DC Motors, Installation, Operation and Maintenance Manual
Contents
1. Shaft Extension and Method Of Drive V belts should be within the limits of NEMA Standard MG1 14 67 a Frames DC180ATZ C180ATZ DC210ATZ are supplied with the same size shaft for either coupled or belted drives Table C Multipliers for Drives other than V belt Drive Multiplier Flat Belt See Note 1 1 33 Timing Belt See Note 2 0 9 Chain Sprocket 0 7 Spur Gear 0 75 Helical Gear 0 85 1 The above multiplier is intended for use with conventional single ply flat belts When other than single ply flat belts are used the use of a larger multiplier is recommended 2 Itis often necessary to install belts with a snug fit However tension should be no more than necessary to avoid belt slap or tooth jumping Shaft Loads Axial and Radial DC motors are suitable for limited shaft load as shown in Tables D and E Recommended maximum thrust loads depend on the mounting position either horizontal or vertical For load recommendations in excess of those shown contact your local Sales Office the accurate calculation of the radial load for the application Radial loads for gears sprockets and flywheel are usually accurately determined but the radial loads due to V belt drives are subject to miscalculations because they do not include all of the pre tension load belt tightening The calculations of the radial load for a V belt drive must include the pre tension for transmitting the horsepower pre tension for centrifugal for2. temperature must not exceed the maximum ambient temperature indicated on the motor nameplate standard 40 degrees C 104 degrees F Cooling air temperature must not be lower than 0 degrees C to provide base speed and regulation within NEMA limits Use of outside air below 0 degrees C may cause excessive brush and commutator wear due to the low humidity Cooling air absolute humidity must be at least 2 grains per cu ft Important Motors located in damp moist environment must have space heater or fields energized at 50 voltage to protect against condensation when motor is not operating Separately ventilated motors must have the following volume of air to adequately cool the motor unless the motor nameplate specifies a different value Base Speed Air Volume _ Static Pressure Frame RPM CFM Inches of Water DC180ATZ 2500 152 2 0 C180ATZ and 1750 and lower 105 0 95 DC210ATZ Power Supply Check the motor nameplate to be sure the voltage and type of power rating is the same as that of the power source A code stamped on the nameplate identifies the type of power supply that must be used to supply armature power to the motor in order to obtain the rated nameplate output Since the code letter has been selected in alphabetic order of increasing magnitude of ripple current a motor may be operated on a power supply having a letter designation prior in the alphabet to the letter stamped on the nameplate with no loss in nameplate rati
3. B CONTROLMAITCHED Variable Speed Solutions Installation Operation and Maintenance Manual DC Motors e Frames DC180ATZ C180ATZ and DC210ATZ Rockwell Automation 2 DC Motors General Description The products described in this publication are designed specifically for use on rectified power The basic design includes Class F Insulation 1 0 Service Factor 40 degree C 104 degree F ambient continuous duty with drip proof guarded and force ventilated enclosure with horsepower speed ratings overload and voltage in accordance with NEMA Standards A wide variety of modifications enclosures and accessories is available the construction and operation of this equipment and the hazards involved should install adjust operate and or service this motor Read and understand this manual in its entirety before proceeding Failure to observe this precaution could result in personal injury or loss of life ATTENTION Only qualified electrical personnel familiar with Table of Contents General Description 24442hy sce seuranaan 2 Receiving and Handling cc0 ieceehet ene enbeieer ener es 2 stalai eee A E E E E S 3 Motor Application Data 32 2220542 deds ebGenedewhbedeonns 8 Oper t essesi denea sate ried eeteawas a a e a E 12 Maintenances 405 35 4 hoe hoe ea a ee ceed Saeed 15 Disassembly amp Reassembly Instructions pal Acceptance Thoroughly inspect this equipment before accepti
4. Relative Polarity of DC Motor Fields Motor speed is unstable if speed increases due to an increase in load current As a result of instability motor speed may hunt or overspeed These are unsatisfactory possibly dangerous drive conditions One of the possible causes of unstable performance of shunt wound DC motors is incorrect series field polarity relative to the shunt field due to improper connection Relative polarity of the shunt and series fields can be checked as follows 1 Connect a low scale 3 volt DC voltmeter across the shunt field terminals F1 F2 with F1 connected to the positive terminal of the meter At least one of the shunt field leads must be disconnected from the controller 2 Use two flashlight batteries as a source of low voltage 3 volts Hold or connect the negative to contact the S 2 series field terminal Hold one end of a wire conductor to the positive center terminal so that the other end of the wire can be used to make and break contact with the S I series field terminal 3 Watch the deflection of the voltmeter needle when contact is made with S I and when contact is broken Maintenance DC Motors 15 4 When contact is made the needle will first deflect in either the up scale or down scale direction and then return to zero Deflection will be in the opposite direction when contact is broken 5 Relative polarities of the shunt and series fields are correct ampere turns are cumulative i
5. al 3 Commutator dirty 4 Incorrect spring tension 5 Machine overload or rapid load change such as plugging 6 Bar marking at pole pitching 1 Two bars marking 180 degrees C 356 degrees F 1 Shorted commutator bars or coils spacing apart on 4 pole machine at start 2 Open armature or field circuit 2 Three bars marking 120 degrees C 248 degrees F 3 Unequal air gap apart on 6 pole machine at start 4 Cyclic disturbance either electrical or 3 As pitch bar marking progresses it will eventually mechanical show at all bars on the machine 4 Associated sparking and eventual flashover 7 Bar marking at slot pitch Sparking and marking of one or more bars at equal 1 Unequal compensation of armature coils The spacing spacing around commutator according to bar per slot ratio energy unbalance is reflected into the last coil in with eventual flashover the slot to undergo commutation and will result in a spark at the brush 8 Rapid commutator or brush Bright commutator surface 1 Abrasive material under brush wear 2 Too abrasive a brush 3 Low average brush current density due to light machine loading 4 Contaminated atmosphere Oa Humidity too low Incorrect brush tension Disassembly amp Reassembly Instructions DC Motors 21 Windings For long life keep windings clean and dry Dirt or dust can be removed by wiping them with a clean cloth by blowing with clean dry low pressure air or by vacuum cleane
6. all bearings at the drive end are for coupled duty only Deriving Motor Constants Various motor constants are required to set control functions for stabilized operation of motor and controls The following information will make it possible to derive approximate motor constants from the nameplate data Required Nameplate Data Frame HP RPM Volts Va Amps Ia From Table F the following factors are available based on frame size Ra La WK Te This will provide approximate results with a 25 margin of error The following data can be derived La La x Va rpm Arm Circ Ind millihenries Ra Ra x Va rpm Arm Circ Resistance Te Te te La Ra x 10 Elec Time Constant J SEC WK x rpm 1 62 x 10 x hp where WK is in terms of lb ft J SEC WK x rpm 0 0922 x 10 x kw where WK is in terms of kg m R la x Ra Va laRa Table F Resistance amp Inductance Factors WK Frame lb ft kg m2 Ra C1811ATZ 0 683 0 029 566 616 0 011 C1812ATZ 0 787 0 033 40 5 500 10 012 12 DC Motors Operation Balance Motors are dynamically balanced to commercial limits unless ordered differently Balance is done with a full length 1 2 height shaft key A full shaft key is shipped with the motor Sheave or coupling should be balanced with a 1 2 height shaft key Table G Standard Dynamic Balance Limits Highest Rated Speed Maximum Amplitu
7. ard bearing cavity 60 to 90 full of grease 5 If possible rotate shaft of assembled machine at least three revolutions by hand to distribute grease within bearings before starting motor Bearings These motors are designed to provide a mounting for anti friction bearings to give e Maximum protection to windings and interior of machine by preventing grease leakage from bearing housing e Maximum protection to bearings against excess lubricant insufficient lubricant dirt and moisture Various types of anti friction bearings are used in the wide range of frames as needed to meet specific load speed and service requirements Most commonly used bearings are e Single row open ball bearings for coupled and belted duty for frames C180ATZ Frames DC180ATZ and DC210ATZ have a single shielded bearing on the commutator end Frequent bearing checks are recommended If temperatures become excessive investigate immediately for the cause Total bearing temperatures should not exceed 90 degrees C 194 degrees F Causes for high bearing temperature are Contaminated grease Insufficient grease or excessive amount Incorrect grease Excessive load or thrust due to misalignment or motor overload Loose bearings Bearing failure Excessive ambient temperature DC Motors 19 Replacement bearings should be ordered from Allen Bradley in order to obtain the same carefully selected bearing as the original Bearings should never be ex
8. cation Interval Months Maximum Normal Standard Severe Extreme Operating Speed RPM Frame Service Service Service 3450 and higher C180ATZ 9 4 1 2400 3449 C180ATZ 24 9 3 1700 2399 C180ATZ 36 12 3 800 1699 C180ATZ 36 24 8 500 799 C180ATZ 48 36 12 499 and lower C180ATZ 48 36 12 1 Maximum speed occupying more than 30 of operating time 2 For Tandem drives increase frequency of lubrication by multiplying values by 0 8 Lubrication Frames C180ATZ These motors are designed to route new grease directly into the bearing The relubrication periods shown in Table J are offered as a guide for varying service conditions speeds bearing types and operating hours Important Certain special motors may have a lubrication instruction plate permanently attached These specific lubricating instruction must be followed Lubrication Procedure rotating parts or electrical shock relubrication should only be performed while the motor is stationary and disconnected from the power source ATTENTION To guard against personal injury or death from 1 Relubrication with the shaft stationary and a warm motor is recommended 2 Locate the grease inlet at the top of the bearing hub clean the area and replace the 1 8 inch pipe plug with a grease fitting if the motor is not equipped with a grease fitting 3 When provided remove grease drain plug located opposite the grease inlet The following motors do not have a grea
9. ce on the belts pre tension for high start torques rapid acceleration or deceleration pre tension for drives with short arc of contact between the V belt and sheave and low coefficient of friction between belt and sheave caused by moisture oil or dust Failure to observe these precautions could result in damage to or destruction of the equipment ATTENTION The use of these radial load capacities requires Table D Axial Thrust Capacity Horizontal Mounting Vertical Mounting Frame Units 2500 RPM 1750 1150 850 2500 1750 1150 850 RPM DC180ATZ amp Ibs 176 207 251 286 190445 217445 265 45 295 45 DC210ATZ kg lao 94 i14 130 86 20 l99 20 12020 134 20 C180ATZ Ibs 295 345 417 477 370445 357445 430 45 492 50 kg 134 156 189 216 1394 20 162 20 195 20 223 20 1 Thrust capacity for vertical mounting includes a constant whose value is plus or minus depending on the direction of the thrust load The constant is plus for thrust loads acting upward against the force of gravity and minus for loads acting downward with gravity DC Motors 11 Table E Radial Load Capacity Capacity at End of Shaft in kg Ibs Frame 2500 RPM 1750 RPM 1150 RPM 850 RPM DC210ATZ amp 140 6 310 156 5 345 179 2 395 200 0 440 DC180ATZ C180ATZ _ 226 8 500 256 3 565 283 5 625 283 5 625 1 Data for motors with roller bearings at the drive end back end Motors with b
10. d use a D Flange reach temperatures which can cause discomfort or injury to personnel coming into contact with hot surfaces The user must apply appropriate guards and or shields to protect against accidental contact with motor surface Failure to observe this precaution may result in personal injury ATTENTION Surface temperature of the motor enclosure may 8 DC Motors Motor Application Data Direction of Rotation Unless otherwise ordered brush rigging is assembled for NEMA standard direction of rotation counterclockwise for motors and clockwise for generators facing the commutator end These motors will operate in either direction of rotation without changing the angle of the brush holders for normal field weakened speed ranges Extended field weakened speed range motors should have the direction of rotation specified Drive DCI180ATZ C180ATZ amp DC210ATZ frame motors are supplied with a shaft suitable for a belt or coupled drive Proper alignment is a key step for long life of bearings shafts and belts and minimum downtime Misalignment can cause excessive vibration and damaging forces on shaft and bearings For direct coupled drives flexible couplings facilitate alignment For belt drives the driving and driven tension must be adjusted as required for proper operation The belt sheaves should be placed as close as possible to the motor bracket ATTENTION To guard against personal injury and or machine damage caus
11. de RPM Inches 3 000 4 000 0 0010 1 500 2 999 0 0015 1 000 1 499 0 0020 Up to 999 0 0025 Series Wound Motors Important Series wound motors must be solidly connected to the driven machine and never operated without load to avoid possible destructive high speeds Motor Start up damage observe the following precautions before initial start up ATTENTION To guard against personal injury and or machine e Remove all unused shaft keys and loose rotating parts to prevent them from flying off Replace covers and protective devices e Verify that all separately excited fields are excited at their rated voltage and that relative polarities of all fields are correct See Checking Relative Polarity of DC Motor Fields on page 14 e When the motor is supplied as part of drive system refer to the Drive User Manual for operating instructions Tachometer feedback must be properly connected for closed loop operation Reverse polarities or broken connections can cause dangerous overspeeds Maximum safe mechanical operating speeds are shown in Table B on page 9 Motor control circuitry must prevent motor speeds from exceeding the stated values DC Motors 13 In addition to observing the above precaution all precautions Attentions mentioned in this document should be observed The following items must be checked before starting and during operation e The armature should rotate freely and be clear of a
12. dquarters Americas Rockwell Automation 1201 South Second Street Milwaukee WI 53204 2496 USA Tel 1 414 382 2000 Fax 1 414 382 4444 Europe Middle East Africa Rockwell Automation Vorstlaan Boulevard du Souverain 36 1170 Brussels Belgium Tel 32 2 663 0600 Fax 32 2 663 0640 Asia Pacific Rockwell Automation Level 14 Core F Cyberport 3 100 Cyberport Road Hong Kong Tel 852 2887 4788 Fax 852 2508 1846 Publication 1325L UM001B EN P August 2001 Supersedes 1325L UM001A EN P dated May 2001 Copyright 2001 Rockwell Automation All rights reserved Printed in USA
13. earing has cooled down for about 1 minute add 1 2 cu in of fresh grease into back of bearing When the motor has been assembled grease per instructions found on page 15 DC Motors 23 Brush Rigging and Brush Holders The brush holders in all motors are often constant pressure design and do not require nor are capable of adjustment over the life of the brushes DC180ATZ amp DC210ATZ Conduit box is attached to the commutator end top hand hole cover and cannot be located on the side C180ATZ Conduit box is located on the commutator end bracket Parts Identification C180AT DC180ATZ amp DC210ATZ aD 2 02 AD 014 GDIDA LOAD NS 2 we ies a es Ke CEE wr a p A AZA DS 1 E Number Description Number Description 1 Grease Plug C180 only FE 12 Inner Coil 2 Grease Plug C180 only BE 13 Armature Core 3 Ball Bearing FE 14 Frame 4 Ball Bearing BE 15 Armature Coil 5 Rocker 16 Inner Fan 6 Bracket FE 17 Key 7 Bracket BE 18 Shaft 8 Brush 19 Conduit Box 9 Brush Holder 20 Bearing Cap BE 10 Commutator 21 Bearing Cap C180 only FE Cap not shown 11 Field Coil Online Documentation The latest motor information can be obtained from the Allen Bradley Drives amp Motors home page on the World Wide Web at http Awww controlmatched com www rockwellautomation com Power Control and Information Solutions Hea
14. ed by incorrect motor rotation verify direction of A motor rotation before coupling motor to load ATTENTION Ensure that all guards are properly installed to guard against personal injury caused by contact with rotating parts Shipping Blocks Motors supplied with roller bearings at the drive end are shipped with wooden blocking to prevent axial movement of the shaft during shipment Remove the blocking and bolts securing it and discard Make sure motor shafts turn freely If motor is to be reshipped blocking of bearing is required Maximum Safe Speed responsible for assuring that all drive train mechanisms the driven machine and process material are capable of safe operation at the maximum speed at which the machine will operate Failure to observe these precautions could result in personal injury ATTENTION The machinery builder and or user are DC Motors 9 The speeds given in Table B are the maximum mechanically safe operating speeds for frames with standard construction These speeds must not be exceeded under any condition Motor control must hold the maximum speed under any load condition including no load within the maximum safe speed Drive systems whose design characteristics inherently prevent the DC motor from exceeding the motor maximum safe operating speed must prevent the motor from exceeding the maximum safe speed if a single component failure should occur Table B Maximum Safe Speed Frame Diame
15. f the voltmeter needle deflects up scale when contact is made and down scale when contact is broken 6 Relative polarities of the shunt and series fields are incorrect ampere turns are differential if the voltmeter needle deflects down scale when contact is made and up scale when contact is broken The motor connections must be changed so that relative polarity is correct Relative polarity can be incorrect because of an error in the connections to the control or because the series fields leads are improperly marked In any case the motor connections must be changed so that relative polarity is correct If only one series field terminal is available at the controller use it and the available armature terminal for the test For example use S 2 and A I if S 1 and A 2 arc connected together at the motor and not brought to the controller potential even when it is not rotating Before performing any maintenance which could result in contacting any internal part be sure to disconnect all power from the motor Failure to observe this precaution could result in severe personal injury or death ATTENTION Internal parts of this motor may be at line Inspections Regular inspection at intervals dependent upon service conditions is the best insurance against costly maintenance and breakdown Experience is the best guide Record inspection results and maintenance action required or performed Cleanliness Keep the interior parts of mach
16. ines clean and dry Remove dust dirt corrosion grease oil and moisture If used ventilating air filters must be kept clean or replaced to assure full volume of cooling air Lubrication Frames DC180ATZ amp DC210ATZ DC180ATZ frame has oversize grease reservoirs to provide lifetime operation in normal industrial applications Where severe duty conditions require regreasing the following procedures should be followed 16 DC Motors Drive End Bearing Bearing fits in machined cavity in bracket with inner cap To regrease bearing remove bracket four nuts hold bracket to frame and inner cap two bolts Clean old grease from bearing and cavity and repack with Chevron SRI 2 or equivalent grease Commutator End Bearing Bearing has single shield and single seal with seal on side facing commutator To regrease bearing snap out brushes and remove bracket four nuts hold bracket to frame Clean old grease from around bearing and cavity and repack around bearing and Chevron SRI 2 or equivalent grease Amount of grease to be added to motors is shown in Table H See Table J for relubrication interval Use Chevron SRI 2 or equivalent grease unless motor nameplate specifies special grease Recommended Lubricant For motors operating in ambient temperatures shown below use the following lubricants or their equivalent Ball Bearing Motors Operating Temperature Chevron Oil SRI No 2 25 to 50 degrees C 15 to 120 degree
17. nd Guide for Selection Installation and Use Of Electric Motors And Generators published by the National Electrical Manufacturers Association NEMA publication MG 2 1983 ANSI C51 5 It is recommended that this publication be referred to whenever you select or install any motor The application of motors and other electrical equipment in hazardous locations is restricted by the National Electric Code Users must observe these regulations and consult with local code inspection and enforcement agencies to insure compliance 4 DC Motors Location Locate the machine where the ambient temperature is not over 40 degrees C 104 degrees F and where clean air has free access to ventilating intake and outlet openings Except for machines with a suitable protective enclosure the location should be clean and dry Important Sufficient clearance must be provided on all inlet and outlet openings to provide for unrestricted flow of air Separately ventilated motors with exhaust to ambient pipe in only must have at least 152 4 mm 6 in of clearance between the opening and adjacent walls or floor Air Supply Cooling air through a self ventilated or forced ventilated motor must be clean and have relative humidity between 30 and 100 with no free water in the air Use of damp cool outside air with high humidity and free water may cause the motor to flash over Use of excessively dry air may cause excessive brush and commutator wear Cooling air
18. ng DC Motors 5 For example a motor designed for a D type of power supply may be used on a C power supply having the same voltage rating The types of power supplies are defined as follows Managindianm CC P el Description Code DC generator battery or twelve pulse cycle 6 phase full control Six pulse cycle 3 phase full control 230 or 460 volt 60 Hz input to rectifier Three pulse cycle 3 phase semi bridge half contro 230 or 460 volt 60 Hz input to rectifier Three pulse cycle 3 phase half wave single way 460 volt 60 Hz input to rectifier Two pulse cycle 1 phase full wave bridge circuit with 2 controlled rectifiers and 2 uncontrolled rectifiers with free wheeling rectifier 230 volt 60 Hz input Alm OOS 1 When the armature power supply cannot be designated by a single letter code A K etc the power supply shall be identified by the following code stamped on the motor nameplate M N F V H L where M Total pulses per cycle N Total controlled pulses per cycle F Free wheeling if used V Nominal line to line a c voltage to rectifier H Line frequency Hz L Value of series inductance in millihenries to be added externally to the motor armature circuit Examples A 6 3 F 380 50 12 defines a power supply having 6 total pulses per cycle 3 controlled pulses per cycle S 3 with free wheeling 380 volts 50 Hz AC input to bridge and a 12 millihenry choke to be added externally
19. ng shipment from the transportation company If any of the goods called for in the bill of lading or express receipt are damaged or the quantity is short do not accept them until the freight or express agent makes an appropriate notation on your freight bill or express receipt If any concealed loss or damage is discovered later notify your freight or express agent at once and request him to make an inspection We are willing to assist you in collecting claims for loss or damage in shipment however this willingness on our part does not remove the transportation company s responsibility in reimbursing you for collection of claims or replacement of material Claims for loss or damage in shipment must not be deducted from the invoice nor should payment of the invoice be withheld awaiting adjustment of such claims as the carrier guarantees safe delivery If considerable damage has been incurred and the situation is urgent contact the nearest Allen Bradley Sales Office for assistance Please keep a written record of all such communications Installation DC Motors 3 Handling lifting the motor only with the standard accessories such as tachometer brakes etc mounted by Allen Bradley The lifting means on the motor must not be used to lift the unit plus additional equipment The lifting means on the motor cannot be used to lift assemblies or equipment mounted on a common base Failure to observe this precaution could result in personal inju
20. ny obstructions e The brushes should move easily in their holders and should make proper contact on the commutator e The interior of the motor should be clean and dry e Connections must be tight e The driven machine should be unloaded if possible When starting small sparks may appear on the commutator due to particles of dirt Other than this there should be little if any sparking at the brushes Important Machines designed for cooling by a separate source of forced ventilation must not be operated without the air supply Be sure blower is running in proper direction While operating the motor observe the performance It should run smoothly with little noise The bearings should not overheat and should reach a leveling off temperature Any undue noise overheating sparking or erratic performance should be investigated and necessary corrective action taken immediately to prevent serious damage Before attempting any repairs please contact your Allen Bradley Sales Office All motors are lubricated before shipment and will operate for a long period before regreasing is required The period will vary depending on environmental and service conditions Refer to Maintenance on page 15 reach temperatures which can cause discomfort or injury to personnel coming into contact with hot surfaces The user must apply appropriate guards and or shields to protect against accidental contact Failure to observe this precaution may re
21. o be resurfaced Roughness can be easily detected with the machine running by resting a pencil like rod of insulating material dry wood on one of the brushes In mild cases a commutator dressing stone can be used Very rough or out of round commutators require turning in a lathe In every case maintain concentricity and remove the minimum material required for proper cleanup Undercut the mica approximately 1 16 and polish Adjust brush holders for approximately 1 8 clearance to commutator The finished diameter and the minimum diameter of the commutator for the various frames sizes are as follows New Diameter Minimum Diameter Frame Inches Millimeters Inches Millimeters DC180ATZ amp 3 01 76 5 2 62 66 5 DC210ATZ C180ATZ 4 12 104 8 3 66 93 0 The commutator should be replaced if the final diameter would have to be turned down to a value less than minimum limits 20 DC Motors Commutation Intermittent sparking due to overloads or slight visible sparking does not necessarily indicate poor commutation Poor commutation exists when there is excessive sparking requiring abnormal maintenance Every case of excessive sparking should be investigated to determine the cause and correct it The chart in Table K may help in analyzing commutation problems DC motors and generators are brushed for full load current If unit or units are consistently operated at less than 1 2 rated load a condition kno
22. onnected to stop the drive within 30 seconds upon tripping Failure to connect the thermostat leads will void the motor warranty the rating of the thermostat contact is Maximum Voltage 250V 60 Hz Rated Current 6 3 amps Maximum Breaking Current 20 amps Motors with an overspeed switch must have the overspeed switch terminals properly connected in the control circuit to remove armature power when the switch reaches the set speed The user is responsible for assuring that the grounding method is in accordance with the National Electric Code and the applicable local codes The ground connection should be a solid and permanent metallic connection between the ground point the motor terminal housing and the motor frame On two pole units DC180ATZ C180ATZ amp DC210ATZ the ground connection is a tapped hole in the end bracket adjacent to the conduit box DC Motors 7 Mounting Motors must be mounted on a rigid solid base or foundation Poor base construction may cause resonances in the motor base assembly which can result in bearing failure and other motor damage All hold down bolts must be the correct grade for the type of mounting and must be torqued to their recommended value Table A Recommended Torque Hole Diameter Bolt Size and SAE Grade Dry Components Not Lubricated Frame mm in Thread N m Ib ft C180ATZ 181 18 Belted Drive Motor slide bases or rails when used must be securely anchored to
23. posed by disassembly of the motor unless absolutely necessary for inspection or replacement of the bearing or maintenance in other parts of the machine Protect good bearings from dirt and contamination at all times Most bearing failures are caused by dirt The open ball bearings for motor frames C180ATZ are the same regardless of whether application is coupled or belted Brushes Brush pressure is correctly established at the factory and maintained at the correct value throughout the life of the brush by means of a constant pressure design Brushes and brush holders should be clean so that the brushes are free to move in the holders Replace brushes with new brushes of the same grade before wear permits the rivet or tamped pigtail to score the commutator It is best to change out complete set Fit the face of new brushes to the contour of the commutator with sandpaper only no emery abrasive Keep brush lead pigtail connections tight Replacement brushes should have sleeved pigtails that all power to the motor has been removed and the motor shaft is stationary Brushes must not be touched or replaced while motor is energized or rotating ATTENTION To guard against personal injury or death ensure Commutator A commutator in good condition is clean and smooth with a medium polish and a light brown color Keep clean by occasionally wiping with a canvas pad Use no lubricant or emery abrasive If a commutator becomes rough it needs t
24. possible damage or harm to either machine and or maintenance personnel 22 DC Motors Air Gap And Shimming Frame C180ATZ Main Pole Steel or brass shims when used are placed between pole and frame If for any reason the shims are removed they must be replaced under the same poles Main pole bolts are steel SAE Grade 5 120 000 psi Axial Float Frames C180ATZ have wavy spring washers between B E bracket and bearing Axial float should be within the limits listed on the chart below Axial Float Frame Maximum Minimum All 1 22 mm 0 048 in 10 20 mm 0 08 in Anti friction Bearing Assemblies The bearings are positioned and secured by various means depending on size and application requirements Open type ball bearings are used for direct coupled and belt drive applications Below are standard construction details for the various frames DC180ATZ amp DC210ATAZ Drive end bearing fits in a machined cavity in the bracket with inner cap Commutator end bearing has single seal on side facing commutator C180ATZ Bearings fit in a machined cavity in the end brackets Inner caps are used Bearing Replacement Remove bearing by means of bearing puller Clean bearing housing and bearing seat prior to assembly of bearing Place new bearing in a bake oven for one hour at 121 degrees C 250 degrees F Place bearing onto shaft and push home to bearing shoulder Hold it in place for a minimum of 30 seconds After b
25. provided with thermal protection typically thermostats it is important to properly connect and apply the devices This will ensure that the motor is properly protected from being operated if thermal limits are reached and or exceeded The control system must be configured to reduce the motor load and or shut down the motor control system to allow the motor to cool to a level within acceptable operating ranges If the motor is operated with the thermal protective devices tripped indicating an over temperature condition the motor insulation could be damaged and complete failure of the motor insulation is possible In the event of motor failure due to an over temperature condition Rockwell Automation requires that motor thermal protective devices when supplied be adequately monitored and incorporated into the motor control system to maintain warranty Failure on the part of the individual installing this equipment to take these steps will result in the factory warranty being voided Motors may have one or more thermostats leads marked P1 P2 etc designed to trip before the frame reaches the maximum allowable temperature for specific class and group The normally closed contacts of the thermostat must be connected in that motor control circuit so that power to the motor armature and field is removed immediately when the thermostat trips An explosion proof tachometer mounted on the motor will also have an internal thermostat which must be c
26. r Oil or grease can be removed with a cloth moistened with mineral solvent Be sure not to get any solvent on the commutator and observe all product warnings Filters Cleaning When supplied filters on motors must be kept clean to assure proper air flow and cooling of the motor The following procedure should be used to clean these filters For light accumulations of dust use compressed air to clean For moderate accumulations water may be used For heavy accumulations of dirt and grease clean the filter using water and detergent Always completely dry filter after cleaning with water After heavy cleaning spray with a very light coat of protective oil to protect against possible loss of plating Important Do Not use flammable solvents to clean filters Important Standard washable filters may not be suitable for motors operating in atmospheres with heavy concentrations of oil mist Oil mist may be drawn into the motor and cause damage to the commutator and windings Contact Allen Bradley for motors operating in heavy oil mist atmospheres Brakes Motor mounted brake when supplied must be adjusted and maintained in accordance with the instructions for the specific brake Refer to separate instructions supplied with the motor The motor design incorporates many new techniques which are described in this section It is recommended that these differences be understood thoroughly before any disassembly work is done to avoid
27. ry ATTENTION Eyebolt s or lifting lug s are intended for In all cases care should be taken to assure lifting in the direction intended in the design of the lifting means Lift using all lugs provided Likewise precautions should be taken to prevent hazardous overloads due to deceleration acceleration or shock forces Angle of lift with rope or chain must be greater than 45 degrees from horizontal For unusual conditions such as side wall and ceiling mounting of horizontal motors or installation of vertical motors shipped in a horizontal position special precautions must be taken It is recommended that an experienced rigger be employed Storage Motors must be stored in a clean dry area protected from extremes of temperature moisture shock and vibration Storage temperatures of 10 to 49 degrees C 50 to 120 degrees F with a maximum relative humidity of 60 must be observed In addition motors subjected to extended storage must be handled and treated per the requirements specified in publication Motors 5 0 This publication is available from your Allen Bradley Sales Office or online at http Avww controlmatched com DC motors have characteristics which can cause serious or fatal injury unless they are selected installed maintained and operated by qualified personnel familiar with special requirements of DC machines Allen Bradley DC motors are designed and built in accordance with Safety Standard for Construction a
28. s F Exxon Unirex N2 Shell Oil Co Dolium R Texaco Inc Premium RB Minimum Starting Temperature Shell Oil Co Aeroshell 7 60 degrees C 76 degrees F Table H Coupled Belted or Tandem Duty Grease Amounts Volume Weight Frame Cubic Inches Cubic Centimeters Ounces Grams C180ATZ moo o e o o Using the table below determine service condition on the basis of the most severe operating parameter i e temperature bearing load atmosphere or operating hours per day Table Service Condition Service Operating Condition Ambient Temperature Bearing Load Atmosphere Hours Day Standard 18 to 40 degrees C Steady Clean 8 0 to 104 degrees F Severe 30 to 50 degrees C Medium Shock Vibration Medium Dirt 8 to 24 22 to 122 degrees F less than 0 2 in sec Abrasives Corrosion Extreme 54 to 65 degrees C Heavy Shock Vibration Heavy Dirt 8 to 24 65 to 149 degrees F more than 0 44 in sec Abrasives Corrosion 1 Motors must be specially designed for operation in ambient outside the range of 30 to 40 degrees C 22 to 104 degrees F Special grease is required 2 Extreme service conditions are rare in actual practice Corresponding lubrication cycles should therefore be applied with caution It is also advisable to check with Allen Bradley for related special instructions DC Motors 17 Table J Relubrication Periods Frames C180ATZ Relubri
29. se drain plug but have a grease relief around the grease inlet pipe Frames C180ATZ on commutator end opposite drive end All C Face and D Flange frames on drive end 4 Using a manual grease gun pump in the recommended grease in the amount shown in Table H This amount of grease will provide an ample supply of lubricant between lubrication periods as determined from Table J for the service condition listed in Table I An excessive amount of grease will damage the motor Use Chevron SRI 2 grease or equivalent unless motor nameplate specifies special grease Use only clean fresh grease from clean containers and handle carefully to keep it clean 18 DC Motors In general mixing of greases is not recommended If an incompatible grease is used the lube system must be repacked completely with the new grease 5 Wipe away any excess grease at the grease drain or relief and replace drain plugs Repacking Bearings or Greasing New Bearings When existing bearings have been completely cleaned of old grease or when bearings are replaced use this procedure for packing the bearing 1 Apply one bead of grease all around inboard side of bearing between bearing and inner cap making sure that grease adheres to balls or rollers 2 Apply one bead of grease all around outboard side of bearing making sure grease adheres to balls or rollers 3 Completely fill grease inlet and outlet passage holes with grease A Fill outbo
30. sult in personal injury ATTENTION Surface temperature of the motor enclosure may 14 DC Motors DC Motor Field Heating inadequate ventilation assure that motors designed for forced ventilation as standard 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 The motor insulation life can be significantly reduced if the above precaution is not followed ATTENTION To guard against motor damage caused by Standard continuous duty DPG TEFC and TENV stabilized shunt wound DC motors have continuous duty fields capable of continuous excitation at standstill armature circuit not energized under normal industrial conditions Important Motors designed for forced ventilation or with a dual cooled heat exchanger as standard 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 50 rated by means of field economizing resistor and relay Standard continuous duty self ventilated motors are suitable for rated load at rated speed operation at field voltages up to 110 of rated value However insulation life will be reduced if operated below 60 of base speed for prolonged periods Checking
31. ter Maximum Safe Speed DC180ATZ 4500 RPM C180ATZ 5000 RPM DC210ATZ 4500 RPM With special construction maximum safe speed may differ from the above values In all cases maximum safe speed is indicated on the motor nameplate Important Normal operating speeds must be limited to those listed in order to meet nameplate rating and assure validity of warranty Application of Pulleys Sheaves Sprockets and Gears On Motor Shafts To avoid excessive bearing loads and shaft stresses belts should not be tightened more than necessary to transmit the rated torque The pre tensioning of the V belt drive should be based on the total tightening force required to transmit the horsepower divided by the number of belts This procedure avoids the excessive load caused by tightening individual belts to a prescribed level recommended by belt manufacturers Mounting In general the closer pulleys sheaves sprockets or gears are mounted to the bearing on the motor shaft the less will be the load on the bearing This will give greater assurance of trouble free service The center point of the belt or system of V belts must not be beyond the end of the motor shaft The inner edge of the sheave or pulley rim should not be closer to the bearing than the shoulder on the shaft but should be as close to this point as possible The outer edge of a chain sprocket or gear must not extend beyond the end of the standard motor shaft 10 DC Motors
32. the foundation with the proper bolts Important The motor shaft and load shaft must be parallel and the sheaves aligned Refer to Motor Application Data on page 8 Coupled Drives Important Flexible couplings must be used between the motor shaft and the load shaft Motor shaft and load shaft must be aligned to values recommended for the specific coupling before coupling is connected Important Motors will operate successfully mounted on the floor wall or ceiling and with the shaft at any angle from horizontal to vertical Special mountings duty or thrust demands may however require a different bearing system Drive end bracket and or outer caps can be rotated either 90 or 180 degrees to conveniently locate grease fittings or air outlet openings Handhole covers can be interchanged as necessary Important Vertical mount drip covers are required to provide protection to vertically mounted Drip Proof motors Stock motors and other motors designed for horizontal mounting can be adapted for vertical mounting by ordering vertical mount drip covers Self ventilated frames cannot be mounted vertical shaft up and retain the drip proof feature due to louvers on the drive end bracket Motor C Face is intended for mounting auxiliary equipment such as pumps gears etc When mounted horizontally these motors should be supported by the feet and not by the C Face Installations requiring a horizontally mounted motor without feet shoul
33. to the motor armature circuit B 3 3 480 defines a power supply having three total pulses per cycle three control pulses per cycle 480 volts line to line input to the rectifier 60 Hz power supply and no external inductance required in the armature circuit Note that since the power source is 60 Hz and no series inductance is required both quantities may be omitted from the code If one of the quantities is indicated both must be included to avoid confusion Conduit Box Conduit boxes can be rotated in 90 degree increments for lead outlet at top sides or bottom Conduit box locations can be changed from F1 to F2 or F2 to F1 by rotating the commutator end bracket 180 degrees and reconnecting the leads The conduit box location cannot be changed on DC180ATZ amp DC210ATZ frames Connections Important If motor has parallel leads all lugs with the same marking For example Al A1 must be connected together Figure 1 Basic DC Motor and Generator Connections Rotation Facing Commutator End Type CCW CW Motor 41 s2 Al s2 A2 Fi A2 F Si I F2 S1 F2 Generator A1 S2 A1 e 82 A20 FI A2 MFI ste wife ste w F2 If machine has no series field disregard S1 and S2 above For machines with special windings refer to motor or generator and controller diagrams 6 DC Motors Thermostat Thermal Protector Important Important Important Grounding When motors are
34. wn as threading will result Table K Commutation Problem Quick Check Symptom Identified By Possible Cause 1 Excessive sparking at motor Sparking 1 Dirty or corroded commutator due to dirt or generator commutator ambient contaminants oil or oil mist etc 2 Brushes incorrectly seated 3 High or feather edged mica 4 Faulty machine adjustment 5 Interpoles failed or improperly adjusted 6 Loss of brush spring tension 7 Brushes sticking in brush holder 8 Unit overload 9 Defective commutator or armature 10 Unequal spacing of holders around commutator 2 High commutator bars Generally associated with sparking and noisy operation of 1 Loose commutator produce a rough commutator the brushes on the commutator 3 Low commutator bars Generally associated with sparking and noisy operation of 1 Loose commutator produce rough commutator the brushes on the commutator 2 High mica 3 Open or high resistance connection at commutator 4 Streaking or threading of Rough commutator with associated sparking Fine lines in 1 Low average current density in brushes due to commutator surface brush track light machine loading 2 Contaminated atmosphere 3 Oil on commutator or oil mist in air 4 Humidity too low 5 Lack of film forming properties in brush 6 Brush too abrasive 5 Bar etching or burning Rough commutator with associated sparking and eventual 1 High mica flashover 2 Operation of machine with brushes off neutr
Download Pdf Manuals
Related Search