putting the motor into service.
4. Fill bearing reservoirs to normal level with a high grade industrial lubricating oil. See Maintenance Section of this instruction book to determine proper oil level.
5. Rotate the shaft a minimum of 10 complete turns by hand to distribute oil over bearing parts. Make sure the oil rings in each bearing rotate freely.
When receiving a motor with grease lubricated anti­friction bearings:
Motors having grease lubricated antifriction bearings are shipped with the bearings already lubricated and ready for operation.
If the elapsed time from the time of shipment to the time in which the unit is to be started is in excess of three (3) months, regrease per the lubrication plate mounted on the motor.
When receiving a motor with oil mist lubricated anti­friction bearings:
1. Be sure that the motor is not stored outdoors.
2. Be sure that the oil mist lubrication is connected and operating before starting the motor.
3. The oil mist lubrication should be in operation within two weeks after the motor is received from the factory.
When receiving a motor with “provisions for oil mist lubrication”:
1. Leave the grease in the bearings if the motor is to be stored.
2. Before operating the motor with oil mist lubrication, disassemble the motor, and clean the grease from bearings, end caps, and the bearing housing cavities with a suitable solvent.
WARNING
Heavy equipment.
Improper handling may cause death, serious injury or property damage.
Check lifting devices before lifting. Use proper slings, chains and spreaders.
Note any warning plates on motor and follow instructions on each plate.
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Introduction

Handling

Lifting devices are provided for handling only. An experienced rigger should be used to install motors.
To avoid damage, the use of spreader bars is recommended on other than single point lifts. Lifting devices are provided to facilitate handling with shackles and cables. Avoid pounding or bumping shaft, coupling or bearing parts, as shocks may damage bearings.
NOTE WEIGHT BEFORE LIFTING. The weight is indicated on the outline drawing. Apply tension gradually to cables. Do not jerk or attempt to move the unit suddenly.
Motor Weights (in pounds)
Frame Size Minimum Maximum
500 2300 5400 580 4300 8400 680 10000 20000 800 15000 31000
1120 26000 37000

Temporary Storage

If the equipment is not to be installed and operated soon after arrival, store it in a clean, dry, well- ventilated place, free from vibration and rapid or wide variations in temperature. Rotate the shaft a minimum of 10 complete turns by hand each month to coat the bearings with lubricant which will retard oxidation or corrosion, and prevent possible false brinelling. If drain plugs are provided in enclosed motors, they must be removed periodically to drain any water accumulation from the motor. Consider a unit in storage when:
1. It has been delivered to the job site and is awaiting installation.
2. It has been installed but operation is delayed over 30 days pending completion of plant construction.
3. There are long (30 day) periods between operating cycles.
4. The plant (or department) is shut down for 30 days.
NOTE
Storage requirements vary, depending on the length of storage and the climate. For storage periods of three months or longer or climate variations, consult Siemens Storage Recommendations ANIM-03114. Storage maintenance is to be documented for warranty information.

Type Designations

The motor type designation consists of a basic letter or letters indicating the motor enclosure type to which other letters may be added denoting modifications.
Motor Type Motor Enclosure
CGG or NCGG
CAZ
Totally Enclosed
Water to Air Cooled
Totally Enclosed Air to Air Cooled

Ventilation

Type CGG, NCGG – 500 Frame and Type CGG – 580, 680, 800 & 1120 Frame
The heated internal air from the hot stator core is directed to an internally mounted heat exchanger where it is cooled and recirculated back into the motor in a closed cooling loop. The cooled internal air enters the motor from the heat exchanger and non-metallic air baffles direct the air to an internal rotor fan that circulates it through the rotor core, around the coil ends, into the air gap, and through the vent ducts in the rotor and stator cores. Heated air is exhausted through internal openings in both sides of the motor and is directed to the heat exchanger in the motor top cover. The hot internal air is circulated over the finned surface of the heat exchanger. A steady flow of cooling water provided by the customer enters and exits the heat exchanger. Refer to motor outline drawing for specific water inlet and outlet locations.
Type CAZ – 580, 680, & 800 Frame
The heated internal air from the hot stator core is directed to an internally mounted heat exchanger where it is cooled and recirculated back into the motor in a closed cooling loop. The cooled internal air enters the motor from the heat exchanger and non-metallic air baffles direct the air to an internal rotor fan that circulates it through the rotor core, around the coil ends, into the air gap, and through the vent ducts in the rotor and stator cores. Heated air is exhausted through internal openings in both sides of the motor and is directed to the heat exchanger in the motor top cover. The hot internal air is circulated over a series of cooling tubes in the heat exchanger. A steady flow of cool ambient air is blown through the cooling tubes by a shaft mounted external fan or an auxiliary blower mounted on the heat exchanger. Refer to motor outline drawing for specific air intake and exhaust locations.
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Installation

Motor Dimensions

For motors built in the frame sizes covered by this manual, the letter dimensions have the same definitions as established NEMA standards. Established dimensions for these frames may be found on catalog sheets or certified drawings.
CAUTION
Damp Location.
Can cause property damage if equipment is operated intermittently.
Use space heaters to prevent dampness. Grease machine fits when unit is reassembled to prevent corrosion.

Location

Before pouring, locate foundation bolts by use of template frame and provide secure anchorage (not rigid). It is recommended that a fabricated steel base be used between motor feet and foundation. See certified drawings of motor, base, and driven unit for exact location of foundation bolts. Allow for grouting base when pouring. Cast the base footpads level and in the same plane.

Mounting

Mount the motor base (if used) on foundation or other support. Shim as required to level. Use laser or spirit level (check two directions at 90 will be in one plane (base not warped) when base bolts are tightened. Set motor on the base, install nuts and tighten.
DO NOT TIGHTEN UNTIL AFTER ALIGNMENT.
o
) to insure motor feet
Select a location for the motor and driven unit that will:
1. Be clean, dry, well ventilated, properly drained, and provide accessibility for inspection, lubrication and maintenance. Outdoor installations may require protection from the elements.
2. Provide adequate space for motor removal without shifting the driven unit.
3. Permit the motor to safely deliver adequate power. Temperature rise of a standard motor is based on operation at an altitude not higher than 3,300 feet above sea level.
4. Avoid condensation of moisture in bearings and on windings. Motors should not be stored or operated in areas subject to rapid temperature changes unless motors are energized or protected with space heaters.

Foundation

Concrete (reinforced as required) makes the best foundation, particularly for large motors and driven units. In sufficient mass it provides rigid support that minimizes deflection and vibration. It may be located on soil, structural steel, or building floors provided the total weight (motor, driven unit, foundation) does not exceed the allowable bearing load of the support.
Allowable bearing loads of structural steel and floors can be obtained from engineering handbooks. Building codes of local communities give the recommended allowable bearing loads for different types of soil. For rough calculation the foundation should be approximately 2-1/2 times total unit weight.
NOTE
Experience has shown that any base-mounted assemblies of motor and driven units temporarily aligned at the factory may twist during shipment. Therefore, alignment must be checked after mounting. Realignment is to be documented for warranty information.

Coupling of Sleeve Bearing Motors

Sleeve bearings cannot withstand externally generated axial thrust. Antifriction bearings are normally designed to handle a minimum thrust. As the motor and driven equipment get hot they may expand towards each other and with the wrong coupling this could produce an axial force. Therefore, the selection of coupling is of extreme importance. If properly installed, the following types of couplings are considered to be free from the development of axial thrust and may be used:
1. Laminated Metal Disk Type
2. Rubber Biscuit Type (Designed for the Speed)
Limited end float models of the following types are available from several coupling manufacturers and may be used by selecting the proper end float (See “End Float – Sleeve Bearings” under Bearing Replacement)
3. Pin and Bushing Type
4. Gear Type
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Installation

External Wiring

DANGER
Hazardous voltage.
Will cause death, serious injury, electrocution or property damage.
Disconnect all power before working on this equipment.
NOTE
Before running motor, see Initial Start.
Starting and overload control devices must be matched to motor rating. For safety or convenience they may need to be installed some distance from the motor. Follow the control manufacturer’s instructions to make proper installations and connections. Observe the following:
1. Connect electrical power supply to conform with National Electric Code and any local regulations. Line voltage and wire capacity must match motor rating stamped on the nameplate.
2. With the driven equipment disconnected, momentarily energize the motor to check rotation.
3. If motor is three-phase type, reverse rotation (if required) by interchanging any two of the three power leads.

Changing Direction of Rotation

Look for rotation plates usually mounted on opposite drive end of the motor.
CAUTION
Excessive heat.
Motor may overheat if motor cooling fans run in the wrong direction.
Run motor in direction shown on motor or change fans.
The internal rotor fan direction must be considered if changing direction of rotation. See the following Internal Rotor Cooling Fan table to identify which motors have directional fans.
In addition, for Type CAZ motors with shaft mounted external cooling fan, the fan is directional and must be replaced with a fan designed for the desired direction of rotation.
Motor Speed
(No. of poles)
Rotor Material Aluminum Copper Aluminum Copper
500, 580
Frames
680, 800
Frames
1120 Frame N/A N/A N/A 2
1. Inspect rotor to determine whether alternative A or B below applies;
2. Replace single directional rotor fan with one for the opposite direction.
3. Fans are bi-directional which allows motor rotation in either direction without mechanical modification.
4. The single directional rotor fans must be interchanged end-for-end.
Internal Rotor Cooling Fan
3600 – 3000 RPM
(2 pole)
1 4 3 3
N/A 4 N/A 3
A. If the rotor has integrally cast directional fans,
either rotor machining instructions and conversion parts can be purchased from the factory or the rotor core may be removed from the shaft, switched end-for-end, and remounted on the shaft.
B. If the rotor has shaft-mounted directional fans,
the fans must be interchanged end-for-end.
1800 RPM & Slower
(4 or more poles)
NOTE
It will be necessary to rebalance the rotor if the fans are changed.

Alignment

Accurate shaft alignment between motor and driven equipment is essential. Improper alignment may result in vibration, bearing overloads and excessive shaft stresses. Flexible couplings will not compensate for excessive misalignment.
NOTE
A basic rule is to not have more than five shims in a shim pack under any one motor foot. Thick shim packs consisting of many thin shims will cause soft foot, excessive vibration or twisted frame (motor foot out of plane).
Parallel Alignment
After positioning unit for correct end float, separate the coupling halves and mount a dial indicator rigidly on one coupling half with the button on the cylindrical surface of the other half. Rotate the shafts together, and take readings at top, bottom and side positions. Align shaft so difference between top and bottom readings and the side readings is a maximum of
0.002 inch for a flexible coupling.
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Installation
Angular Alignment
Hold each shaft at maximum end float. Rotate both shafts together, and measure between matching points at the outside diameter of the coupling faces for the top, bottom and both sides. Use two indicators because of possible axial shaft movement. Read difference of variation between them.
Align shafts so that the total indicator variation does not exceed 0.002 inch. (See Figure 1.)
NOTE
If vibration levels increase cold to hot, alignment should be checked hot to verify that motor and driven equipment are properly aligned at operating temperature. Adjust if necessary.
3. If no change is indicated, retighten the bolt and repeat the process for each of the remaining three mounting bolts.
4. If a change is indicated, add shims under motor foot and retighten until indicator movement is reduced or eliminated.
NOTE
1. The foot plane is of concern for each unit of rotating equipment. Check driven equipment if necessary.
2. Base or foundation rigidity can also affect vibration; check for resonance in supporting structure.
3. Recheck alignment after any change in shims and document alignment readings for warranty information.
V-Belts
Check belt manufacturer’s recommendations for maximum speed of sheaves and belts, minimum pitch diameters, maximum allowable number of belts and maximum sheave width.
When motor is ordered for V-belt drive, check motor outline for motor manufacturer’s limits on belt pull, sheave distance from motor, and sheave diameter.
Use only matched-belt sets. V-grooves must be in line; sheaves must be parallel and axially aligned. Belts must enter and leave sheaves with no side bending. For long bearing life, the belt tension is important; consult belt manufacturer for proper tension to suit drive. Protect belts from grease and oil. NEVER use belt dressing.

Hot Alignment

Figure 1. Diagrams Showing Parallel and
Angular Misalignment
Foot Plane
The proper foot plane exists when adequate shims have been installed to assure equal pressure on each foot or corner of motor when the mounting bolts are loose.
To determine proper foot plane:
1. Mount dial indicator on shaft to be checked so that contact will rest on either the adjacent shaft or a bracket from the foundation or base.
2. With mounting bolts tight and indicator set at zero, release one bolt at the shaft extension end of the unit and check indicator for a maximum change of 0.001 inch.
It is possible for the motor shaft height to change relative to the driven equipment and this should be compensated for during the alignment procedure. Heat from driven equipment can also cause horizontal misalignment.
WARNING
Rotating parts.
Can cause serious injury.
Disconnect and lock out power before working on equipment.
If motor application is abnormal (high temperature, extreme vibration, etc.) consult the factory for special instructions or additional information.
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Installation
Check for vertical alignment (parallelism) of coupled drive as follows:
1. Operate unit until normal temperature is reached (may require several hours).
2. Shut down motor and lock out switch.
3. Mount dial indicator as in Figure 2.
4. Rotate shaft, noting readings at 0°, 90°, 180°, and 270° (both sides, top, and bottom). If within 0.002 inch total indicator reading, or other limit specified by the factory, unit is satisfactory for operation.
5. If not within limits, add or remove shims as required to raise or lower motor.
6. If shims are changed for high temperature operation, repeat alignment procedure to extent necessary to assure proper alignment. Document readings for warranty information.
Figure 2. Check of Vertical Alignment

Vibration

Completing Mechanical Installation
After controlling rotor end float and establishing accurate alignment, it is recommended to drill and ream the foundation plate and motor feet together for dowel pins. (See Doweling).
Recheck parallel and angular alignment before bolting the coupling together. Motor shaft should be level within 0.03 inch after alignment.

Doweling

Doweling the motor (and driven unit) accomplishes the following:
1. Restricts movement.
2. Eases realignment if motor is removed from base.
3. Temporarily restrains the motor, should mounting bolts loosen.
Inserting Dowel Pins
The following procedure is recommended:
a. Check the alignment after the unit has been in
operation approximately one week. Correct as necessary.
b. Using pre-drilled dowel holes in motor feet as
guides, drill into the mounting base.
c. Ream holes in the feet and base to the proper
diameter for tapered dowel pins. Clean out the chips.
d. Insert dowel pins.

Force Feed Lubrication

The standard unfiltered housing vibration limits measured at no load, uncoupled, and with rigid mounting are as follows based on the requirements of NEMA MG1-7.8.
Speed Velocity, inches/sec peak
1200 – 3600 RPM 0.120
1000 RPM 0.105
900 RPM 0.096 750 RPM 0.079 720 RPM 0.075 600 RPM 0.063
After alignment is complete and foot mounting bolts are tight, run motor at no load (or minimum possible). Check for vibration. If excessive vibration exists and the alignment is acceptable, check foot plane by loosening one drive end-mounting bolt at a time as detailed below. This is to be documented for warranty information. When resiliently mounted, allowed levels are 25% higher.
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If force feed lubrication is used, flush lubrication lines thoroughly to make sure the lines are clean before connecting lines to bearing housings. Be sure that bearing cavities are filled with oil to the proper level before starting. See motor outline drawing to determine proper oil level. Be sure that proper oil pressure and flow are provided by the supply system. Verify that the oil drain flow agrees with the factory requirements. The orientation and size of oil drain piping supplied with the motor must not be altered. Oil drain piping should be of the same size or larger from the motor piping to the oil sump. Piping must slope downward. Pressure build up in the drain line between the oil sump and the motor bearing housing can lead to oil leakage. Document readings for warranty information.
Installation

Typical Motor Control Settings

Winding Temperature
Class B Insulation
Class F Insulation
Alarm
130°C 155°C
Motor Bearing Temperature (Thermocouple or RTD’s)
Sleeve Bearing
Antifriction Bearing
100°C 105°C
100°C 105°C
(2)
Ground Fault
4 Amps
Primary
Circuit
Instantaneous Overcurrent
With ½ Cycle Delay
Without Time Delay
1.8 times Locked Rotor Amps
2.4 times Locked Rotor Amps
Maximum Voltage 110 % of Rated Voltage 10 sec. Minimum Voltage (the minimum voltage
also applies to starting unless otherwise specified)
90 % of Rated Voltage 10 sec.
Maximum Frequency Deviation ±5% 10 sec.
Trip
(Shutdown)
155°C 170°C
8 Amps
(2)
Primary
Circuit
Timer Trip
Setting
(1)
(2)
(2)
0.2 sec.
(2)
Maximum of Voltage Plus Frequency Deviation ±10% 10 sec.
Maximum Voltage Unbalance
Maximum Current Unbalance
(3)
1% 15 sec.
(3)
8% 15 sec.
Suggested Vibration Limits
RPM 3600 1800 1200 900 and
Slower Shaft (mils, pk-to-pk) 3.3 3.7 4.3 5.0 Housing (in./sec.) 0.25 0.25 0.25 0.25
(1)
Maximum time at maximum condition before control device is to operate.
(2)
Increase as necessary to avoid nuisance trips.
(3)
This is the maximum deviation from the average of the three phases.
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Operation

Initial Start

CAUTION
Do not exceed number of Siemens specified hot and cold starts per hour.
Will cause overheating.
Allow time between starts to permit stator windings and rotor cage to cool.
NOTE
If motor has been out of service or in storage for more than 30 days, consult Siemens Storage Recommendations ANIM-03114, Preparation for
Service
After installation is completed, but before motor is put in regular service, make an initial start as follows:
1. Check that motor, starting, and control device connections agree with wiring diagrams.
2. Check that voltage, phase, and frequency of line circuit (power supply) agree with motor nameplate.
3. Check motor service record and tags accompanying motor. Be certain bearings have been properly lubricated and oil wells are filled. See motor outline drawing to determine proper oil level.
4. If possible, remove external load (disconnect drive) and turn shaft by hand to assure free rotation. This may have been done during installation procedure; if so, and conditions have not changed, this check may not be necessary.
5. If drive is disconnected, run motor at no load long enough to be certain that no unusual condition exists. Listen and monitor for excessive noise, vibration, clicking or pounding and that oil rings are turning if so equipped. If present, stop motor immediately. Investigate the cause and correct before putting motor in service.
6. If drive cannot be disconnected, interrupt the starting cycle after motor has accelerated to low speed. Carefully observe for unusual conditions as motor coasts to a stop. Repeat several times if necessary. Refer to motor’s Starting Duty nameplate (if so equipped) or Motor Data Sheet for recommended number of starts and cooling period between starts..
7. When checks are satisfactory, operate at lowest load possible and look for any unusual condition. Increase load slowly to maximum, checking unit for satisfactory operation.

Oil Circulating Systems

For motors with oil circulating systems, proceed as
follows before startup;
1. Fill motor reservoirs to normal level (see motor outline drawing).
2. Follow instructions provided by the oil circulating system supplier.
3. Put oil circulating system into operation before starting motor.

Normal Operation

Start the motor in accordance with standard instructions for the starting equipment used. Sometimes the load should be reduced to the minimum, particularly for reduced voltage starting, and/or high inertia connected loads.

Voltage/Frequency Variation

Motors will operate successfully under the following conditions of voltage and frequency variation, but not necessarily in accordance with the standards established for operating under rated conditions:
1. If the variation in voltage does not exceed 10% above or below rated voltage, with all phases balanced. Voltage unbalance should not exceed 1%.
2. If the variation in frequency does not exceed 5% above or below rated frequency.
3. If the sum of the voltage and frequency variations does not exceed 10% above or below rated values provided the frequency variation does not exceed 5%.
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Operation

Trouble Shooting

Between regular maintenance inspections, be alert for signs of motor trouble. Common symptoms are listed in the following table. Correct any trouble immediately and AVOID COSTLY REPAIR AND SHUT DOWN.
Hazardous voltage.
Will cause death, serious injury, electrocution or property damage.
Disconnect all power before working on this equipment.
TROUBLE POSSIBLE CAUSES CORRECTION
Motor will not start.
Excessive hum.
Regular clicking. Foreign matter in air gap. Remove foreign matter.
Rapid knocking. Bad anti-friction bearing or dirt in lubricant. Replace bearing, clean grease cavities and
Vibration.
Usually line trouble. Single phasing at starter.
Under Voltage. Check voltage at motor terminals. Compare to
Excessive Load. Disconnect motor from load to see if it starts
High Voltage. Check input voltage. Check for proper
Unbalanced rotor. Balance rotor.
Excessive wear of sleeve bearings. Replace bearings. Check to determine cause
Misalignment in coupling or feet. Realign motor and driven equipment.
Check power source. DO NOT check with motor energized! Check overloads, controls and fuses. Check voltage and compare with nameplate rating.
nameplate.
without load. Reduce load or replace motor with unit of greater capacity.
connections.
of wear and replace as necessary. Check alignment.
renew lubricant.
DANGER
Vibration following motor repair.
Motor overheating. (Check with thermocouple or by resistance method, do not depend on touch).
Accumulation of dirt on fan. Clean motor.
Vibration in driven machine. Run motor disconnected from driven load and
check for vibration. Eliminate source in driven equipment.
System natural frequency (resonance). Alter rigidity of base structure.
Rotor out of balance; balance weights of fans shifted on rotor.
Overload. Measure load and compare with nameplate
Single phase. Check current, all phases.
Dirt in motor. Check flow of air.
Unbalanced voltage. Check voltage, all phases.
Rotor rubbing on stator. Check air gap. Repair motor as necessary.
Balance rotor.
rating. Check for excessive friction in motor or complete drive. Reduce load or replace motor with unit of greater capacity.
Check filters, if so equipped. Clean motor.
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