service manual
Contents
1. ee 6 DETAILED CIRCUIT OPERATION OF CONTROLLER 1212 TROUBEESHOUOPING ees hen MS ate dt tha itt ca e beer da aL E SpA 13 REPAIR PROC EID RS 52 oe ee A eel 14 17 REPLACEMENT PARTS LISTING 18 19 CALIBRATION 20 FUNCTIONAL TES s est Ae cA 20 Ae 23 24 APPENDIX OLD SERVICE MANUAL A 1299 0442 for 7520 xx drives manufactured before the date code outlined on the next page This service manual is written to cover the Re Designed 7520 xx series drives The new drives can be identified by the manufactures use of a gold colored chassis The previous products had black chassis The 7520 xx have similar electronics hardware Service techniques used on one system will carry over to the other family This also holds true for the OEM model numbers The 7520 xx and 900 xx series drives that were manufactured prior to H00005767 excluding s H00001068 thru H00001114 as listed on the drives serial number code are covered under the old service manual part number A 1299 0442 see appendix Service for this product is performed at three levels the customer distributor COLE PARMER and factory depot repair This manu2. 1 and RC network amp suppress line noise generated externally and internally by motor and power bridge Output Drive A Motor power bridge consists of CR 3 CR 4 Q 1 Q 2 Diode CR 5 bypasses the inductive current surges of the motor when the power bridge shuts off The output bridge is routed through FWD OFF REV by J 9 J 10 J 11 J 12 J 17 J 18 connecting switch contacts to allow motor reversal and is brought out at 7 1 and J 2 of the pcb B Resistor capacitor combination consisting of R 5 and C 2 which forms a snubber network for commutator noise suppression Control Section A Motor speed is set by panel mounted pot R 29 is obtained by regulating the 22VDC supply with R 13 and CR 11 to approximately 12VDC This is routed through network R 28 and R 29 to DC ground Adjustment pot R 28 sets maximum motor speed approx 10VDC at TP 1 C Components R 14 CR 9 C 6 control acceleration and deceleration of motor RPM D Set speed is controlled and regulated by differential amp U7 A and related components R 15 C 7 R 17 R 2 R 3 As motor load increases back EMF picked off drive output resistor network R 2 and R 3 TP 3 drops off This is fed through R 17 to pin 2 of U1 A causing TP 2 to charge integrator capacitor C 10 via R 18 to advance the SCR firing angle E Current limit of circuit is accomplished by monitoring the voltage drop of current sense res
3. 4 4 1 Operating Temperature 0 C 40 C Storage Temperature 45 C 65 C Humidity non cond 10 90 Altitude 2000 m 4 4 2 Chemical resistance All materials withstand standard cleaning solvents Materials used in the construction are ABS plastic case with a polyester label gold irridite coated aluminum chassis and zinc plated screws 4 4 3 Vibration Withstands standard freight shipment Rail Air Sea and Paved Roads when packed in specified shipping container Secured Cargo Electromagnetic Compatibility EMC Meets immunity requirements of EN 61326 1 A1 1998 for residential commercial and light industry applications to comply with EC EMC Directive for the European Union CE mark 24 APPENDIX SexsSERVICE MANUAL MODELS 7520 40 Unified Drive System 600 rpm 115v single turn 7520 45 Unified Drive System 600 rpm 230v single turn 7520 47 Unified Drive System 600 rpm 230v single turn CE mark 7520 50 Unified Drive System 100 rpm 115v single turn 7520 55 Unified Drive System 100 rpm 230v single turn 7520 57 Unified Drive System 100 rpm 230v single turn CE mark 7520 60 Unified Drive System 300 rpm 115v single turn 7520 65 Unified Drive System 300 rpm 230v single turn Information contained in this manual is proprietary to the BARNANT COMPANY division of COLE PARMER INSTRUMENT COMPANY INC No reproduction for other than the intended use of maintaining the product described herei
4. on 115 volt units or SCR Q 8 on 220 volt units to fire the power bridge SCR Q 1 amp Q 2 R 7 limits the gate current while CR 6 blocks back conduction of Q 3 or Q 8 31 TROUBLESHOOTING Repairs on this unit are basically confined to either the units control PCB and or drive motor assembly Where possible swap in known good parts to localize and isolate the problem The following is a list of possible problems and remedies UNIT DOES NOT TURN ON NO POWER LIGHT 1 fuse blown replace fuse 2 power cord not connected properly check amp replace 3 FWD OFF REV switch failure replace switch ASSY 4 unit connected to dead outlet verify supply is HOT UNIT BLOWS FUSES 1 motor drive failure check using known good motor 2 defective controller pcb returm replace to factory 3 wrong fuse installed check fuse rating MOTOR WILL NOT REVERSE 1 defective FWD OFF REV switch replace switch ASSY MOTOR WILL NOT RUN assumed functional motor 1 defective FWD OFF REV switch replace switch ASSY 2 defective controller PCB ASSY replace main controller PCB ASSY LOSS OF SPEED CONTROL OR IMPROPER SPEEDS 1 defective controller PCB ASSY replace main controller PCB ASSY 2 unit out of calibration recalibrate controller MOTOR IMMEDIATELY RUNS WHEN POWER IS APPLIED 1 power output triacs shorted replace main controller PCB ASSY FOR ADDITIONAL INFORMATION REGARDING THE UNIT PLEASE REFER TO THE FOLLOWING
5. 7520 57 230 volts 200 volts 7520 65 230 volts 200 volts MAXIMUM 130 volts 130 volts 130 volts 260 volts 260 volts 260 volts 260 volts 260 volts LINE FREQUENCY All models SINGLE PHASE 50 60 hertz TEMPERATURE amp HUMIDITY MINIMUM OPERATING TEMPERATURE 0 degrees c STORAGE TEMPERATURE 45 degrees c HUMIDITY NON COND 0 CODE RATINGS MAXIMUM 40 degrees 65 degrees 90 All controller housings meet INTERNATIONAL ELECTRIC CODE 34 5 IP CODE 53 RATING Note SIMILAR TO NEMA 5 AND 12 RATINGS 38
6. GENERAL OVER VIEW A The 77521 series controller board employs modular SMT technology see figure 2 to provide a single board solution employing an SCR based power amplifier to drive permanent magnet motors up to 1 HP This board also incorporates circuitry to allow remote speed control through voltage or current as well as control through contact closures All of the board features of the 7520 are used in this design therefore the detailed descriptions of circuitry that follow will only outline the major differences between the two Power Supply A The 22 volt non isolated supply is derived by 100 VDC at TP 8 dropped by resistor network R117 R132 R133 R134 R135 R136 these are multiple smt style resistors and regulated to approximately 22 VDC at TP 6 by VR4 The voltage will charge C5 through CR8 to filter the ripple and produce a regulated supply B The 15 volt non isolated supply is derived by tapping off C5 through R33 and regulated by VR2 Capacitor C16 filters any ripple C A separate 15 volt supply used to drive the circuitry on the isolated side of the circuits is derived for transformer T1 rectified by D1 D4 filtered and bypassed by C23 C24 then fed into regulator U8 The 15 volts is set by R106 R107 and filtered by C20 This voltage is available at J16 pin 1 Control Section In this controller all user adjustable controls e g speed pot and remote features are isolated from the
7. may be used to roughly calibrate an out of spec unit BEFORE PROCEEDING ANY FARTHER PLEASE NOTE ALL WARNINGS AS LISTED IN THE SAFETY CONSIDERATIONS SECTION 35 TOOLS REQUIRED A 1 Phillips screw driver B non metallic pot tweaker C hand held tachometer Proceed as follows 1 Remove the three pan head screws on each side of the unit s cover 2 Position top half of cover so that adjustment pots are accessible 3 Plug unit into the appropriate line voltage If this be done through an adjustable variac set to nominal value eg 120 for 115 volt units or 240 for 230 volt units 4 Turn unit on set speed control for maximum 5 Measure shaft RPM of driven device turn pot R 28 multi turn to obtain proper RPM 600 RPM 605 RPM for 600 RPM units 100 RPM 105 RPM for 100 RPM units 300 RPM 305 RPM for 300 RPM units 6 Pot R 31 is used to set the unit s no load to full load response and therefore should not be field adjusted 7 Seal pot adjustments and reassemble unit 36 FUNCTIONAL TESTS A Power Up controller at specified line voltage B Verify that controller drives motor properly C Refer to the CALIBRATION Section for additional information regarding the unit 37 SPECIFICATIONS LINE VOLTAGES MODEL NOMINAL MINIMUM 7520 40 115 volts 90 volts 7520 50 115 volts 90 volts 7520 60 115 volts 90 volts 7520 45 230 volts 200 volts 7520 47 230 volts 200 volts 7520 55 230 volts 200 volts
8. 01 7520 50 D 2763 0001 7520 60 D 2763 0005 230Volt Models MODEL PCB 7520 45 D 2763 0002 7520 47 D 2763 0008 7520 55 D 2763 0002 7520 57 D 2763 0008 7520 65 D 2763 0006 REFERENCE SCHEMATIC D 2761 D 2761 D 2761 REFERENCE SCHEMATIC D 2761 D 2761 D 2761 D 2761 D 2761 The following is a list of commonly used parts applicable to all the above model LISTINGS DESCRIPTION BARNANT part Speed Adjustment Knob single turn 1083 0056 Rubber Foot large FRONT PANEL OVERLAYS MODEL BARNANT part 7520 40 D 2553 7520 45 D 2553 7520 47 D 2553 7520 50 D 2553 7520 55 D 2553 7520 57 D 2553 7520 60 D 2553 7520 65 D 2553 B 1390 0002 34 CALIBRATION After repairs are made the unit must be tested to assureproper performance to specifications In many cases factory QC check out procedures can be used by servicing personnel to accomplish this For calibration procedures please refer to the following CAL SPECIFICATION listings table appropriate to the model that is being calibrated MODEL CAL SPECIFICATION 7520 40 1352 7520 45 CAL 1352 7520 47 1352 7520 50 CAL 1352 7520 55 CAL 1352 7520 57 1 1352 7520 60 CAL 1612 7520 65 CAL 1612 Additional technical specifications are available in the units OPERATOR MANUAL Because this manual is covering approximately four different models exact calibration procedures will differ between each unit However the following procedure
9. 4 by an emitter follower Q 4 amp R 25 amplifier which discharges integrator C 10 retarding the SCR firing angle The resultant firing angle will be proportional to the difference between the torque reference charging current R 18 and the torque feedback discharging current R 25 The SCR will fire when the integrator C 10 voltage is equal to the PUT Q 9 reference voltage VR 3 R 11 amp R 12 Line synchronization is achieved by allowing the reference voltage to drop to zero 10 volt window with each line cross thereby discharging C 10 through Q 9 C 10 amp Q 9 form a relaxation oscillator whose period is proportional to the rate of charge of C 10 When the voltage across C 10 is equal to the reference voltage the PUT Q 5 is forward biased and will conduct discharging C 10 through the base emitter junction of buffer Q 6 R 9 bypasses any leakage current while C 11 filters out noise pulses G The pulse output of the relaxation oscillator C 10 amp Q 9 is buffered and amplified by Q 6 and level shifted by a Darlington pair Q 3 amp Q 8 on 115 volt units or Q 8 amp Q 7 on 220 volt units fire the Power Bridge SCR Q 1 amp Q 2 R 7 amp R 29 limits the gate current while CR 6 amp CR 12 blocks back conduction of the Darlington pair H For a detailed view of these signals see figure 3 waveform and related descriptions DETAILED CIRCUIT OPERATION 77521 XX SERIES CONTROLLERS
10. 7520 40 7520 47 7520 50 7520 57 7520 60 7520 67 77521 40 77521 47 77521 50 77521 57 900 1076 900 1077 900 1268 900 1273 900 1274 B MANUAL EES Es MODELS Unified Masterflex Drive 600 RPM 115 V Unified Masterflex Drive 600 RPM 230 V ce Unified Masterflex Drive 100 RPM 115 V Unified Masterflex Drive 100 RPM 230 V ce Unified Masterflex Drive 300 RPM 115 V Unified Masterflex Drive 300 RPM 230 V ce Unified Masterflex Drive w 4 20 mA 600 RPM 115 V Unified Masterflex Drive w 4 20 mA 600 RPM 230 V ce Unified Masterflex Drive w 4 20 mA 100 RPM 115 V Unified Masterflex Drive w 4 20 mA 100 RPM 230 V ce OEM Drive MILLIPORE 600 RPM 115 V OEM Drive MILLIPORE 600 RPM 230 V ce OEM Drive Drive Tech 300 RPM 115 V OEM Drive Spectrum Pump System 600 RPM 115 V OEM Drive Spectrum Pump System 600 RPM 230 V ce Information contained in this manual is proprietary to the BARNANT COMPANY division of COLE PARMER INSTRUMENT COMPANY INC No reproduction for other than the intended use of maintaining the product described herein is permitted without the permission of BARNANT Barnant Company Division of Cole Parmer Instrument Company Inc 625 East Bunker Court Vernon Hills Illinois 60061 1844 847 549 7600 847 247 2929 Fax 800 323 4340 A 1299 0934 Edition 02 TABLE OF CONTENTS PAGE INSRODUGIION SE EG DS GE EE 4 SAFETY CONSIDERATIONS 06 ote eet 5 THEORY OF
11. A 1299 0110 operators manual 32 REPAIR PROCEDURES TO DISASSEMBLE UNIT PROCEED AS FOLLOWS A Remove the three pan head screws on each side of the unit s cover B Lift off molded housing TO REASSEMBLE UNIT PROCEED AS FOLLOWS A Slide on molded housing B Install the three pan head screws on each side of the unit s cover TO REPLACE MAIN CONTROL PCB ASSEMBLY A Follow the steps outlined in DISASSEMBLE UNIT B Replace main pcb assembly C Note wiring of chassis as follows 1 BROWN of corcom line filter to J 3 2 BLUE of corcom line filter to J 4 3 RED of drive motor to J 1 4 BLACK of drive motor to J 2 5 Follow steps in TO REPLACE FWD OFF REV SWITCH Note switch does not have to be removed from housing D Check calibration per applicable CAL specifications E Follow the steps outlined in ASSEMBLE UNIT TO REPLACE FWD OFF REV SWITCH A Follow the steps outlined in DISASSEMBLE UNIT B Pull handle off switch ASSY C Remove retaining hardware from switch D Note wiring of chassis as follows 1 ORANGE 1 9 2 ORANGE BLACK J 10 3 YELLOW si pl DRED ske 12 5 BROWN J 13 6 BLACK eis 14 Ty GRAY J 17 8 VIOLET J 18 9 BLACK WHITE J 19 33 REPAIR PROCEDURES The following is a list of stockable main control pcb assemblies and their reference schematic diagrams for all indicated models 115Volt Models MODEL PCB 7520 40 D 2763 00
12. ac line The final output from the opto coupler isolator drives the input of the aforementioned controller A Motor speed is set by front panel pot connected to J8 B Front panel speed reference voltage is generated by divider network R65 R56 and R53 to DC ground Adjustment pot R 65 sets maximum motor speed approx 4 0VDC at J16 pin3 C The 4 volt signal that is set above is routed through analog switch network SW1 A amp SWIC which is the selection network for front panel speed or remote speed select and the foot switch control Switch SW1 A works opposite of SW1 B when local remote switch is in the LOCAL position a low is placed at pin5 SW1 B turning it off The low is prevents conduction of D8 allowing pull up R75 to enable SW1 A selecting the front panel speed reference When local remote switch is in the REMOTE position a high is placed at pin5 SW1 B turning it on selecting the remote speed inputs The high causes conduction of D8 transistor Q11 conducts pulling pin13 SW1 B low deselecting the front panel speed reference In this mode the user can select either front panel or remote speed references by grounding J6 pin4 interface connector D The foot switch control works in a similar manner as above When local remote switch is in the REMOTE position a low is placed at pin6 SW 1 B turning it off The low is generated by Q10 conduction through D7 pull up R70 this prevents the speed reference volta
13. agnet DC motor The bridge will conduct current only when the power line voltage exceeds the voltage across the motor terminals The power to the motor can therefore be controlled by varying the point at which the bridge starts to conduct relative to the phase of the line voltage The phase angle at which the bridge starts conducting is controlled by an inner torque outer speed regulator loop The speed of the motor is directly proportional to the back EMF generated by the motor Comparing the voltage across the motor terminals against the speed reference signal at the center tap of the front panel speed control pot R 29 U 1 generates a torque reference signal The torque supplied by the motor is directly proportional to the current supplied to the motor U1 amplifies the voltage drop across a load resistor providing a signal proportional to the current supplied to the motor The peak value of the signal is subtracted from the torque reference signal by Q4 The resulting torque error signal charges C10 firing Q6 and the power bridge SCR s and CI provide transient voltage protection from power line surges caused by other power conversion equipment and lightning strikes R5 and C2 provide transient protection from surges created by motor brush noise and FWD REV switching CR4 Q1 and Q2 form the main power bridge for the motor CR5 provides a current path to allow shut off of SCR s Q1 and Q2 R2 and R3 provide voltage feedback an
14. al describes distributor COLE PARMER service procedures Customer service procedures are described in the operator s manual Customers are encouraged to perform service as described in the operators manual as well as in special circumstances where special skills and safety are not considerations To use this manual begin with the troubleshooting section to isolate the fault to a replaceable part The functional description and checkout procedure sections are also helpful in determining the faulty part Distributor COLE PARMER repair is limited to replacement of modules as detailed in the replacement parts list section The repair procedure section details disassembly and assembly procedures After repair the product should be calibrated and checked for proper performance Please refer to the operators manual PT A 1299 0860 for A APPLICATIONS DATA B PRODUCT DESCRIPTION C INSTALLATION D SETUP E OPERATION F USER CALIBRATION G USER TROUBLESHOOTING amp MAINTENANCE H ACCESSORIES L SPECIFICATIONS Servicing must be performed only by personnel trained and skilled in the methods of troubleshooting and repair of electro mechanical products Use of procedures other than those described in this manual may result in a safety hazard to service personnel and or customers When servicing any component of this unit be absolutely certain that all power to circuitry is removed If any functional checks are to be performed wh
15. bber network for commutation noise suppression Control Section A Motor speed is set by front panel pot connected to J6 B A VREF is obtained by regulating the 22VDC supply with R 13 and CR 11 to approximately 12VDC This is routed through network R 33 and R 30 to DC ground Adjustment pot R 33 sets maximum motor speed approx 10VDC at TP 1 C Components R 13 CR 9 and C 6 control acceleration deceleration of motor RPM D Set speed is controlled and regulated by differential amp U1 and related components R 15 C 7 R 17 and R 2 R 37 R 3 All scaling is done at 5volts full scale for all op amp circuits As motor load increases back EMF picked off drive output resistor network R 2 R 37 and R 3 TP 3 decreases from 5 volts This is fed through R 17 to pin 2 of U1 A causing TP 2 to charge integrator capacitor C 10 via R 18 to advance the SCR firing angle until the op amp equalizes its input voltages E Current limit of circuit is accomplished by monitoring the voltage drop of current sense resistor R 4 feeding it through R 19 and R 11 to level amp U1 B and related components As current through R 4 approaches 2 0 amps for 120 volt units 1 0 amps for 240 volt units voltage to TP 4 rises to approximately 5 0VDC This is fed through resistor network R 22 and R 23 at a 2 to 1 ratio into the peak detector CR 10 amp C 9 The output of the peak detector is buffered R 21 amp Q
16. d R4 provides current feedback to the regulator circuits CR1 and CR2 with CR3 and CR4 form the secondary power bridge for the power to the regulator circuits R26 is a voltage dropping resistor from line voltage to the 22V used by the regulators CR7 limits the voltage to 22V CR6 decouples the pulsating DC used to synchronize the SCR firing circuit to the line from the steady DC filtered by C5 used to power the regulator circuits R3 and CRI stabilize the speed reference signal R11 and R12 provide the voltage reference and line synchronization for the PUT Q5 used to fire the power bridge SCR s R14 CR9 and C6 form the soft start circuit which provides a gentle acceleration of the motor R31 and R16 compensate for the voltage drop introduced by the motor armature resistance thereby improving load regulation of the drive CR10 and C09 form a current peak detector which is buffered by R24 004 and form a pulse amplifier and level shifter to fire the power bridge SCR s The SCR used for Q3 in the 220 vac units is configured to act like a high voltage PNP transistor 29 DETAILED CIRCUIT OPERATION Power Supply A AC line is brought in at J 3 and J 4 and routed through FWD OFF REV switch contacts to power bridge consisting of CR1 CR4 B 100 VDC at TP 8 is dropped by series resistor R 26 and regulated to Approx 22 7 VDC at TP 6 by CR 7 C Green LED indicates power ON to circuitry D Varistor
17. de 5 vde for 115 vac units 200 0 vdc 1 0 vde for 230 vac units 5 All other pots are factory adjusted and should not be field adjusted 6 Seal pot adjustments and reassemble unit FUNCTIONAL TESTS A Mate drive motor to specified controller B Power up controller at specified line voltage C Verify that controller drives motor properly D Refer to the CALIBRATION Section for additional information regarding the controller 22 Power Supply Voltage per DSM 8806 90 130 Vrms or 190 260 Vrms 50 60 Hz Single Phase IEC 664 Installation Category II Appliances and portable equipment powered from local branches All drives use modular line cords with IEC 320 CEE 22 connector coupler Female line cord male socket Alternative Line cords is available as Model numbers 50001 68 USA 115V Japanese 50001 70 European 50001 60 Australia 50001 62 Denmark 50001 64 India 50001 66 Israel 50001 72 British 50001 74 Swiss 50001 76 Italian 50001 78 USA 230V Motor Power 0 10 hp Maximum at output shaft Drive Current Max 115 Vrms 2 3A 230 Vrms 1 2A Control Circuit Power 6 watts maximum dissipation 4 3 2 Remote Start Stop amp Remote Local The remote control inputs work with current sinking outputs open collector NPN transistor outputs with or without passive pull up resistors or contact closures to DC common earth ground A continuous active low to the Remote Start Stop inp
18. e fuse 2 Power cord not connected properly check amp replace 3 FWD OFF REV switch failure replace main controller PCB 4 Unit connected to dead outlet verify supply is HOT UNIT BLOWS FUSES 1 Motor drive failure check using known good motor 2 Defective controller PCB replace return to factory 3 Wrong fuse installed check fuse rating MOTOR WILL NOT REVERSE 1 Defective FWD OFF REV switch replace switch assy MOTOR WILL NOT RUN assumed functional motor 1 Defective FWD OFF REV switch replace switch assy 2 Defective controller PCB ASSY Replace main controller PCB ASSY LOSS OF SPEED CONTROL OR IMPROPER SPEEDS 1 Defective controller PCB ASSY Replace main controller PCB ASSY 2 Unit out of calibration recalibrate controller MOTOR IMMEDIATELY RUNS WHEN POWER IS APPLIED 1 Power output triacs shorted replace main controller PCB ASSY For additional information regarding the unit please refer to the following A 1299 0860 operators manual 13 Figure 4 Position cover and chassis as shown Be very care full not to let any switch terminals ground out to chassis TO REASSEMBLE UNIT PROCEED AS FOLLOWS 14 A Reverse the above steps insuring that no wiring is pinched The wiring harnesses should be formed as an upside down P TRAP position inside the enclosure TO REPLACE MAIN CONTROL PCB ASSEMBLY 7520 A Follow the steps outlined in DISASSEMBLE UNIT B Disconnect the wir
19. ge regardless of front panel or remote selection from driving the opto coupler isolation drive By grounding J6 pin7 interface connector the low prevents conduction of D7 transistor Q10 turns off allowing pull up R73 to enable SW1 C allowing the speed reference voltage selected to drive the opto coupler isolation drive E The opto coupler isolation drive consists of OPT1 and U4 B this circuit works by taking a voltage at pin5 U4 B and having the output of the op amp drive the input ird led of OPT1 until the op amp equalizes its input voltages at pin6 Because there is are two detectors within optl one is within the feedback path another in a separate op amplifier U5 B A linear drive voltage will give a linear output ofthe same voltage pin7 U5 B This control voltage typically 0 10 volts will drive the SCR amplifier input This circuit also serves to provide isolation barrier of approx 3500 volts between the grounded and hot referenced control circuits F The linear inputs consist of U3 A dual op amp This is split one for voltage one for current The voltage input enters pin 76 and ground pin3 J6 through R78 The voltage across R78 is divided by 2 and buffered by U3 A to generate 1 5 volt output The current input enters pin2 J6 and ground pin3 J6 through R47 The voltage across R47 is buffered by U3 B to generate a 1 5 volt output G Because the scaling ofthe electronics the outputs
20. gnal is subtracted from the torque reference signal by a transistor The resulting torque error signal charges a capacitor firing the power bridge SCR s for a given line cycle Transient voltage suppression for the line is provided by line to line Mov s Motor brush commutation noise is suppressed using a RC network 600 volt SCR s and 1000 volt diodes make up the power bridge and primary power supply Supply regulation is through a zener diode network SCR switching at zero cross is actually centered on a 10 volt window creating a secondary supply allowing a complete shut off of each SCR This voltage is also used to synchronize the SCR firing circuit to the line A simple RC network provides for a soft start circuit which provides a gentle acceleration of the motor The 77521 xx series drives have an identical motor controller front end with the addition of linear speed control inputs These two inputs take either 2 10 volt dc or 4 20 ma and operate the drive over its full rated speed range The linear inputs generate a 1 5 volt span that is OP amp buffered for common mode up to 15 vdc This voltage is than fed through an offset OP amp to subtract 1 volt from the signal leaving 0 4 volt control signal for speed reference MOS switches select either the front panel control reference voltage or the linear input speed reference to control drive speed This stage also incorporates an additional MOS switch that allows contact c
21. ile power is applied and chassis is disassembled care must be exercised for the following A WARNING A THIS IS A LINE OPERATED DEVICE AND IS NOT ISOLATED FROM GROUND USE OF AN ISOLATION TRANSFORMER IS STRONGLY RECOMMENDED B DO NOT INADVERTENTLY SHORT ANY PART OF THE PRINTED CIRCUIT CARD TO GROUND AS SEVERE DAMAGE WILL RESULT C MAKE ABSOLUTELY SURE THAT ANY TEST EQUIPMENT USED FOR REPAIR IS NOT REFERENCED TO EARTH GROUND The variable speed controller employs a phase controlled rectifier bridge to vary the power applied to a permanent magnet DC motor The bridge will conduct current only when the power line voltage exceeds the voltage across the motor terminals Varying the point at which the bridge starts to conduct relative to the phase of the line voltage can therefore control the power to the motor An inner torque outer speed regulator loop controls the phase angle at which the bridge starts conducting The speed of the motor is directly proportional to the back EMF generated by the motor Comparing the voltage across the motor terminals against the speed reference signal at the center tap of the front panel speed control pot an op amp generates a torque reference signal The torque supplied by the motor is directly proportional to the current supplied to the motor The op amp amplifies the voltage drop across a sense resistor providing a signal proportional to the average current supplied to the motor The peak value of the si
22. ing and hardware as shown in picture Max speed ADJ R83 C Replace control board noting wiring D Check calibration as per applicable CAL specifications E Follow the steps outlined in ASSEMBLE UNIT TO REPLACE MAIN CONTROL PCB ASSEMBLY 77521 15 A Follow the steps outlined in DISASSEMBLE UNIT B Disconnect the wiring and hardware as shown in picture Max speed ADJ R90 C Replace control board noting wiring D Check calibration as per applicable CAL specifications E Follow the steps outlined in ASSEMBLE UNIT TO REPLACE MOTOR 16 A Follow the steps outlined in DISASSEMBLE UNIT B Remove groundnut and wires from PCB noting wiring C Loosen motor mounting bolts D Slide motor forward and remove from chassis E Install new motor Reattach ground and motor leads Slide motor back and tighten bolts TO REPLACE SPEED POTENTIOMETER A Remove knob and mounting hardware B Slide pot Assembly out of enclosure C Install new pot Assembly in reverse sequence D Verify that when the knob is turned fully counter clockwise the indicator line is at 7 00 TO REPLACE FWD OFF REV SWITCH A Remove switch sealing boot using care to prevent damage to it B Slide switch assembly out of control panel noting which side keyway slot on bushing is facing C Insert switch assembly into control panel with keyway slot in proper direction reinstall boot and tighten until switch
23. istor R 4 feeding it through R 19 and R 20 to level amp U1 B and related components As current through R 4 approaches 2 0 amps for 120 voltunits 1 0 amps for 240 volt units voltage to TP 4 rises to approximately 4 0VDC This is fed through resistor network R 22 and R 23 at a 2 to 1 ratio into the peak detector CR 10 amp C 9 The output of the peak detector is buffered R 24 amp Q 4 by an emitter follower Q 4 amp R 24 amplifier which discharges integrator C 10 retarding the SCR firing angle The resultant firing angle will be proportional to the difference between the torque reference charging current R 18 and the torque feedback discharging current R 25 30 F The SCR will fire when the integrator C 10 voltage is equal to the PUT Q 5 reference voltage CR 7 R 11 amp R 12 Line synchronization is achieved by allowing the reference voltage to drop to zero with each line cross thereby discharging C 10 through Q 5 C 10 amp Q 5 form a relaxation oscillator whose period is proportional to the rate of charge of C 10 When the voltage across C 10 is equal to the reference voltage the PUT Q 5 is forward biased and will conduct discharging C 10 through the base emitter junction of buffer Q 6 R 9 bypasses any leakage current while C 11 filters out noise pulses G The pulse output of the relaxation oscillator C 10 amp Q 5 is buffered and amplified by Q 6 and level shifted by Q 3
24. lacement parts list section The repair procedures section details disassembly and assembly procedures After repair the product should be calibrated and checked for proper performance Please refer to the operators manual pt A 1299 0110 for A APPLICATIONS DATA B PRODUCT DESCRIPTION C INSTALLATION D SETUP E OPERATION F USER CALIBRATION G USER TROUBLESHOOTING amp MAINTENANCE H ACCESSORIES I SPECIFICATIONS 27 SAFETY CONSIDERATIONS Servicing must be performed only by personnel trained and skilled in the methods of troubleshooting and repair of electro mechanical products Use of procedures other than those described in this manual may result in a safety hazard to service personnel and or customers When servicing any component of this unit make absolutely sure that all power to circuitry is removed If any functional checks are to be performed while power is applied and chassis is disassembled care must be exercised for the following A THIS IS A LINE OPERATED DEVICE AND IS NOT ISOLATED FROM GROUND USE OF A ISOLATION TRANSFORMER IS STRONGLY RECOMMENDED B DO NOT INADVERTENTLY SHORT ANY PART OF THE PRINTED CIRCUIT CARD TO GROUND AS SEVERE DAMAGE WILL RESULT C MAKE ABSOLUTELY SURE THAT ANY TEST EQUIPMENT THAT IS USED FOR REPAIR IS NOT REFERENCED TO EARTH GROUND 28 THEORY OF OPERATION The variable speed controller employs a phase controlled rectifier bridge to vary the power applied to a permanent m
25. licable to the above model LISTINGS DESCRIPTION BARNANT Part Speed adjustment knob 7520 900 1273 900 1274 E p 19 After repairs are made the unit must be tested to assure proper performance to specifications In many cases servicing personnel to accomplish this can use factory QC checkout procedures For calibration procedures please refer to the following CAL SPECIFICATION listings table appropriate to the model that is being serviced RABE 77521 40 CAL 1836 71521 47 Additional technical specifications are available in the unit s OPERATOR MANUAL Because this manual is covering approximately 15 different models exact calibration procedures will differ between each unit However the following procedure may be used to roughly tweek an out of spec unit 20 A BEFORE PROCEEDING FURTHER PLEASE NOTE ALL WARNINGS AS LISTED IN THE SAFETY CONSIDERATIONS SECTION 1 Phillips screwdriver B Non metallic pot tweaker C Hand held tachometer 1 Follow procedure for unit dissasembly 2 Plug unit into the appropriate line voltage If this can be done through an adjustable variac to e g 115 vac 115 volt units or 230 vac 230 volt units 3 Turn unit on set speed control for maximum 4 Measure amp turn pot R 90 E 2274 0003 amp 0004 series PC Boards R 33 E 2219 xxxx series both pots are multi turn to obtain proper motor terminal voltage as follows 100 0 v
26. losure start stop control of the drive motor Additional circuitry allows the user to remotely select the front panel or linear input speed references using a contact closure The output of the commanded 4 20 mA and 2 10 VDC inputs are optically isolated from the ac line minimum 1250 Vac for 115Vac units 1900 Vdc for 230Vac units DETAILED CIRCUIT OPERATION 7520 XX SERIES CONTROLLERS GENERAL OVER VIEW A The 7520 series controller board employs modular SMT technology see figure 1 to provide a single board solution employing an SCR based power amplifier to drive permanent magnet motors up to 1 HP Power Supply A AC line is brought in at J 3 and J 4 and routed through FWD OFF REV switch contacts to power bridge consisting of CR1 CR4 B 100 VDC at TP 8 is dropped by series resistor R 26 and regulated to approximately 22 7 VDC at TP 6 by CR 7 C LED DS 1 indicates power ON to circuitry D Varistor VR1 and RC network amp suppress line noise generated externally and internally by motor and power bridge Output Drive A Motor power bridge consists of CR 3 CR 4 Q 1 Q 2 Diode CR 5 bypasses the inductive current surges of the motor when the Power Bridge shuts off The output bridge 1s routed through FWD OFF REV switch contacts to allow motor reversal and is brought out at J 1 and J 2 of the PCB B Resistor capacitor combination consisting of R 5 and C 2 forms a snu
27. n is permitted without the permission of BARNANT Barnant Company Division of Cole Parmer Instrument Company Inc 625 East Bunker Court Vernon Hills Illinois 60061 1844 847 549 7600 847 247 2929 Fax 800 323 4340 A 1299 0442 Edition 04 25 TABLE OF CONTENTS SAFETY CONSIDERATIONS PAGE 4 THEORY OF OPERATION PAGE 5 DETAILED CIRCUIT OPERATION PAGE 6 7 TROUBLESHOOTING sees PAGE 8 REPAIR PROCEDURES PAGE 9 REPLACEMENT PARTS LISTING PAGE 10 CALIBRATION PROCEDURE PAGE 11 12 FUNCTIONAL TEST PAGE 13 FUNCTIONAL SPECIFICATIONS PAGE 14 26 INTRODUCTION Service for this product is performed at three levels the customer distributor COLE PARMER and factory depot repair This manual describes distributor COLE PARMER service procedures Customer service procedures are described in the operators manual Customers are encouraged to perform service as described in the operators manual as well as in special circumstances where special skills and safety are not considerations To use this manual begin with the troubleshooting section to isolate the fault to a replaceable part The functional description and check out procedure sections are also helpful in determining the faulty part Distributor COLE PARMER repair is limited to replacement of modules as detailed in the rep
28. ofthe above circuits have to start at zero and then span This is accomplished by setting U4 A for an offset of 1 volt The resultisa 0 4 volt control signal H D13 is configured as an adjustable zener diode This will conduct at 6 volts to clamp off U3 A outputs of greater than 5 volts preventing excessive drive speed 10 e ORI eT d 4 gt 1 di ale T MEE i3 RIS 1 S UL na y RIB M E 2219 20 30 s 5n 60 ET Tr T iz d 7 motu DELATI T PS wa pm E Esel 9 Figure 2 Typical controller board employed in the 77521 series drives 11 25 0kS s 789 Acqs EE dA 120 H2 1 66 Hz chi RMS 116 6 V Ch2 Mean 32 1V Ch4 Mean 1 84mVv Ch4 RMS 5 80mv 86 3 Sep 1996 09 38 29 Waveform 1 Test point 6 Follow for operation Waveform 2 Output of scr bridge across motor Waveform 3 PUT charging ramp test point 5 Waveform 4 Motor current measured using zz TPC 202 current probe 12 Repairs on this unit are basically confined to either the unit s control PCB and or the drive motor assembly Where possible swap known good parts to localize and isolate the problem The following is a list of possible problems and remedies UNIT DOES NOT TURN ON NO POWER LIGHT 1 Fuse blown replac
29. ut causes the drive to run while a continuous active low to the Remote Local input switches speed control to the front panel speed control Input Voltage Input Current High State 15 VDC Typ 100 uA Max leakage Low State 0 8 VDC Max 1 5 mA Max All inputs will be electrically isolated from the ac line minimum 1250 Vac for 115Vac units 1900 for 230Vac units 23 4 3 3 Remote Analog Input Ref ISA S50 1 4 20 mA Input 250 ohms typical input impedance referenced to signal ground 4 mA Stop 20 mA Full Speed Accuracy 396 F S Linear Resolution Overload Capability 10 V or 40 mA max 2 10 V Input 10 K ohms typical input impedance referenced to signal ground 2 V Stop 10 V Full Speed Accuracy 396 F S Linear Resolution Overload Capability 15 V max Only one of the analog inputs may be used at any one time The front end ofthe circuit is a differential op amp to allow for multiple units max 3 to be cascaded in series Current Input or parallel Voltage Input for control Both 4 20 mA and 2 10 VDC inputs are optically isolated from the ac line minimum 1250 Vac for 115Vac units 1900 Vdc for 230Vac units 4 4 ENVIRONMENTAL INPUTS ref DSM 8806 Indoor Use Nonmobile laboratory or office environment readily accessible to maintenance Normally only non conductive pollution occurs but a temporary conductivity caused by condensation must occasionally be expected IEC 664 Pollution Degree 2 Minimum Maximum
30. will not rotate TO REASSEMBLE UNIT PROCEED AS FOLLOWS A Carefully plug all connectors into PCB observing proper orientation of plugs 17 The following is a list of stockable motor assemblies main control PCB assemblies and their reference schematic diagrams for all indicated models MODELS MODEL MAX Motor Assembly PCB REFERENCE SCHEMATIC 7520 40 600RPM 115V 5870 0021 CR E 2219 0006 CR E 2193 7520 50 100RPM 115 5871 0007 CR E 2219 0006 CR E 2193 7520 60 300RPM 115 5870 0021 CR E 2219 0008 CR E 2193 7520 47 600 230 5870 0012 CR 2219 0007 2193 7520 57 100 230 5871 0008 2219 0007 2193 7520 67 300RPM 230 5870 0012 2219 0009 2193 900 1076 600RPM 115V 5870 0021 2219 0006 2193 900 1077 600RPM 230V 5870 0012 2219 0009 2193 900 1268 600RPM 115V 5870 0013 2219 0008 2193 900 1273 600RPM 115V 5870 0021 2219 0006 2193 900 1274 600RPM 230V 5870 0012 2219 0007 2193 77521 40 600RPM 115V 5870 0021 2274 0003 2268 77521 50 100RPM 115V 5871 0007 2274 0003 2268 77521 47 600RPM 230 5870 0012 2274 0004 2268 77521 57 100RPM 230 5871 0008 2274 0004 2268 18 The following is a list of commonly used parts app
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