DC Motors, Installation, Operation and Maintenance
Contents
1. DC Motors 25 Total Service Programs Allen Bradley can provide a wide range of maintenance programs to help you reduce downtime improve productivity and increase profits Capabilities include Motor Start up Service Motor Electrical and Mechanical Preventive Maintenance Vibration Analysis Mobile Van Repair Service Balancing and Alignment Service Maintenance Service 24 Hour Technical Support Modernization Service For more information contact your local Allen Bradley Sales Office 26 DC Motors Notes Notes DC Motors 27 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 ab com drives motors www rockwellautomation com Power Control and Information Solutions Headquarters 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 UM002A EN P August 2001 Supersedes 1325L 5 0 dated March 1999 Copyright 2001 Rockwell Automation All rights reserved Printed in USA2. C4011ATZ lbs 1350 1630 2000 2250 1470 655 1820 655 2210 655 2475 65 kg 614 741 909 1023 668 298 827 298 1005 298 1125 29 MC4013ATZ Ibs 1310 1580 1975 2200 1460 825 1810 825 2200 825 2460 82 kg 595 718 898 1000 662 374 823 374 1000 374 1118 37 C440ATZ Ibs 1350 1650 2000 2250 1470 825 1820 825 2210 825 2475 825 kg 612 748 908 1021 714 374 828 374 986 374 1123 374 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 Table F Radial Load Capacity Capacity at End of Shaft in kg Ibs Frame 2500 RPM 1750 RPM 1150 RPM 850 RPM C210AT 488 1075 510 1125 510 1125 510 1125 C250ATZ 726 1600 794 1750 896 1975 941 2075 UC280ATZ 1225 2700 1225 2700 1225 2700 1225 2700 UC320ATZ 1452 3200 1452 3200 1452 3200 1452 3200 UC360ATZ 1814 4000 1814 4000 1814 4000 1814 4000 UC400ATZ 2722 6000 2722 6000 2722 6000 2722 6000 UC440ATZ Contact Allen Bradley for radial load applications 1 Data for motors with roller bearings at the drive end back end Motors with ball bearings at the drive end are for coupled duty only ATTENTION The use of these radial load capacities requires the accurate calculation of th
3. 50 degrees C 15 to 120 degrees F Texaco Inc Premium RB Table G Coupled Belted or Tandem Duty Grease Amounts Volume Weight Frame Cubic Inches Cubic Centimeters Ounces Grams C210ATZ C280ATZ 1 0 16 0 5 14 C320ATZ C400ATZ 2 0 32 1 0 28 C440ATZ 3 0 48 1 5 42 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 DC Motors 17 Table H 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 1 less than 0 2 in sec Abrasives Corrosion Extreme2 54 to 65 degrees C Heavy Shock Vibration Heavy Dirt 8 to 24 65 to 149 degrees F 1 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 Table Relubrication Periods Frames C210ATZ C440ATZ Relubricatio
4. Sparking and marking of one or more bars at equal spacing around commutator according to bar per slot ratio with eventual flashover Unequal compensation of armature coils The energy unbalance is reflected into the last coil in the slot to undergo commutation and will result in a spark at the brush 8 Rapid commutator or brush wear Bright commutator surface 1 Abrasive material under brush Too abrasive a brush Low average brush current density due to light machine loading Contaminated atmosphere Humidity too low Incorrect brush tension 22 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 Table J 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 known as threading will result 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 cleaner Oil or grease can be removed with a cloth moistened with mineral solvent Be sure not to get any solvent on the commutator and ob
5. 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 Maximum protection to windings and interior of machine by preventing grease leakage from bearing housing 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 DC Motors 19 Most commonly used bearings are e Single row open ball bearings for coupled and belted duty for frames C210ATZ C250ATZ e Single row open ball bearings for coupled duty for frames C280ATZ C440ATZ e Cylindrical roller bearings at drive end for belted duty on frames UC280ATZ UC440ATZ 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 e Contaminated grease e Insufficient grease or excessive amount e Incorrect grease e Excessive load or thrust due to misalignment or motor overload e Loose bearings e Bearing failure e Excessive ambient temperature Replacement bearings should be ordered from Allen Bradley in order to obtain the same carefully sele
6. 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 ab com drives motors Installation DC Motors 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 and 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 Natio
7. 50 degrees F Place bearing onto shaft and push home to bearing shoulder Hold it in place for a minimum of 30 seconds After bearing 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 16 24 DC Motors Parts Identification C210ATZ C440ATZ gin n aa aa E Sot EN AR a a il II Conduit Boxes Conduit box on C210ATZ C400ATZ is located on the frame at the commutator end Brush Rigging and Brush Holders The brush holders are of constant pressure design and do not require nor are capable of adjustment over the life of the brushes Bracket Re assemblY To obtain proper planity between the integral mounting feet on the front and back end brackets a smooth level surface should be used to align the brackets when they are assembled to the frame 9 2S DO OO EG O OO n e T aa Mn 5 wl Na i ii Number Description Number Description 1 Outer Cover FE 13 Field Coil with Pole 2 Grease Plug FE 14 Armature Coil 3 Ball Bearing FE 15 Winding Support 4 Bearing Cap FE 16 Inner Fan 5 Rocker 17 Bracket BE 6 Bracket FE 18 Bearing Cap BE 7 Brush 19 Ball Bearing BE 8 Brush Holder 20 Grease Plug BE 9 Commutator 21 Shaft Key 10 Field Coil with Pole 22 Shaft 11 Armature Core 23 Conduit Box 12 Frame
8. B CONTROLMAITCHED Variable Speed Solutions Installation Operation and Maintenance Manual DC Motors e Frames C210ATZ C440ATZ e Specifically designed for operation from rec tified power Rockwell Automation 2 DC Motors General Description Table of Contents 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 enclosure horsepower and speed ratings overload and voltage in accordance with NEMA Standards A wide variety of modifications enclosures and accessories is available with the construction and operation of this equipment and the hazards involved should install adjust operate and or service this motor Read and understand this manual in its entirety before proceeding Failure to observe this precaution could result in personal injury or loss of life ATTENTION Only qualified electrical personnel familiar Receiving and Handling ccceeeeeeeeeen eee 3 Installation Location and Air Supply n on 4 Power Supply naonana 5 Conduit BOX aoaaa a 6 Connections aicce a 6 Grounding s seanna 8 Mounting saesae 8 DRO ie orca ae eee E E an 9 Shipping Blocks nnna 10 Motor Application Data cece cece ee 10 Operation BAlANCO oeri sereine a E eanes 13 Series Wound Motors 00 ce
9. To guard against personal injury and or A machine damage observe the following precautions before initial start up 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 23 fields are correct See Checking Relative Polarity of DC Motor Fields on page 15 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 C on page 10 Motor control circuitry must prevent motor speeds from exceeding the stated values 14 DC Motors In addition to observing the above precaution all precautions Attentions mentioned in this document should be observed e The armature should rotate freely and be clear of any 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 a
10. approximately 1 16 and polish Adjust brush holders for approximately 3 32 clearance to commutator The new 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 C210ATZ 5 03 127 8 4 59 116 6 C250ATZ 5 78 146 8 5 34 135 6 C280ATZ 6 53 165 9 6 09 154 7 C320ATZ 7 53 191 3 7 09 180 1 C360ATZ 8 70 221 0 8 26 209 8 C400ATZ 9 55 242 6 9 06 230 0 C440ATZ 10 78 274 0 10 31 262 0 The commutator should be replaced if the final diameter would have to be turned down to a value less than minimum limits Table J DC Motors 21 Commutation Problem Quick Check Chart Symptom 1 Excessive sparking at motor or generator commutator Identified By Sparking Possible Cause 1 Oo ON DOH A O MN Dirty or corroded commutator due to dirt ambient contaminants oil or oil mist etc Brushes incorrectly seated High or feather edged mica Faulty machine adjustment Interpoles failed or improperly adjusted Loss of brush spring tension Brushes sticking in brush holder Unit overload Defective commutator or armature 10 Unequal spacing of holders around commutator 2 High commutator bars produce a rough commutator Generally associated with sparking and noisy operation of the brushes on the commutator 1 Loose commutator 3 Low commuta
11. at the maximum speed at which the machine will operate Failure to observe these precautions could result in personal injury A ATTENTION The machinery builder and or user are The speeds given in Table C 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 AC 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 C Maximum Safe Speed Frame Diameter Maximum Safe Speed C210ATZ 4500 RPM C2512ATZ 4500 RPM C2514ATZ 4500 RPM C2515ATZ 3400 RPM C2812ATZ 4500 RPM C2813ATZ 4000 RPM C2815ATZ 3400 RPM C3210ATZ 3600 RPM C3212ATZ 3600 RPM C3214ATZ 3600 RPM C3612ATZ 3400 RPM C3613ATZ 3200 RPM C400ATZ 2800 RPM C440ATZ 2450 RPM With special construction maximum safe speed may differ from the above values In all cases the 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 DC Motors 11 Minimum V Belt Sheave Diameters Application of Pulleys Sheaves Sprockets and Gear
12. brushes located in the 12 and 6 o clock position 5 Return rocker to original position and change brushes in the 3 and 9 o clock position 6 Re align the neutral setting mark on the rocker ring in line with the mark on the bracket boss 7 Tighten the four hex head cap bolts which hold the rocker ring to the bracket 8 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 9 Install the hand hole covers to each side of the commutator bracket ATTENTION To guard against personal injury or death A ensure 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 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 to 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
13. cted bearing as the original Bearings should never be exposed 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 C210ATZ C250ATZ are the same regardless of whether application is coupled or belted Belted duty for frames UC280ATZ UC440ATZ requires the use of roller bearings Coupled duty uses ball bearings 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 Brush Changing Procedure 1 Remove hand hole covers from each side of the commutator end bracket 2 Loosen four 4 hex head cap bolts which hold the rocker ring assembly to the bracket 3 Brushes are removed from the holder by lifting the brush finger and removing the hex head cap bolt which secures the brush lead to the holder New brushes are installed by following the reverse procedure 20 DC Motors 4 Rotate the rocker ring by hand 90 degrees to replace
14. d 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 to indicate motor overheating Thermostat contacts must be connected in the motor control or indicating circuit Failure to connect the thermostat leads will void the motor warranty Thermostat contact ratings are listed below Motors having thermistors or resistance temperature detectors to indicate motor over temperature must have these devices connected in the proper control circuit to protect the motor Maximum Voltage 250V 60 Hz Rated Current 6 3 amps Maximum Breaking Current 20 amps DC Motors Important 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 Grounding 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 A ground lead is provided inside the terminal box Mounting Motors must be mounted on a rigid solid base or foundation Poor base construction may cause resonances in the mo
15. e 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 force 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 A Operation DC Motors 13 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 Standard Dynamic Balance Limits Highest Rated Speed Maximum Amplitude 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 ATTENTION
16. ed field weakened speed range motors should have the direction of rotation specified Drive C210ATZ C320ATZ frame motors are supplied with a shaft suitable for a belt or coupled drive C400ATZ and C440ATZ frame sizes will be supplied with a short shaft for coupled drives unless specified for belt duty 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 sheave must be placed as close as possible to the motor bracket ATTENTION To guard against personal injury and or machine damage caused by incorrect motor rotation verify direction of 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 10 DC Motors Motor Application Data 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
17. eeling 380 volts 50 Hz AC input to bridge and a 12 millinenry choke to be added externally 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 frame 180 around the shaft axis and reconnecting the brush stud leads contact factory for reconnecting brush stud leads To obtain proper planity between the integral mounting feet on the front and back end brackets a smooth level surface should be used to align the brackets when they are assembled to the frame Connections Important If motor has parallel leads all lugs with the same marking For example Al Al 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 dF S1 j F2 St F2 Generator A1 S2 A1 e S52 2 F1 429 VF St aF s gt F If mach
18. enee 13 Motor Start Up oaen anaana 13 DC Motor Field Heating nananana 14 Checking Relative Polarity of DC Motor Fields 15 Maintenance INSPOCHONS ee eeii reiini ded EE EAEE 16 Cleanliness ioca 16 Lubricator a EA Ste ayes 16 Repacking Bearings or Greasing New Bearings 18 Barings cise ene onra EP EEEO EM 18 EE e a E E bie EE EE A ek 19 Commutator meei eptir a a a E a 20 COMmmMutation moies eree e reek 12 WINGINGS sasiee ig chee ebb es a 22 Filters Cleaning 29 025 0 iat hits i dwndkaarewees dws 22 Brakes origioe E N a avedies 22 Disassembly and Reassembly Instructions Air Gap And Shimming 0 cece eee eee 23 Axial tO een en sai idridpuna 23 Anti Friction Bearing Assemblies 23 Bearing Replacement 0 eecee eee e eee 23 Conduit Boxes 00 cece cece eee ee 24 Brush Rigging and Brush Holders a an 24 Parts Identification aaaaaannnanannnnnnnnnna 24 Receiving and Handling DC Motors 3 Acceptance Thoroughly inspect this equipment before accepting 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 a
19. er shafts and roller bearings when belted drives are specified Table D 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 12 DC Motors Table E Axial Thrust Capacity Horizontal Mounting Vertical Mounting Frame Units 2500 RPM 1750 1150 850 2500 1750 1150 850 RPM C210AT Ibs 510 565 640 700 535 137 590 137 665 137 725 137 kg 232 257 291 318 243 62 268 62 302 62 330 62 C250ATZ Ibs 535 595 675 725 580 255 640 255 720 255 770 255 kg 243 270 307 330 264 116 291 116 327 116 350 116 C280ATZ Ibs 650 725 825 890 715 360 795 360 890 360 955 360 kg 295 330 375 405 325 164 325 164 405 164 434 164 C320ATZ Ibs 845 940 1065 1150 920 448 1020 448 1155 448 1235 44 kg 384 427 484 523 418 204 464 204 525 204 561 204 C360ATZ Ibs 1045 1160 1315 1420 1160 661 1280 661 1445 661 1555 66 kg 475 527 598 645 527 300 582 300 657 300 707 300
20. 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 DC Motors Table A Air Volume Chart Base Speed Air Volume _ Static Pressure Frame RPM CFM Inches of Water C2113ATZ ALL 300 2 25 C2115ATZ ALL 290 4 1 C2512ATZ ALL 425 2 0 C2514ATZ ALL 385 3 4 C2515ATZ ALL 385 3 4 C2812ATZ ALL 550 3 25 C2813ATZ ALL 530 3 75 C2815ATZ ALL 530 3 75 C3210ATZ ALL 800 3 5 C3212ATZ ALL 800 3 5 C3214ATZ ALL 700 4 0 C3612ATZ ALL 1000 4 0 C3613ATZ ALL 950 5 1 C400ATZ ALL 1200 40 C440ATZ ALL 1650 7 0 ATTENTION To guard against premature brush wear due to silicone vapors Do Not use silicone sealing compounds in the vicinity of the motor or its air supply 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 let
21. hrust demands may however require a different bearing system Hand hole covers can be interchanged as necessary DC Motors 9 Important Vertical mount hand hole 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 hand hole covers from Allen Bradley 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 should use a D Flange In addition frame sizes C2515AT and C2815AT require additional support may 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 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 Extend
22. ine has no series field disregard S1 and S2 above For machines with special windings refer to motor or generator and controller diagrams Important Figure 2 DC Motors 7 If motor is supplied with dual voltage shunt fields connections must be made for appropriate voltage DC Motor with Dual Voltage Field Rotation Facing Commutator End Field Connection CCW CW High A1 0 F1 Al F Voltage A F2 420 F S1 l l F11 S1 l F S2 F22 S2 F Low A1 F1 Ale F Voltage A2 e F2 420 E St Le F11 Sie F s20 lero 2e Ler Thermostat Thermal Protector Important Important When motors are provided with thermal protection typically thermostats it is important to properly connect and apply the devices This will ensure that the motor is properly protected from being operated if thermal limits are reached and or exceeded The control system must be configured to reduce the motor load and or shut down the motor control system to allow the motor to cool to a level within acceptable operating ranges If the motor is operated with the thermal protective devices tripped indicating an over temperature condition the motor insulation could be damaged and complete failure of the motor insulation is possible In the event of motor failure due to an over temperature condition Rockwell Automation requires that motor thermal protective devices when supplied be adequately monitored an
23. 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 DC Motors 15 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 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 motor temperature will exceed the normal class F rise with resulting reduction in insulation life if operated below approximately 90 of base speed at rated voltage for prolonged periods Contact Allen Bradley for torque derating curves for motors operated continuously below base speeds Checking 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 acr
24. n Interval Months 2 Maximum Normal Standard Severe Extreme Operating Speed RPM Frame Service Service Service 3450 and higher All 9 4 1 2400 3449 C210ATZ C250ATZ 24 9 3 C280ATZ C400ATZ 9 3 1 1700 2399 C210ATZ C320ATZ 36 12 3 C360ATZ C400ATZ 18 6 2 UC360ATZ UC400ATZ 9 3 1 800 1699 C210ATZ C320ATZ 36 24 8 C360ATZ C400ATZ 36 12 3 UC360ATZ UC400ATZ 18 6 1 500 799 C210ATZ C320ATZ 48 36 12 C360ATZ C400ATZ 36 24 8 UC360ATZ UC400ATZ 18 12 4 499 and lower C210ATZ C440ATZ 48 36 12 UC360ATZ UC440ATZ 24 18 6 1 Maximum speed occupying more than 30 of operating time 2 For Tandem drives increase frequency of lubrication by multiplying values by 0 8 Frames C210ATZ C440ATZ These motors are designed to route new grease directly into the bearing The relubrication periods shown in Table I 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 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 18 DC Motors ATTENTION To guard against personal injur
25. n 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 replace ment 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 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 injury 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
26. nal Electric Code Users must observe these regulations and consult with local code inspection and enforcement agencies to insure compliance 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 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
27. ny 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 16 may 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 result in personal injury A ATTENTION Surface temperature of the motor enclosure DC Motor Field Heating ATTENTION To guard against motor damage caused by A 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
28. oss 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 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 if 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 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 toge
29. s 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 Minimum Pitch Diameter for Drives Other Than V Belt To obtain the minimum pitch diameters for flat belt timing belt chain and gear drives apply the multiplier given in Table D to the minimum sheave diameter calculated for V belt drives Shaft Extension and Method of Drive Frames C210ATZ C250ATZ are supplied with a shaft and bearing system suitable for either coupled or belted drives Frames C280ATZ C440ATZ are supplied with larg
30. serve 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 standard filter is a six layer woven steel fabric The following procedure should be used to clean these filters 1 For light accumulations of dust use compressed air to clean 2 For moderate accumulations water may be used 3 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 Disassembly and Reassembly Instructions DC Motors 23 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 pos
31. sible damage or harm to either machine and or maintenance personnel Air Gap And Shimming Frames C210ATZ C400ATZ 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 Interpoles Excluding the C440ATZ frame interpoles are an integral part of the frame and do not require nor are they capable of shimming Axial Float Motors have a wave spring washer between the drive end bracket and bearing The commutator end bearing is positioned axially by a float restricting inner cap Axial float including bearing internal clearance should be within the limits listed below Axial Float Frame Maximum Minimum C210ATZ C440ATZ 1 29 mm 0 051 in 0 33 mm 0 013 in Anti Friction Bearing Assemblies The bearings are positioned and secured in a machined cavity in the end brackets Open type ball bearings are used for direct coupled and belt drive applications for frames C210ATZ C250ATZ and are protected by inner caps at both ends Frames UC360ATZ C440ATZ employ a cylindrical roller bearing on the drive end for belt drives and a ball bearing for coupled service 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 1 2 hour at 121 degrees C 2
32. ter designation prior in the alphabet to the letter stamped on the nameplate with no loss in nameplate rating 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 DC Motors Description Code DC generator battery or twelve pulse cycle 6 phase full control A Six pulse cycle 3 phase full control 230 or 460 volt 60 Hz input to rectifier C Three pulse cycle 3 phase semi bridge half control 230 or 460 volt 60 Hz input to D rectifier Three pulse cycle 3 phase half wave single way 460 volt 60 Hz input to rectifier E Two pulse cycle 1 phase full wave bridge circuit with 2 controlled rectifiers and 2 K uncontrolled rectifiers with free wheeling rectifier 230 volt 60 Hz input 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 wh
33. ther at the motor and not brought to the controller 16 DC Motors Maintenance ATTENTION Internal parts of this motor may be at line A 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 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 machines 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 Amount of grease to be added to motors is shown in Table G See Table I for relubrication interval 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 degrees F mae a ae 3 Texaco Inc Premium RB Minimum Starting Temperature Shell Oil Co Aeroshell 7 60 degrees C 76 degrees F Roller Bearing Motors Operating Temperature Chevron Oil Black Pearl EP No 2 25 to
34. tor bars produce rough commutator Generally associated with sparking and noisy operation of the brushes on the commutator 1 Loose commutator 2 High mica 3 Open or high resistance connection at commutator 4 Streaking or threading of commutator surface Rough commutator with associated sparking Fine lines in brush track Low average current density in brushes due to light machine loading Contaminated atmosphere Oil on commutator or oil mist in air Humidity too low Lack of film forming properties in brush Brush too abrasive 5 Bar etching or burning Rough commutator with associated sparking and eventual flashover ar won 9O oO F amp F OMN High mica Operation of machine with brushes off neutral Commutator dirty Incorrect spring tension Machine overload or rapid load change such as plugging 6 Bar marking at pole pitching spacing e Two bars marking 180 degrees C 356 degrees F apart on 4 pole machine at start 2 Three bars marking 120 degrees C 248 degrees F apart on 6 pole machine at start 3 As pitch bar marking progresses it will eventually show at all bars on the machine 4 Associated sparking and eventual flashover A O N gt Shorted commutator bars or coils Open armature or field circuit Unequal air gap Cyclic disturbance either electrical or mechanical 7 Bar marking at slot pitch spacing
35. tor 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 B Recommended Torque Recommended Torque Hole Diameter Bolt Size and SAE 5 SAE 8 Frame mm in Thread N m Ib ft N m Ib ft C210ATZ 11 2 0 44 3 8 16 45 50 33 37 64 72 47 53 C250ATZ 14 2 0 56 1 2 13 113 126 83 93 159 179 117 132 C280ATZ 14 2 0 56 1 2 13 113 126 83 93 159 179 117 132 C320ATZ 17 5 0 69 5 8 11 210 239 155 176 271 338 200 249 C360ATZ 20 6 0 81 3 4 10 372 420 274 310 527 597 389 440 C400ATZ 26 9 1 06 7 8 9 588 659 434 486 835 934 616 689 C440ATZ 26 9 1 06 7 8 9 588 659 434 486 835 934 616 689 Belted Drive Motor slide bases or rails when used must be securely anchored to 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 10 Coupled Drive 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 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 t
36. y or death from rotating parts or electrical shock relubrication should only be performed while the motor is stationary and disconnected from the power source Remove grease drain plug located opposite the grease inlet Using a manual grease gun pump in the recommended grease in the amount shown in Table G This amount of grease will provide an ample supply of lubricant between lubrication periods as determined from Table I for the condition listed in Table H 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 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 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 around the inboard side of the bearing between bearing and inner cap Assure that grease adheres to balls or rollers Apply one bead of grease around outboard side of bearing making sure grease adheres to balls or rollers Completely fill grease inlet and outlet passage holes with grease Fill outboard bearing cavity 60 to 90 full of grease If
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