1235 USER MANUAL - SCR Controls Inc.
Contents
1. BEL HR 20 Basic Drive Operator Control Interconnections 21 AG DG Relays e d ne au d L meae ge ee quus 23 Operator s Speed Adjustment aaaaaaaaaaaaasaaananananannnannnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnannnannnanaaa 26 Temporary Jumper Gate to Anode aaaaaaasaaasaaasaaasaansannnaannsnnnnnansnnnnnannnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnna 28 TABLE OF TROUBLE SHOOTING CHARTS TROUBLESHOOTING CHART 1 DRIVE FAILS TO 5 30 TROUBLESHOOTING CHART 2 DRIVE SPEED UNSTABLE eene 31 TROUBLESHOOTING CHART 3 SPEED REGULATION NOT WITHIN SPECIFIED LIMITS 31 TROUBLESHOOTING CHART 4 MAXIMUM SPEED POT NOT ABLE TO CAUSE TOP SPEED OF DRIVE 31 TROUBLESHOOTING CHART 5 DRIVE RUNS TO FULL SPEED NOT UNDER CONTROL 32 TROUBLESHOOTING CHART 6 MAX SPEED POT NOT CAPABLE OF SETTING SPEED LOW ENOUGH 33 TROUBLESHOOTING CHART 7 JOG OPTION WILL NOT JOG RUNS 33 TROUBLESHOOTING CHART 8 POWER 34 TROUBLESHOOTING CHART 9 RUN RELAY 35 TROUBLESHOOTING CHART 10 SPEED REFERENCE 36 TROUBLESHOOTING CHART 11 ERROR AMPLIFIER amp FEEDBACK CIRCUIT 37 TROUBLESHOOTI2. TB 1 2 C1 C2 L1 L2 2 3 4 5 13 10 Lu s alo C 4 CLUTCH 415 VAC START STOP COIL D C TACH IF USED SPEED POT CUSTOMER AUXILIARY CONTACT ON MOTOR STARTER Figure 14 Basic Drive Operator Control Interconnections 21 6 5 ALLOWABLE AMPACITIES OF INSULATED COPPER CONDUCTORS Not more than 3 conductors in raceway or cable or direct burial based on ambient temperature of 30 C 86 F Size Temperature Rating of Conductor AWG 60 C 75 C 85 C 90 C 110 C 125 C 200 C 250 C MCM 140 F 167 F 185 F 194 F 230 F 257 F 392 F 482 F Types Types Types Types Types Types Types Types RUW RH V TA AVA A1 A TFE 14 2 RHW M1 TBS AVL 14 8 14 8 Nickel T RUH SA AA AA or TW 14 2 AVB FEP FEP nickel THW 515 FEPB coated THWN FEP copper XHHW FEPB only RHH XHHW THWN 14 15 15 25 30 30 30 30 40 12 20 20 30 30 35 40 40 55 10 30 30 40 40 45 50 55 75 8 40 45 50 50 60 65 70 95 6 55 65 70 70 80 85 95 120 4 70 85 90 90 105 115 120 145 80 100 105 105 120 130 145 170 752 95 115 120 120 135 145 165 195 ird 110 130 140 140 160 170 190 220 20 125 150 155 155 190 200 225 250 00 145 175 185 185 215 230 250 280 000 165 200 210 210 245 265 285 315 0000 195 230 235 235 275 310 340 370 250 215 255 270 270 315 335 300 240 285 300 300 345 380 350 260 310 325 325 390 420 400 280 335 360
3. rele 19 5 9 FRICTION BRAKE OPTION BOARD etti i o SO REG RC HR RR lH eI EUER GE 20 SECTION 6 INS TABLA TION Et 21 6 1 DESIGN a ee tee Melt Leia ia Siti 21 6 2 CRITICAL ENVIRONMENTAL 5 21 6 3 SHIELDED CABLE bec UE deme i o eq ctl een be m cete ed 21 6 4 EXTERNAL AG RELAYS unici eU ECHO ADI RR IR 21 6 5 ALLOWABLE AMPACITIES OF INSULATED COPPER 22 6 6 TRANSEORMERS ea nn REC a D ee a 23 6 7 CLUTCH GIRGCUIT oem tette ba alan ee ed 25 SECTION 7 START UP INSTRUCTIONS 2 sbn 22 2 Pe aan an el 26 7 1 GENERAL START UP PROCEDURE cu u ate bieten ee rq tp ute duet tede tte 26 7 2 SAFETY PREGAUTION 5 Renee eati oU DEM cien cR 26 7 3 PRELIMINARY TESTS ceca n es tete pen ee ee es 26 7 4 BASIC CONTROL SET UP er pente eee eh 27 7 5 EDDY GURRENT ADJUSTMENT tiat ctt cei te itta ere eate eisen 27 SECTION 8 TROUBLESHOOTING 24 55 22 22 a neue 28 8 1 TROUBLE SHOOTING PROGEDURE n nene BER eee guis 28 8 2 TEST METER ml uec ete be ed ree e WEN ed e rne tene 28 8 3 OSCILLOSCOPE SIGNAL TEST et tte ee d eR ent RER 28 8 4 COMPONENT TESTING rhet ala na a a Dana 29 SECTION G
4. 3 REFERENCE SHUT OFF INPUT POWER CHECK FUSE 1FU CHECK WIRES TO A AND S ON BOARD FROM BLOCK AND FUSE SHUT OFF POWER THERE IS APPARENTLY A SHORT ON THE 15V LINE POSSIBLE CAUSES DZ2 DEFECTIVE C17 CAPACITOR DEFECTIVE Q1 OR Q2 TRANSISTOR DEFECTIVE L1 OPERATIONAL AMPLIFIER DEFECTIVE TRACES SHORTED DUE TO FOREIGN MATTER ON TRACES OR BETWEEN PARTS ON BOARD aeons CHECK METHODS OF CHECKING COMPONENTS WITH OHMMETER APPLY POWER 115VAC TO TB 1 L1 amp L2 K1 DE ENERGIZED NO RUN OR JOG NO EXTERNAL LOADS ON DC SUPPLIES METER AC VOLTS RANGE 130VAC SUPPLY METER DC VOLTS METER LEADS TO PIN A METER LEADS AND PIN S ON MAIN 3 RANGE 30VDC BOARD READ NEG LEAD TB 1 15 APPLIED HEADS BERLIN POS LEAD PINE VOLTAGE LEADS ON T2 TERM 3 TO TERM 9 READS REFER TO MANUAL SECTIONS 1 OPERATION AND FUNCTIONAL DESCRIPTION HOW TO USE A MULTIMETER CHECKING COMPONENTS WITH AN OHMMETER SCHEMATIC 12351 METER A C VOLTS RANGE 50VAC SHUT OFF POWER TRANSFORMER T2 DEFECTIVE REPLACE WITH PC 40 250 30VOLTS SHUT OFF POWER BRIDGE RECTIFIER 30VDC POS LEAD TB 1 15 NEG LEAD PIN Y READS 30V CATHODE D 1 READS 20V D1 OPEN REPLACE WITH GOOD E1 DIODE IS R3 590 OHMS 2 RESISTOR GE
5. NG MOVE BLACK METI READS MOVE BLACK METI READS 5 VOLTS LEAD TO THE EMITTER OF Q3 OR R8 5 6 VOLTS LEAD TO THE EMITTER OF Q4 OR PINH ama POWER 115VAC TO Nai 12 POWER SUPPLIES OK YES PRESS RUN BUTTON RELAYS K1 amp K2 ENERGIZE YES METER DC VOLTS RANGE 30VDC POS LEAD TB 1 15 NEG LEAD TB 1 6 READS 10 VOLTS 10V 10 BLACK METER LEAD TO TB 1 7 OBSERVE ZERO TO 10 VOLTS 02 FULLY ccw ROTATE EXTERNAL SPEED POT TROUBLESHOOT RANGE AND METER VARIES FROM NOTE MIN SPEED POT REFER TO POWER SUPPLY TROUBLE SHOOTING GUIDE REFER TO RUN NO RELAY CIRCUIT gt TROUBLE SHOOTING GUIDE REFER TO POWER SUPPLY TROUBLESHOOTING GUIDE 10V REFERENCE SUPPLY 50 VOLTS AT TB 1 7 ADJUST SPEED POT FOR OF D3 READS 4 4V OF D3 READS 5V MOVE BLACK METER LEAD TO THE CATHODE MOVE BLACK METER LEAD TO THE CATHODE N _ SHUT OF POWER CHECK Q2 REFER TO MANUAL SECTIONS 1 OPERATION amp FUNCTIONAL DESCRIPTION 2 HOW TO USE A MULTIMETER 3 CHECKING COMPONENTS WITH AN OHMMETER 4 SCHEMATIC 12351 mP OF Q1 OR 5 MOVE BLACK METER LEAD TO THE EMITTER READS 15 6 VOLTS INCREASE THE SPEED POT FULL CLOCKWISE WHILE Q8 SERVING THE METER THE VOLTAGE SHOULD RAMP TO THE NEW SP
6. REF CIRCUITRY Y SEE TROUBLE SHOOTING INSTR ERROR AMP w SEE TROUBLE SHOOTING INSTR AND SCR OUTPUT STARTAC MOTOR START CHECK TO INSURE WIRING IS TO CONNECTION DWGS MOST PROBABLE CAUSE A POWER NOT APPLIED TO CONTROL B AC MOTOR OFF C WIRING WRONG ARE CONNS OK CONNECT PER PRINT ISAC MOTOR STARTED Y REPEAT START OF INSTRUCTIONS CHECK TO SEE THAT H amp 1 PINS ARE CONNECTED TO JOG BOARD CHECK TO SEE THAT JOG RELAY IS NOT ENERGIZED CHECK LOAD MECHANICALLY CHECK TO SEE THAT JOG P8 IS WIRED TO PRINT AND THAT WHEN REPLACE FUSE IS FUSE BLOWN q YE RUN P8 IS PUSHED DOES K2 CONN Y NO FUSE REPLACED Y SEE TROUBLE WITH K2ACTUATED TURN UP SPED POT Ye ROTATION SEE DCVM INSTRUCTIONS MEASURE C C AND RECORD IS 80 TO 100 VDC PRESENT TURN OFF POWER CHECK CONNS TO SHOOTING K1 OR K2 DO NOT ACTUATE CLUTCH AT CONTROL C1 AND C2 AND AT DRIVE NO CONNECT CLUTCH PER SCHEMATIC YES WITH POWER OFF OPEN BOTH LEADS AT CONTROL TO CLUTCH SEE OMMETER INSTR CHECK RESISTANCE NORMALLY OPEN OF WIRES PLUS JOG P8 IS IN CIRCUIT CLUTCH CAUTION DO NOT no SEE ALLOW CLUTCH ne start 4
7. RUN TO JOG PUSH BUTTON IF USED 115VAC A 11 AMPLIFIER RATE CIRCUITS CLAMP RELAYS Figure 4 Run Relay Circuit 5 2 RUN RELAY CIRCUIT 5 2 1 OPERATION The auxiliary contact of the AC motor starter is connected from terminal 2 to 5 on terminal board 1 This prevents over regeneration of the clutch coil If the control should be started without the AC motor running If a drive over temperature switch is used connect in series with auxiliary contact as shown Other remote normally closed stop push buttons may be in series with stop push button PB if desired Start when run PB is pushed 115VAC is applied to relay K1 through auxiliary of motor starter stop normally closed PB contact run PB normally open contact When run PB is released relay K1 normally open contact 9 5 which closed across run normally open PB maintains K1 relay energized Relay K1 normally open contact 10 6 connects relays K2 K3 and K4 across 30VDC through diode D2 Relay K1 applies AC to the power bridge See SCR Power Output Control Circuit Relays K3 and K4 open their normally closed contacts which unclamp the amplifier dynamic compensation capacitors K1 contact 9 5 also applies 30V to the speed reference circuit See description of Speed Reference Circuit When auxiliary contact of starter opens or stop push button is pushed 115VAC is removed form relay K1 K2 K3 and K4 drop out and the AC is removed from
8. DOWN AS POT IS TURNED PROBLEM PERSIST TURN MIN SPEED BIAS AND OPERATOR SPEED POTS FULLY C C W PUSH RUN P 8 DOES DOES DRIVE ACCELERATE TO HIGH SPEED AS RUN P 8 PUSHED YES MOST PROBABLE CAUSE 1 TACH MISWIRED CHECK WIRING TO OPERATOR SPEED PRINT C W AND C C W WIRES REVERSED POT amp CORRECT PER Y Y gt lt WITH RUN P 8 PUSHED amp MIN v SPEED BIAS amp OPERATOR SPEED POTS C C W TURN SPEED POT SEE TROUBLE SLOWLY TO FULL C W SHOOTING INST POWER SUPPLY IF JOG OPTION OS USED CHECK TO SEE IF DOES DRIVE JOG RELAY IS ENERGIZED JOG RELAY RUN TO FULL SPEED AS SPEED OPT I TURNED gt SHOULD BE DE ENERGIZED CHECK WIRING v OF JOG CONNECTION IS JOG P 8 A SLIGHTLY CW NORMALLY OPEN P 8 SEE TROUBLE SHOOTING INST PHASE CONTROL amp SCR OUTPUT PUSH STOP TURN OFF POWER CHECK WIRING TO TACH IF INCORRECT CONNECT PER PRINT Y SEE TROUBLE SHOOTING INST ERROR READ START UP INSTRUCTIONS amp CHECK TACH POLARITY INSTRUCTIONS SET UP DRIVE PER SEE MULTIMETER OPERATING INSTRUCTIONS A C MEASUREMENT PLACE A C V M ON TR2 13 amp 14 START DRIVE CAUSE DRIVE TO TURN TO FULL SPEED BY TURNING UP SPEED POT IS FULLY C W v S ARM VOLTAGE MEASURED TURN OFF POWE
9. Eddy Current Model HP Range VAC 1235 1 3 4 150 115 1235 45 150 900 115 INPUT TOLERANCE Line voltage variations should not exceed 5 to 10 Frequency limitations 60HZ 2HZ ALTITUDE Up to 3300 feet Consult factory for higher elevations AMBIENT TEMPERATURE 10 C 40 C PERFORMANCE CHARACTERISTICS Linear Acceleration 2 30 seconds Extended time optionally available SPEED REGULATION Internal AC Tachometer 2 of top speed DC Tachometer 5PY 1 regulation w 95 load change 1 drift 42 12 regulation w 95 load change 1 drift BC46 1 regulation w 95 load change DIGITAL REGULATION 05 of set speed over 10 to 1 speed range 3 1 SCHEMATICS 1235 1 Eddy Current Control 1235 45 Eddy Current Control High Power 1235 6 Brake Option 1235 7 Jog 1235 15 Dancer Feedback 1235 18 Threshold Detector 1235 19 Accel Mechanical Drives ED 80 160 ED 320 640 1280 4500 SECTION 3 DESCRIPTION The 1235 1 Eddy Current Speed Control Printed Circuit Board Contains the following circuitry Power supply Run relay Speed reference Speed feedback Error amplifier Phase control SCR power output Jog option board Friction brake option board 3 2 ADJUSTMENTS P1 Accel P2 Min Speed P3 Max Speed P4 Meter Calibration P5 Stability P6 Lead P7 Gain P8 Bias SECTION 4 THEORY OF OPERATION 41 DRIVE OPERATION An Eddy Current drive system consists of AC Motor and Eddy C
10. IF IT IS NOT POSSIBLE TO ELIMINATE HUNTING WITH STABILITY ADJUSTMENT REDUCE GAIN ADJUSTMENT SETTING 12 Press STOP push button 13 Press RUN push button Note length of time it takes drive to reach run speed Press STOP push button Increase ACCEL RATE adjustment setting to achieve desired acceleration rate Acceleration time is adjustable from 2 to 30 seconds Zero setting corresponds to approximately a 30 second acceleration time 10096 setting corresponds to approximately a 2 second acceleration time Repeat procedure as necessary to obtain desired acceleration rate 14 Press AC MOTOR STOP push button Set up is complete 27 SECTION 8 TROUBLESHOOTING 81 TROUBLE SHOOTING PROCEDURE Common causes of drive malfunction after satisfactory operation are e Broken or loose interconnecting wires e Faulty insulation or interconnecting wires e Component failure A close visual inspection with ALL AC POWER OFF can save hours of needless troubleshooting Component failure is often located by discoloring or ruptured appearance 82 TEST METER Check across each circuit element e g wires contacts relays push buttons etc for continuity 8 3 OSCILLOSCOPE SIGNAL TEST WARNING WHEN A TEST INSTRUMENT IS USED CARE MUST BE TAKEN TO INSURE THAT ITS CHASSIS IS NOT GROUNDED EITHER BY GROUNDING PLUG CONNECTION OR BY ITS CASE BEING IN CONTACT WITH A GROUNDED SURFACE A multi meter is the most
11. risk of loss for goods not at Melltronics factory and any cost required to remove or prepare the goods for shipment to the repair facility and to reinstall equipment subsequent to repair This warranty is effective only if written notification of any claim under this warranty is received by Melltronics at the address indicated below within thirty days 30 from recognition of defect by Buyer The above indicates the full extent of Melltronics liability under this warranty Melltronics specifically disclaims any liability for a damage or failure due to improper use or installation b damages in shipment c damage or failure due to abnormal operation conditions of load temperature altitude or atmosphere whether intentional or unintentional d non authorized service repair modification inspection removal transportation or installation e misapplication or misuse or f consequential damages arising out of the use operation or maintenance of the goods THERE ARE NO OTHER WARRANTIES EXPRESSED OR IMPLIED WHICH EXTEND BEYOND THAT DESCRIBED HEREIN MELLTRONICS SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTY OF MERCHANTABILITY OF GOODS OR OF THE FITNESS OF THE GOODS FOR ANY PURPOSE Melltronics neither assumes nor authorizes any representative or any other person to assume for Melltronics any other liability in connection with the sale or any shipment of Melltronics goods Melltronics reserves the right to make changes and improvements in
12. the power bridge The capacitors in the amplifier circuit are discharged The ramp capacitor C4 is discharged and the reference voltage is removed from the speed pot If the Jog option is used the normally open jog pushbutton is connected from 9 of the control terminal strip 1 to 1 on the jog option board The jog push button receives no power at customer connection pin number 9 unless 1 Starter is closed 2 Stop Push button not depressed 3 Thermal switch if used closed and 4 f the run circuit K1 is not latched See Jog Option description The relays K2 K3 and K4 are energized through terminal G which is connected to the jog option board See Jog Option description 12 TO ERROR AMPLIFIER L1 INPUT OR JOG OPTION BOARD Figure 5 Speed Reference Circuit 5 3 SPEED REFERENCE CIRCUIT 5 3 1 OPERATION With relay K1 de energized normally open contact 10 6 open normally closed contact 11 3 closed speed pot fully clockwise A Approximately Zero B Approximately plus 0 5V C Approximately Zero 0 D Approximately Minus 0 5V E Approximately Zero 0 With relay K1 energized A Minus 10V 5 B Approximately voltage at A Minus 0 5 V or approximately minus 9 5V C Ramping to approximately same as A D Ramping to approximately same as C plus 0 5V or minus 10 5V E Ramping to approximately same as A 5 3 2 FUNCTIONAL DESCRIPTION OF OPERATION With K1
13. 2 2 2 ae Q h S a E 39 SECTION 10 REVISION HISTORY uu it an le nennen 40 SECTION f WARRANTY uu a au Va as Ba aa Eaa 43 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 TABLE OF FIGURES Eddy Current Drive Schematic aaaaaaaaaaaaaaasaaasanasnnasnnannnannnnsnnnnnnnnnnannnannnannanannnananananansaananansaansaanaaanaa 8 1235 Eddy Current Control Basic Block 9 Power Supply Circuit aaaaaaasaaasaansannsannsnnnnnannnnnnnnnnnnnnnnunanunnnunnnnnnnnunnnunnnnnnnnnnnnnnnnunnnnnnnnnnnnnnnnnnnninnnnnnni 11 Relay 22 12 Speed Reference nenne entren tenis adasia ia Dia stad nina adaa 13 Speed Feedba kK 14 Error Miei EC 15 Phase Gohtrol s tua a a uqta aki 16 Power Output CIRCUIT u een et 17 Bridge and Coil Current Conduction 11 12 18 Bridge and Coil Current Conduction 11 12 18 Jog Option BOard u utr Bie en dude nn ILL 19 Friction Brake Option a t dad
14. AMPLIFIER DC COMMON At this level a small reference input will fire the SCR s and hesitation with long range inputs is eliminated Relays K3 and K4 normally closed contacts remove the charge from the capacitors used to obtain dynamic compensation Relays K3 and K4 de energize when the line contactor K2 opens See Line Contactor Circuit description 15V T1 PULSE gt TRANSFORMER Figure 8 Phase Control Circuit 5 6 PHASE CONTROL CIRCUIT 5 6 1 OPERATION Transistor Q5 operates to discharge the timing capacitor each time the AC line goes through zero When the line is not near zero the negative unfiltered full wave DC voltage reverse biases the base emitter junction of Q5 Q5 turns off and C13 is able to charge When the AC line crosses zero the negative voltage becomes zero Transistor Q5 becomes forward biased with the base current supplied by the 15V supply through R26 Each time the line crosses zero Q5 turns on to discharge C13 Capacitor C12 provides a shunt path for noise which may cause false firing of Q5 Diode D11 conducts when Q5 base emitter junction is reverse biased This prevents breakdown conduction of the B E junction After each line crossing C13 is able to charge from the 15V regulated supply through R14 Unijunction Transistor Q6 provides a means of providing an SCR trigger as a function of the time after line crossing On a 60HZ line a timing period begins every 8 3
15. EXITATION OVER 75V CHEE SFO SRI FOR PROLONGED PERIOD IS CLUTCH CURRENT OPEN q o PEN RECONNECT CLUTCH PLACE CLAMP ON AMP METER ON AC LINE ON MOTOR APPLY DC NETWORK TO C1 AND C2 Y ono TURN ON POWER START AC MOTOR PUSH RUN P8 AND TURN UP SPEED POT 1 2 ROTATION READ AC AMPS IN MOTOR AND RECORD DOES CURRENT RISE TO AT LEAST FULL LOAD CONSULT MELLTRONICS SERVICE DEPT HAVE INFORMATION AVAILABLE 1 COIL RESISTANCE MEASURED AT DRIVE AND MAX CLUTCH VOLTAGE MEASURED AT C1 AND C2 TOTAL RESISTANCE OF COIL PLUS WIRES WHEN MEASURED PREVIOUSLY HP AND FL AMPS FROM AC MOTOR INFO ON DRIVE NAMEPLATE ORDER NUMBER AND OR MELLTRONICS JOB NUMBER IF KNOWN N ano FlowChartDrive FailsToStartvsd 9 27 2007 MELLTRONICS TROUBLESHOOTING CHART 1 DRIVE FAILS TO START 30 START gt OBSERVE DRIVE SPEED CAREFULLY DOES THE DRIVE WANDER SLOWLY ABOUT SPEED IN A RANDOM PATTERN OR DOES THE DRIVE SPEED MAKE A CYCLIC OSCILLATION RANDOM IF THE FEEDBACK TACH IS NOT THE AC TACH INTERNAL TO THE DRIVE CHECK TO SEE THAT THE COUPLING FROM THE DRIVE TO THE TACH IS FREE OF BACKLASH v Y CHECK CONNECTIONS TO CONTROL SEE PERFORMANCE OPTIMIZATION ADJUSTMENTS ESPECIALLY TACH CONNECTIONS amp SPEED POT CONNECTIONS o CHECK SHIELDING PEN I
16. JOG P B IS DEPRESSED CHECK EXTERNAL WIRING TO JOG P B NO YES SEE MULTIMETER INSTRUCTION NO D C VOLTAGE MEASUREMENT Va PLACE BLACK LEAD TO TB 4 3 OF E JOG OPTION BOARD PLACE RED LEAD ON TB 4 2 PUSH JOG P B YES PLACE A C V M ACROSS N O TERMS OF vi IS A D C VOLTAGE EASURED VOLTAGE SHOULD BE OBSERVED WITH P B RELEASED VOLTAGE SHOULD REDUCE TO ZERO WHEN IS RELAY JA ON JOG OPTION P B IS DEPRESSED IF VOLTAGE BOARD 1235 7 OPERATING WHEN READ DOES NOT REDUCE TO JOGPBJSDEPHESSED ZERO P B CONTACT IS NOT YES NO CLOSING CHECK RELAY WITH METER LEAD CONNECTED COIL TO TB 4 2 CHECK FOR 15VDC AT F RESISTANCE ON JOG OPTION BOARD DV 15V CHECK FOR BROKEN S LEAD REPLACE TO MAIN BOARD BROKEN RELAY TRACES TO RELAY SOCKET RETEST JOG CHECK FOR VOLTAGE AT ON OR BAD CONTACTS IN RELAY MAIN BOARD WITH LEAD TB 4 OR SOCKET 2 LEAD AT 1 JOG JOG POT MAX C W NO VOLTAGE RECHECK OPTION WIRING FOR gt CALL MELLTRONICS BROKEN LEADS TO FIELD SERVICE MAIN BOARD FlowGhartlogOgtionTroublashoetin illNotJogRunsOK vs 9 27 2007 SCR o A A MELLTRONICS CONTROLS INC JUSTRIAL INC TROUBLESHOOTING CHART 7 JOG OPTION WILL NOT JOG RUNS 33 SYMPTOMS 1 DRIVE FAILS TO RUN 2 NODC SUPPLY
17. USE A MULTIMETER CHECKING COMPONENTS SYMPTOMS 1 K1 FAILS TO ENERGIZE LATCH 2 K2FAILS TO ENERGIZE APPLY POWER TO 1 11 METER SURELY WITH AN OHMMETER AC VOLTS RANGE 130VAC TROUBLE 4 SCHEMATIC 12351 LEADS BETWEEN TB 1 1 2 SHOOTING READS APPLIED GUIDE AC VOLTAGE 150VAC SHUT OFF POWER TO BOARD CHECK EXTERNAL WIRING TO AUX CONTACT ON AC MOTOR STARTER CHECK THIS CONTACT FOR CLOSURE CONNECT OHMMETER BETWEEN TB 1 2 amp TB 1 5 SHOULD READ LESS THAN 5 OHMS PROBLEM CORRECTED MOVE ONE METER EAD FROM TB 1 2 TO 1 5 READS APPLIED AC VOLTAGE 115VAC MOVE ONE METER LEAD FROM TB 1 5 TO TB 1 4 READS APPLIED AC VOLTAGE 115VAC SHUT OFF POWER CHECK EXTERNAL STOP CIRCUIT WIRING AND STOP SWITCH OHMMETER CHECK STOP CIRCUIT AND CORRECT PROBLEM PROBLEM CORRECTED MOVE ONE METER LEAD FROM TB 1 4 TO TB 1 3 PRESS RUN BUTTON READS APPLIED AC VOLTAGE 115VAC SHUT OFF POWER CHECK EXTERNAL RUN CIRCUIT WIRING AND RUN SWITCH OHMMETER CHECK RUN CIRCUIT AND CORRECT PROBLEM PROBLEM CORRECTED DEPRESS RUN BUTTON AGAIN HAS K1 RELAY PICKED UP CAN BE CHECKED BY PLACING OHMMETER LEADS BETWEEN PIN B AND PIN Z RELEASE RUN BUTTON METER CONTINUES TO READ APPLIED AC REMOVE RELAY CHECK WITH METER FOR AC VOLTAGE AT TERM 13 amp 14 O
18. common test instrument used in troubleshooting Multi meters having a sensitivity of 1 000 Ohms volt on AC scale and 10 000 Ohms volt on the DC scale are recommended CAUTION NEVER USE A MEGGER BUZZER OR BELLRINGER TO CHECK CONTROL ON NON CURRENT LIMITED CONTINUITY CHECKS OR ASSOCIATED CIRCUITS THE MEGGER BUZZER OR BELLRINGER S HIGH VOLTAGE WILL CAUSE ELECTRONIC COMPONENT DAMAGE 8 2 1 VOLTAGE TEST Voltage checks at critical points are measured using the test meter provided in each system Turn selection switch to each position Refer to START UP INSTRUCTIONS for correct readings 8 22 CONTINUITY TEST When an incorrect voltage is located with the test meter or multi meter DE ENERGIZE ALL AC POWER TO CONTROL The cause may be incorrect resistance in the problem circuit A multi meter set on R x 1 scale will be used to measure the interconnecting wiring which should read less than 2 Ohms 28 WARNING EXTREME CARE MUST BE TAKEN WHEN USING THE OSCILLOSCOPE SINCE ITS CHASSIS WILL BE ELECTRICALLY HOT TO EARTH GROUND WHEN CONNECTED TO THE CONTROL SYSTEM ELECTRICALLY FLOAT OSCILLOSCOPE ABOVE EARTH GROUND 8 3 1 SCR TEST An oscilloscope is the only test instrument that can accurately check gate pulses Refer to NORMAL CONTROL SIGNALS for input and output However the following resistance test will measure for an open or failure in the gate 1 Disconnect SCR module from control and test SCR w
19. except that C2 charges through diode D1 At the anode of D1 an unfiltered DC voltage appears This voltage is used to synchronize the phase control circuit with the AC line crossing Regulated 15 volt supply zener diode and resistor and capacitor C16 compose the supply The zener diode DZ1 is a 15V 5 unit Current for the load and zener is supplied from the 30V unregulated supply through R2 Capacitor C16 provides additional smoothing of the regulated supply and provides a low impedance bypass of the supply Regulated 15VDC volt supply zener diode and resistor and capacitor C17 compose the supply The zener diode DZ2 is a 15V 5 unit Current for the load and zener is supplied from the 30V unregulated supply through R3 Capacitor C17 provides additional smoothing of the regulated supply and provides a low impedance bypass of the supply Varistor provides the power supply and its load with protection form over voltage and from high voltage short duration spikes which are common in industrial environments RC1 provides a low impedance shunt path for fast rising noise and high voltage spikes 10 VARISTOR 115VAC M 15V 30 V 120VAC 1 2 T2 15V F D1 30V E2 573 E C Y I 1 C2 SYNC SIGNAL j 15V z L OMMON 15V J REGULATED TO PHASE CONTROL CIRCUIT Figure 3 Power Supply Circuit 11 CUSTOMER AUX CONTACT ON MOTOR STARTER MOTOR THERMAL IF USED STOP
20. milliseconds If the capacitor C13 reaches the trigger voltage of the unijunction C13 will discharge through the primary of T1 and the SCR s will be fired 16 The charging rate of C13 is controlled by the output of the error amplifier When the input is negative or low positive C13 does not receive enough current to charge it to the trigger level in 8 3 milliseconds The charging current normally through R14 and R13 in series with R24 is diverted through zener 024 TB1 115 VAC CLUTCH As the DC input rises further positive C13 will charge at a faster rate and will reach the trigger voltage of the unijunction before 8 3 milliseconds have elapsed When this happens the SCR which is forward biased at that time will be fired ECTIFIER Figure 9 Power Output Circuit 5 7 OUTPUT CONTROL 5 7 1 OPERATION With K2 contact closed 115VAC is applied to the full wave SCR bridge With pulses applied to the SCR gates See Figure 8 DC is applied to the clutch coil A pulse transformer isolates the SCR output circuit from the rest of the control 172 Conduction from the line through the bridge and clutch coil when L1 is positive relative to L2 is illustrated in Figure 10 2 CLUTCH Figure 10 Bridge Coil Current Conduction L1 L2 Conduction from the AC line through the bridge and clutch coil when L2 is positive relative to L1 is illustrated in Figure 11 Resistor R1 provid
21. panel with single printed circuit board construction 3 Net flexibility many modular modifications possible with simple terminal connection installation 4 Encapsulated SCR power cube provides reliability and simplicity 5 Integrated circuit operational amplifier for high gain fast response 6 Adjustable linear acceleration rate from 2 to 20 seconds supplied as standard 7 296 regulation from standard AC tachometer feedback 22 STANDARD SAFETY FEATURES 1 Mov line transient SCR protection 2 RC SCR Protection 3 Isolated reference circuitry except in torque mode 4 Fused AC Overload Protection 5 Isolated Control Circuitry 2 3 STANDARD ADJUSTMENTS P1 Accel P2 Min Speed P3 Max Speed P4 Meter Calibration P5 Stability P6 Lead P7 Gain P8 Bias 2 4 AVAILABLE OPTIONS The standard drive may be easily modified with simple terminal connection installation Options Include Jog at independent adjustable jog speed Brake power supply Threading at present level Test meter e Follower operation capable of following tachometer generator or external voltage signal reference at an adjustable ratio Current limit AC motor current Torque control regulation Zero speed detector Auto manual selection Phase limit Dancer position Dancer trim Adjustable acceleration deceleration Differential speed trip Operations may be incorporated in combinations to suit applications 2 5 SPECIFICATIONS
22. 360 420 450 500 320 380 405 405 470 500 600 355 420 455 455 525 545 700 385 460 490 490 560 600 750 400 475 500 500 580 620 800 410 490 515 515 600 640 900 435 520 535 555 1000 455 545 585 585 680 730 1250 495 590 645 645 1500 520 625 700 700 785 1700 545 650 735 735 2000 560 665 775 775 840 WARNING NO TERMINAL POINT IN THE CONTROL SHOULD BE EARTH GROUNDED EXCEPT WHERE SUCH GROUNDING IS EXPLICITLY SHOWN ON DRAWING 22 TEST POINT EE NO RUN OR JOG 2 Capacitor C13 charges This is not sufficient to fire Q6 before the next synchronizing pulse V v arrives ee Decor NOTE Output error amplifier L1 will be approximately zero volts Figure 15 AC DC Relays 6 6 TRANSFORMERS Transformers shall be connected to conform with data wey on the transformer nameplate to obtain correct voltage u for input to control NOTE SCOPE REFERENCE COMMON TO TB1 13 UNLESS OTHERWISE INDICATED 6 6 1 TEST POINTS 1 WO6 or Cathode D1 4 TEST POINT EE DRIVE IN RUN OR JOG Negative going full wave rectified waveform used Low clutch voltage 10 volts to synchronize phase control circuit Note Output of L1 positive approximately 5 volts Q6 fires at indicated peaks 13V 30V ov 2 BASE Q5 5 TEST POINT EE DRIVE IN RUN Positive pulse at base of Q5 turns on transistor Q5 to discharge timing capacitor C13 each time High clutch voltage 75 volts f line goes to zero volts synchronizing C13 to line Note Ou
23. CEDURE 1 Set controls adjustments and switches to initial positions 2 Apply main power to the control and drive 3 Press AC MOTOR START push button Listen to assure operating speed is attained prior to performing step 4 4 Press RUN push button 5 Rotate SPEED control to 10096 setting As drive begins to rotate check for correct direction of rotation If drive is running backwards open main circuit and inter change two AC motor connections at the AC motor 6 Adjust MAX SPEED adjustment until maximum speed equals rated top speed indicated on nameplate 7 Adjust operators speed potentiometer fully counterclockwise 8 Increase MIN SPEED adjustment setting until drive begins to rotate and then decrease setting until drive stops If it is desirable to have drive rotate at some minimum speed with SPEED control set at zero then increase setting of MIN SPEED adjustment until drive is rotating at desired speed 9 Increase operators SPEED control setting until drive is running at desired run speed 10 Decrease STABILITY adjustment setting until drive instability or hunting occurs then increase adjustment setting until hunting stops 11 Set GAIN adjustment for desired regulation Best regulation is attained at 10096 setting If drive instability or hunting occurs reduce setting of this adjustment NOTE GAIN AND STABILITY ADJUSTMENTS INTERACT NORMALLY THEY ARE SET FOR OPTIMUM REGULATION WITHOUT HUNTING
24. EDBACK CIRCUIT 237 SYMPTOMS 1 RETER TO MANUAL SECTIONS OPERATION amp FUNCTIONAL DESCRIPTION HOW TO USE A MULTIMETER wn CHECKING COMPONENTS L1 L2 WITH AN OHMMETER DEPRESS RUN SCHEMATIC 1235 BUTTON A APPLY POWER 115 VAC TO TB 1 NOTE THIS CIRCUIT IS BEST TROUBLESHOT USING AN OSCILLOSCOPE CHECK SECTION ON TYPICAL WAVEFORMS TO AID IN LOCATING THE DEFECT IF ADDITIONAL DRIVE WILL NOT RUN POWER SUPPLIES OK RELAY CIRCUITS OK REFERENCE amp ERROR AMPLIFIER CIRCUITS CIRCUIT OK ERROR AMP OUTPUT SATURATED 15 VOLTS AT TP K DRIVE WILL NOT TURN OFF WITH REFERENCE POT AT ZERO AND ERROR AMP OUTPUT AROUND ZERO VOLTS TP K HELP IS NEEDED CALL FIELD SERVICE DEPARTMENT SYMPTOM METER DC VOLTS RANGE 30VDC RED LEAD TO TP 3EE EMITTER Q6 BLACK LEAD TO TB 1 15 ERROR AMP SATURATED 15V AT TP K METER DC VOLTS RANGE 30VDC RED LEAD CATHODE OF DZ4 JUNCTION 024 R13 amp R24 BLACK LEAD TO TB 1 15 METER 8v METER READS 8V READS 8 5 VOLTS 8 5 V OK MOVE RED METER LEAD TO CATHODE OF DZ4 JUNCTION OF DZ4 R13 amp R24 METER READS YES SHUT OFF POWER CHECK Q5 amp Q6 FOR COMPONENT FAILURE REPLACE DEFECTIVE COMPONENT SHUT OFF POWER CHECK DZ4 FOR OPEN HAS K2 CONTACT CLOSED TO SUPPLY 115 VAC TO SCR DIODE POWER CUBE METER AC VOLTS RANGE 120V RED LEAD TOR B
25. EED SETTING 15 VOLTS CHANGING THE SETTING OF P1 ACCEL RATE WILL CHANGE THE RATE AT WHICH THE VOLTAGE AT PIN H WILL INCREASE NOTE TURNING SPEED POT COUNTERCLOCKWISE WILL CAUSE THE VOLTAGE TO DECREASE RAPIDLY REPLACE Q1 REPLACE D3 4 REPLACE K1 READS 5 VOLTS SHUT OFF p POWER CHECK Q1 OR Q3 READS REVERSE SOME POSITIVE VOLTAGE SHUT OFF POWER p CHECK Q3 FOR COLLECTOR BASE SHORT i SHUT OFF POWER OMMETER CHECK DIODE D3 APPLY POWER AGAIN DOES K1 NORMALLY CLOSED CONTACT 11 3 OPEN WHEN RUN BUTTON IS PRESSED OK v SHUT OFF POWER CHECK CA 100MF 35V CAPACITOR FOR SHORT CHECK FOR SHORTED TRACES DUE TO FOREIGN MATTER ON TRACES OR BETWEEN PARTS ON BOARD SCR CONTROLS FlowChartSpeedReference Cireuit vsd 9 27 2007 MELLTRONICS NDUSTRIAL TROUBLESHOOTING CHART 10 SPEED REFERENCE CIRCUIT 36 SYMPTOMS 1 DRIVE FAILS TO RUN 2 RUNS AT FULL SPEED POWER SUPPLIES RELAY CIRCUITS OK REFERENCE CIRCUIT OK FEEDBACK CIRCUIT TESTS ON OFF OPERATION APPLY POWER DRIVE RUNS TO TOP SPEED AC TACH IS CONNECTED TO TB 1 11 12 METER AC V RANGE 100 VOLTS RED LEAD TO TB 1 11 BLACK LEAD TO TB 1 12 METER READS TACH VOLTAGE SPEED ARE BOTH SET MAX COUNTERCLOCKWISE DRIVE WILL TURN OFF WHEN SPEED PO
26. INSTALLATION OPERATION MAINTENANCE TRONICS DRIVES EDDY CURRENT CONTROL Melltronics Industrial Inc MAIL PO BOX 2368 INDIAN TRAIL NC 28079 2368 SHIPPING 3479 GRIBBLE ROAD MATTHEWS NC 28104 8114 PHONE 704 821 6651 www melltronics com SAFETY WARNINGS Improper installation or operation of this drive control may cause serious injury to personnel or equipment Before you begin installation or operation of this equipment you should thoroughly read this instruction manual and any supplementary operating instructions provided The drive must be installed and grounded in accordance with local and national electrical codes To reduce potential of electric shock disconnect all power sources before initiating any maintenance or repairs Keep fingers and foreign objects away from ventilation and other openings Keep air passages clear Potentially lethal voltages exist within the control unit and connections Use extreme caution during installation and start up BRANCH CIRCUIT PROTECTION Branch circuit protection is to be provided by end user OVERLOAD PROTECTION Overload protection must be provided per national electric code article 430 Section C INITIAL CHECKS Before installing the drive control check the unit for physical damage sustained during shipment Remove all shipping restraints and padding INSTALLATION LOCATION OF CONTROL Controls are suitable for most factory areas where industrial equipment is
27. L2 600 ohms Bridge Diode R1 removed SECTION 7 START UP INSTRUCTIONS The operating and start up adjustments outlined in this section describe the normal operating procedure Eddy current control model 1235 and associated drive system equipment has been tested and subjected to quality control inspection prior to shipment However visual inspection and preliminary testing must be performed before system is energized 7 1 GENERAL START UP PROCEDURE Refer to applicable eddy current schematic and interconnecting diagram that is supplied with each system when connecting control and drive motor 7 2 SAFETY PRECAUTION 1 The drive will remain uncoupled from the load until preliminary testing is completed 2 All personnel except operator shall remain clear of machinery and drives throughout initial start up 7 3 PRELIMINARY TESTS WARNING PRIOR TO RESISTANCE CHECKS DISCONNECT ALL AC POWER TO THE CONTROL Use an ohmmeter to measure resistance to ground DO NOT use Megger Bellringer or Buzzer as damage to semi conductors may result Measure resistance on all eddy current terminal strips including coil to earth ground Meter should read greater than 100 000 Ohms at all points 73 1 VISUAL INSPECTION 1 Check all interconnecting wires for conformance to supplied schematics 2 Check operation of movable components switches etc manually for freedom of movement 3 Check for damaged internal wires
28. LACK LEAD TO S APPLY POWER TO TB 1 L1 L2 115 DEPRESS RUN BUTTON METER READS APPLIED POWER 115 IF NOT SHUT OFF POWER CHECK K2 CHECK WIRING TO POWER CUBE Y SHUT OFF SHUT OFE POWER POWER SHUT OFF POWER CHECK Q6 FOR OPEN CHECK FOR CHECK FOR OPEN EMITTER BASE PEN DZ Q5 OR DEFECTIVE JUNCTION CHECK T1 4 On FOR OPEN PRIMARY REPLACE IF THERE IS STILL NO OUTPUT SCR S FAIL TO FIRE REMOVE GATE LEADS FROM BLOCK X amp W MAKE SURE POWER IS OFF WITH OHMMETER CHECK EACH SECONDARY OF 1 CHECK POWER CUBE lt FlowChartSCRPhaseControlPowerOutputCircuitsvsd 9 27 2007 SCR MELLTRONICS CONTROLS INC INDUSTRIAL INC TROUBLESHOOTING CHART 12 SCR PHASE CONTROL amp POWER OUTPUT CIRCUITS 38 SECTION 9 Spare Parts List Quantity Description Part Number 5 Fuse 314015 1 Rectifier Block WV2BE21C 1 Diode Bridge WO6 2 Zener diode 15v 1N4744A 2 Zener Dioce 10v 1N4740A 2 Zener Diode 8 2 1N4738A 2 Diode 1N4003 2 Diode 1N914 1 Diode 1N93 2 Transistor 991 3N 2 Transistor 991 2P 1 Unijunction Transistor 2 4871 1 Linear Amp LM741CN 1 Pot 1K 2W 916 7102 1 Pot 15K 2W 916 715 3 1 Pot 100K 3389P 1 104 1 Pot 500K 3389P 1 504 1 Relay 3510 001 4PDT 120VAC 1 Relay W88KDV 3 SPST 24VDC 1 Relay 78RE 24VDC SPDT 24VDC Electrostat Repair Kit 1235 45 1 Kit Less R
29. LTS POS LEAD TB 1 15 NEG LEAD TP H METER READS SPEED REFERENCE AND FOLLOWS SPEED BLACK METER LEAD TO TP 1 METER READS SPEED REFERENCE AND FOLLOWS SPEED POT SETTING AS ABOVE MOVE RED METER LEAD TO TP K OUTPUT OF L1 BLACK LEAD TO TB 1 15 METER READS NO REFER TO SCR PHASE CONTROL TROUBLESHOOTING GUIDE YES BIAS POT P8 CLOCKWISE REFER TO SCR PHASE CONTROL TROUBLE SHOOTING GUIDE REFER TO MANUAL SECTIONS 1 RUN RELAY CIRCUITS 2 HOW TO USE A MULTIMETER 3 CHECKING COMPONENTS WITH AN OHMMETER 4 SCHEMATIC 12351 NO REFER TO SPEED REFERENCE CIRCUIT TROUBLESHOOTING NO v A JUMPER SHOULD BE INSTALLED BETWEEN H amp I CHECK CONNS AND REPAIR IF NECESSARY CHECK CONNECTIONS FROM JOG OPTION BOARD TO MAIN BOARD NG REPAIR OR REPLACE REFER TO JOG OPTION TROUBLESHOOTING GUIDE IF DRIVE RUNS UNDER CONTROL DOES NOT GO TO TOP SPEED SHUT OFF POWER amp CHECK COMPONENTS FROM TP I TO TP P FOR OPENS NOTE JUMPER SHOULD BE INSTALLED BETWEEN TP J AND FOR NORMAL OPERATION IF DRIVE RUNS UNCONTROLLED CLUTCH ON OR OFF CHECK FEEDBACK CIRCUIT FlowChartErrorAmplifier FeedbackCircuitvsd 9 25 2007 MELLTRONICS INDUSTRIAL INC O CONTROLS INC TROUBLESHOOTING CHART 11 ERROR AMPLIFIER amp FE
30. Melltronics goods without incurring any obligation to similarly alter goods previously purchased Melltronics Industrial Inc MAIL PO BOX 2368 INDIAN TRAIL NC 28079 2368 SHIPPING 3479 GRIBBLE ROAD MATTHEWS NC 28104 8114 PHONE 704 821 6651 www melltronics com
31. N RELAY SOCKET NG ENERGIZED K1 OPERATES OK K2 FAILS TO ENERGIZE DC VOLT RANGE 30VOLTS RED LEAD TB 1 15 BLACK LEAD PINY READS 30V REFER TO POWER SUPPLY TROUBLE SHOOTING GUIDE SHUT OFF POWER CHECK FOR BROKEN TRACES OR lt RELAY SOCKET CONNECTIONS RECHECK FOR LATCH OPERATION OF CONTACT 9 5 PROBLEM CORRECTED MOVE BLACK LEAD SHUT OFF POWER CHECK K1 RELAY CONTACTS 10 amp TEC S b2 6 FOR OPERATION REPLACE lt N RELAY IF BAD OTHERWISE EON MAP CHECK TRACES TO RELAY SOCKET Ks ENERGIZED PROBLEM CORRECTED DOES 30V SUPPLY DROP WHEN K1 IS PICKED UP SHUT OFF POWER CHECK FOR SHORTED DIODE D12 CHECK FOR OPEN TRACES TO K2 OR SHORTED TRACES DUE TO BLACK LEAD OR OPEN K2 COIL MUST BE FOREIGN MATTER ON TRACES ANODE OF D2 REMOVED FROM BOARD TO BE BETWEEN PARTS ON BOARD READS 30VDC CHECKED PROPERLY SHOULD READ 400 OHMS IF DEFECTIVE REPLACE SHUT OFF POWER CHECK FOR OPEN D2 BEFORE REPLACING D2 CHECK FOR SHORTS AS LISTED IN BOX TO FlowChartRunRelay LEFT Circuit vsd 9 25 2007 SCR MELLTRONICS IF OK REPLACE D2 CONTROLS INC INDUSTRIAL INC TROUBLESHOOTING CHART 9 RUN RELAY CIRCUIT 35 SHUT OFF POWER CHECK TRANSISTOR Q3 991 3N SHUT OFF POWER CHECK TRANSISTOR Q4 991 2P NG
32. NG CHART 12 SCR PHASE CONTROL amp POWER OUTPUT CIRCUITS 38 SECTION 1 INTRODUCTION This operating and maintenance manual contains necessary information for normal installation operation and maintenance of Eddy Current Control Model 1235 The Operator and or Maintenance Personnel should have access to a copy of this Instruction Book The purpose of this book is to provide basic operating and technical information applicable to the Eddy Current 1235 Control It does not cover all details or variations in this equipment and should be applied in conjunction with specific schematics drawings and engineering advice provided by Melltronics 1 4 DESIGN Eddy Current Drives utilize a design to maximize electronic response and operational efficiency Compact rugged physical solid state construction allows control and drive to be located in adverse environments with reliable operation 1 2 SAFETY Multiple safety features protect the control and associated equipment from possible damage due to drive overload line loss transients and other electrical or mechanical failure Normal operator adjustments are located on isolated front panel to reduce hazards of possible electrical shock when system requires adjustment L TT JI HIGH VOLTAGE Erg mE SECTION 2 GENERAL INFORMATION 2 11 STANDARD OPERATION FEATURES 1 Same basic low cost control for all drive models 1 to 900HP 2 Compact 8 x 10
33. NSTRUCTIONS ON INSTALLATION OF SHIELDS CHECK CONNECTIONS ON CONTROL VISUALLY LIFT P C BOARD amp LOOK FOR ALL SOLDERED CONNS ON FOIL SIDE IF THE FEEDBACK TACH IS NOT THE AC TACH INTERNAL TO THE DRIVE SEE THAT THE TACH COUPLING TO THE DRIVE IS TIGHT 90 m DOES DRIV STILL WANDER IN SPEED SEE TROUBLESHOOTING GUIDE SPEED REFERENCE CIRCUIT TROUBLESHOOTING CHART 2 DRIVE SPEED UNSTABLE SEE PERFORMANCE OPTIMIZATION ADJUSTMENTS TROUBLESHOOTING CHART 3 SPEED REGULATION NOT WITHIN SPECIFIED LIMITS 1800 RPM A C MOTOR OR LESS 3600 RPM Y REMOVE O TO P JUMPER ON P C BOARD Y IF INSTALLED CHECK SPEED POT WIRING 4 y v IF D C TACH GEAR IN SHOULD PRODUCE APPROX 80V AT MAX RPM WITH O TO P JUMPER INSTALLED OR 160V WITH O TO P JUMPER REMOVED FlowChartMaximumSpeedPotNot AbleToCauseTopSpeedvsd SEE TROUBLE SHOOTING INSTRUCTIONS 9 25 2007 SPEED REFERENCE CIRCUIT MELLTRONICS INDUSTRIAL INC CONTROLS INC TROUBLESHOOTING CHART 4 MAXIMUM SPEED POT NOT ABLE TO CAUSE TOP SPEED OF DRIVE 31 DRIVE RUN YES WHEN A C MOTOR IS STARTED WITH CONTROL OFF K2 NERGIZED COUPLE IS DRIVE DB PAD COUPLED TO NO LOAD CHECKFOR 1 SIEZED PILOT BEARING 2 FOREIGN MATERIAL BETWEEN INPUT AND OUTPUT ROTORS
34. R DISCONECT TACH LEADS FROM TB 15 amp 16 PLACE A C V M ON TACH LEADS TO TB 1 15 amp 16 AT CONTROL END START DRIVE CAUSE DRIVE TO RUN TO FULL SPEED BY TURNING UP SPEED POT IF FULLY SEE MULTIMETER OPERATING INSTRUCTIONS RESISTANCE MEASUREMENT CHECK RESISTANCE OF A C TACH amp LEADS TO CONTROL YES Y REVERSE LEADS TO RESTORE CORRECT POLARITY POLARITY OK TACH DRIVEN BY DRIVE DIRECTLY OR THRU BELT OR GEAR IN PLACE MATERIAL IN LINE TO MOVE TACH WHEN DRIVE TURNS Y REPEAT START UP INSTRUCTIONS IS TACH CURRENT GEN 15 POSSIBLE SHORTED DIODES D4 D5 06 OR D7 CHECK OUT PER INSTRUCTION OMMETER COMPONENT CHECKS AMMETER 8 10 OHMS MEASURED LEAVE OMMETER ON WIRES SHORT METER LEADS TOGETHER TO CLEAR METER REMOVE INSTALLATION FROM TAPED LEADS AT DRIVE END TOUCH LEADS TOGETHER TACH PROBABLY OPEN DISCONNECT TACH LEADS FROM TACH TO DRIVE OBSERVE METER DOES METER READ Low OHMS DOES LOW OHM INDICATION PERSIST YES OPEN TACH LEADS TO CONTROL FROM DRIVE v SEE MULTIMETER OPERATING INSTRUCTIONS D C VOLTAGE MEASUREMENT PLACE BLACK LEAD ON TB 2 15 PLACE RED LEAD ON TB 2 16 YES v DOUBLE CHECK TROUBLESHOOTING CHART WITH SPEED POT TO C C W FULLY MIN SPEED POT C C
35. S FULLY amp WITH BIAS POT C C W FULLY PUSH RUN P8 POSSIBLE OPEN DIODES D4 D5 D6 OR D7 CHECK OUT PER INSTRUCTIONS NO LEADS TO TACH TACH FROM CONTROL PROBABLY SHORTED SHORTED DOUBLE CHECK MOVE OMMETER FROM WIRES AT CONTROL END CHECK PLACE OMMETER ON TACH LEADS DIRECTLY AT DRIVE CONFIRM TACH FAILURE CONSULT MELLTRONICS SERVICE DEPARTMENT HAVE INFORMATION AVAILABLE 1 INFORMATION ON DRIVE NAMEPLATE 2 ORDER AND OR JOB NUMBER TROUBLESHOOTING CHART 5 32 FlowChartDriveRunsToFull SpeedNotUnderControlvsd DRIVE RUNS TO FULL SPEED NOT UNDER CONTROL CAN SPEED POT BE REDUCED BY ROTATING HE SPEED POT C C W SEE TROUBLESHOOTING INSTRUCTIONS DRIVE RUNS TO HIGH SPEED NOT UNDER CONTROL FlowChartMaxSpeedPotNotCapableOf SettingSpeedLow vsd 9 27 2007 MELLTRONICS INSTALLO TO P JUMPER IF NOT INSTALLED ee N TROUBLESHOOTING CHART 6 MAX SPEED POT NOT CAPABLE OF SETTING SPEED LOW ENOUGH SEE INSTRUCTIONS INSTALLING THE JOG OPTION IS OPTION INSTALLED OK CORRECT INSTALLATION HAS JUMPER H TO I BEEN REMOVED FROM MAIN BOARD SEE MULTIMETER INSTRUCTIONS A C VOLTAGE MEASUREMENT PLACE METER FROM TB 10 2 TO TB 4 1 ON JOG OPTION BOARD PUSH JOG P B DOES K2 PICKUP WHEN
36. T IS TURNED TO ZERO NOTE MIN SPEED P2 amp BIAS P8 YES CHECK EXTERNAL TACH CONNS ALSO FOR METER DC TACHS DC VOLTS RANGE 100V RED LEAD TB 1 10 BLACK LEAD 5B 1 15 METER READS A VOLTAGE WHICH REPRESENTS DRIVE OUTPUT YES SHUT OFF POWER CHECK COMPONENTS FROM TB 1 10 TO CHECK EXTERNAL TP P FOR OPENS OR SHORTED TACH CONNS CAPACITORS C9 OR C10 NOTE JUMPER SHOULD BE INSTALLED BETWEEN TP O TO TP P IF THE FEEDBACK TACH IS NOT THE A C TACH INTERNAL TO THE DRIVE CHECK TO SEE THAT THE COUPLING FROM THE DRIVE TO THE TACH IS FREE OF BACKLASH DRIVE SHUTS OFF ONLY WHEN STOP BUTTON IS DEPRESSED TURNING SPEED POT MIN SPEED POTP2 amp BIAS P8 MAX COUNTERCLOCK WISE DOES NOT SHUT OFF CLUTCH VOLTAGE v METER DC VOLTS RANGE 30 VOLTS RED LEAD TO TP K BLACK LEAD TO TB 1 15 METER READS NEAR ZERO 15V REFER TO SCR PHASE CONTROL TROUBLESHOOTING GUIDE lt v L1 APPARENTLY DEFECTIVE SHUT OFF POWER BEFORE REPLACING Lig CHECK BOARD FOR POSSIBLE SHORTS BETWEEN TRACES OR COMPONENT LEADS IF NO PROBLEMS FOUND REPLACE L1 115VAC TO TB1 L1 L2 DEPRESS RUN PUSH BUTTON ADVANCE SPEED POTENTIOMETER FAILS SECTIONS LISTED UNDER YMPTOMS HAVE CHECKED AND FUNCTION PROPERLY METER DC VOLTS RANGE 30VO
37. TTING WARM DC VOLTS RANGE 30VDC POS LEAD TB 1 15 NEG LEAD PIN F READS 15V 10 SHUT OFF POWER R3 IS OPEN CHECK WITH OHMMERTER REPLACE SUPPLY METER D VOLTS RANGE 30VDC NEG LEAD TB 1 15 POS LEAD PIN D READS 15V 10 IS R2 390 OHMS 3 1 4 RESISTOR GETTING WARM 10V REFERENCE SUPPLY SHUT OFF POWER R2 IS OPEN CHECK WITH OHMMETER REPLACE 30VDC POS LEAD TB 1 15 NEG LEAD TB 6 READS 10V 10 DC POWER SUPPLIES ARE OK WO6 OPEN REPLACE WITH GOOD WO6 MOVE DCVOLTSRANGE NEG METER LEAD TO SHUT OFF POWER THERE APPARENTLY IS A SHORT ON THE 15V LINE POSSIBLE CAUSES DZ1 DEFECTIVE C16 CAPACITOR DEFECTIVE L1 OPERATIONAL AMPLIFIER DEFECTIVE Q3 DEFECTIVE TRACES SHORTED DUE TO FOREIGN MATTER ON TRACES OR BETWEEN PARTS ON BOARD anon CHECK SECTION FOR METHOD OF CHECKING COMPONENTS WITH AN OHMMETER CHECK EXTERNAL WIRING TO AND 8 IS PREVIOUS MEASUREMENT AND WIRING ON THE SPEED POT ITSELF SHOULD BE 5000 OHMS SPEED POT FOR SHORTS TO SHIELD OR BETWEEN WIRES CHECK VALUE SHUT OFF POWER CHECK R4 RESISTOR AND DZ3 AND REPLACE DEFECTIVE COMPONENT TROUBLESHOOTING CHART 8 POWER SUPPLY 34 FlowChartPowerSupply vsd 9 25 2007 SCR A A MELLTRONICS CONTROLS INC TRU C REFER TO MANUAL SECTIONS RUN RELAY CIRCUITS HOW TO
38. and components 4 Check for AC supply voltage for correct frequency 5 Check transformer output voltage prior to connecting to drive 6 Check that the mechanical eddy current drive rotates freely by hand 7 Check that the operators speed potentiometer is connected properly per the control connection diagram The speed reference potentiometer supplied with the control is S N 990 35 5K 1 W with a minimum of 500 volts insulation from the shaft or mounting surfaces to the electrical parts The lead connections at the potentiometer should be taped using high voltage insulation tape The operator s speed adjustment should be connected LEAD OHMMETER LEAD SHORT A Figure 16 Operator s Speed Adjustment 8 Before proceeding insure start stop circuitry is functional before attempting to rotate motor Control and Adjustment Location Operator s Station a Run push button green energizes relay K1 b Stop push button black de energizes C E Stop d Operators Speed adjustment adjustment determines motor speed increases speed position of Clockwise 9 If a DC tachometer is used for feedback place a DC voltmeter positive lead on customer terminal strip 10 and negative lead on terminal 13 and rotate drive in the normal running direction The voltmeter will measure positive voltage when the tachometer is correctly connected 26 7 44 BASIC CONTROL SET UP 1 Operator s Con
39. diodes D4 through D7 rectifies AC tachometer voltage to DC This voltage is applied to R15 R16 and R17 in series Capacitor C9 and C10 provide filtering for the feedback signal NOTE WHEN AN 1800RPM DRIVE IS USED H18 IS JUMPERED OUT Since the summing junction of the error amplifier is at virtual ground the current is Voltage at 10 I fb R15 R16 R17 This current is the speed feedback current DC tachometer may be connected as shown above in place of an AC tachometer SPEED METER Current for the speed meter is provided through R19 and meter calibrate potentiometer P4 supplied by the rectified AC tachometer voltage or DC tachometer voltage 14 I REFERENCE ray tal NEGATIVE REFERENCE D a O Ri FROM SPEED REFERENCE CIRCUIT H OR SEE OPTION BOARD P3 15K MAX SPEED I FEEDBACK R17 POSITIVE SPEED FEEDBACK BIAS 15V I STABILITY REMOVE JUMPER FOR 3600RPM P5 STABILITY PI A A R18 TO PHASE CONTROL CIRCUIT DC COMMON Figure 7 Error Amplifier Circuit 5 5 ERROR AMPLIFIER CIRCUIT 5 5 1 OPERATION The voltage at A i e bias potentiometer counter clockwise is generated by the output of the speed reference circuit or if the jog option is used is generated by the potentiometer across the minus power supply See description of Jog Option Board The voltage at B with voltage A is approximately zero at a level from minus 0 5 to slightly
40. ectifier Block Hi Par Driver P C Assy 39 SECTION 10 REVISION HISTORY REV DATE DESCRIPTION REVISIONS NONE 12 23 03 17 RELEASE NONE A 05 23 08 PAGE 21 FIG 14 BASIC CORRECTIONS REDRAWN AND CONTROL DRIVE INTERCONNECTIONS SUBSTITUTED 40 NOTES 41 NOTES 42 SECTION 11 WARRANTY MELLTRONICS warrants to the Buyer whom purchases for use and not for resale that the equipment described in this instruction manual is sold in accordance with published specifications or the specifications agreed to in writing at the time of sale Melltronics further warrants that such goods are free of defects in material and workmanship The warranty shall apply for a period of twelve months 12 from date of purchase not to exceed eighteen months 18 from the date of manufacture If the goods fail to perform to Melltronics specifications as outlined in the warranty then Buyer should contact Melltronics to obtain a Material Return Authorization MRA prepare the goods for shipment and return the goods to Melltronics for repair or replacement at Melltronics option Buyer will bear all costs of transportation to and from Melltronics factory
41. erminal is negative Common terminal is positive This meter allows the use of this switch to reverse the test voltage Other meters without this feature will require reversal of the test leads at the points under test 24 Remove ALL POWER from circuits when making Resistance measurements Approximate readings indicate readings depend on non linear elements such as diodes transistors etc Large capacitors also cause some readings to deviate from stated resistance readings A capacitor will cause the initial resistance to read zero ohms then increase to some minimum value as stated The rate at which the resistance increases depends on the size of the capacitor resistances in the circuit and meter and current supplied by the meter to charge the capacitor Connect Meter common to TB2 15 NOTE NO EXTERNAL CONNECTIONS ON TB1 OR TB2 PINREADS 1 oo Infinity 2 00 3 00 4 00 5 00 6 1K 30K 7 47K 8 0 to 1K depends on min speed pot setting 9 00 25 10 50K 2000hms 11 50K 2000hms 12 50K 2000hms 13 10 ohms or less 14 Greater than 100K 6 7 CLUTCH CIRCUIT no external connections to L1 L3 L1 and L2 Meter Lead Lead To To C1 C2 1 400 ohms C1 C2 Ri removed C2 C1 600 ohms R1 removed C1 L1 Both directions R1 removed SCR resistance C1 L2 Both directions R1 removed SCR resistance C2 L1 600 ohms Bridge Diode R1 removed C2
42. es a minimum SCR current Without this resistor the SCR may not conduct because the inductive load clutch may not allow holding current to be attained during the duration of the gate pulse C2 Resistors RC2 RC3 and RC4 provide a low impedance shunt path for noise and line spikes which are prevalent in industrial environments A voltage suppressor provides over voltage protection for the rectifier block CLUTCH Figure 11 Bridge and Coil Current Conduction L1 L2 18 1235 7 I JOG OPTION PCBOARD 15V F SELECT CAP TO MODIFY JOG ACCEL RATE IF DESIRED RATED 15 VOLTS OR HIGHER oe o PIN 9 Figure 12 Jog Option Board 5 8 JOG OPTION BOARD 5 8 1 OPERATION When jog option board is used the normal jumper connection between the output of the ramped reference H and the input to the error amplifier circuit is opened and reconnected through H and I of the jog option board When JA relay energizes a negative voltage is applied to the input of the error amplifier through the max speed potentiometer and resistor R11 The connection to the ramp generator output is opened Normally open contact of JA 12 8 connect K2 K3 and K4 to 24VDC at Y The function of these relays is the same as described Figure 4 Jog relay JA is inoperative when relay K1 run relay is energized when Jog button is connected between TB4 terminal 1 and TB2 terminal 9 If desired t
43. he rate of acceleration to the jog speed may be modified by placing a capacitor 15V rating or more as shown in Figure 12 19 pom HE s w m m s wm UJ o BRAKE 90V 750 ma MAX 115VAC Figure 13 Friction Brake Option 5 9 FRICTION BRAKE OPTION BOARD 5 9 11 OPERATION Wires A S and C are connected to the main board to corresponding letters When 2 is energized and the main control de energized 90VDC approximately is applied to the friction brake When K2 energizes relay BCR N C contacts open and the friction brake is released This option is for a voltage engaged brake Other brake options are available for voltage AC or DC released brakes fail safe and for applying a variable DC voltage to the brake 20 SECTION 6 INSTALLATION 6 1 DESIGN The enclosure is designed for either floor or wall mounting depending on customer and horsepower requirement The control should be installed in a well ventilated area Unless designed for special conditions the enclosure cabinet should be located using the following criteria 6 2 CRITICAL ENVIRONMENTAL FACTORS Ambient Temperature should not exceed 104 F 40 C Ambient Temperature should not fall below 50 F 10 C Enclosure s circulating air should be clean dry and free from flammable or combustible vapors corrosive gasses solids or
44. hile in module 2 Connect the positive ohmmeter lead to SCR cathode and Negative meter lead to anode Resistance should be one megohm or more 3 Reverse meter leads Resistance should be one megohm or more 4 Temporarily jumper the gate to anode with the meter connected See Figure 17 Resistance should be one thousand ohms or less SHORT LEAD A Figure 17 Temporary Jumper Gate to Anode 84 COMPONENT TESTING NOTE DISCONNECT ALL AC POWER TO CONTROL PRIOR TO PERFORMING THE FOLLOWING COMPONENT TESTS Resistors Fixed resistors can be tested in a circuit by disconnecting one lead and measuring resistance with ohmmeter on respective ohm scale Potentiometers Tested by disconnecting all but one lead from the circuit and measuring resistance Transformers Can be tested by continuity or short circuits by referring to winding connector drawing on nameplate Relays Can be checked by a resistance test on the continuity test across contacts or by replacement Capacitors A good capacitor will cause ohmmeter needle to jump toward zero when leads are first connected Then the needle will move toward the maximum scale Open Capacitor Ohmmeter needle will remain at maximum reading Shorted Capacitor Zero Ohms Leaky Capacitor Fixed resistance reading 29 SEE TROUBLE SHOOTING INST POWER SUPPLY Y SEE TROUBLE SHOOTING INSTR
45. i en d utin 5 SECTION 2 GENERAL INFORMATION U U U u uu uu uu uu uu 6 2 1 STANDARD OPERATION FEATURES 6 2 2 STANDARD SAFETY FEATURES eee ease aw e bat decken 6 2 3 STANDARD ADJUSTMENTS 2 3 nde extre Peri o ta e epi etel ie ee deiecit end 6 2 4 AVAIEABLEE OPRT IONS cit tee op tt detestatur dais 6 2 5 SPEGIFICATIONS Re 4 2 eu Iudei Ed oie dius 6 SECTION 3 DESCRIPTION peer ru 7 3 1 SGHEMATIGS t tent t tec e e e tete e Pet t een at a Lr es HT cc ene Haba bus 7 3 2 ADJUSTMENTS en nece ep er Ree ett mes edite 7 SECTION 4 THEORY OF OPERATION ced tnc ei ee i anra pace rd Lade sani 8 4 1 DRIVE OPERATION eei er ete e i e dee Dreh tu ett sce eig 8 4 2 OPERATION OF BASIC EDDY CURRENT CONTROL 8 SECTION 5 CIRCUIT DESCRIPTION i Drs 10 5 1 POWER SUPPLY x ee ee ee ed a a 10 5 2 RUN RELAY CIRCUIT A meme petite dee pter lees a 12 5 3 SPEED REFERENGE GIRGUIT tdt ee ee Mean ensure 13 5 4 SPEED FEEDBACK CIRGUIT ie te an nen BE edem 14 5 5 ERROR AMPLIFIER CIRGUIT L ente seen Eieiie iiie 15 5 6 PHASE CONTROL GIREUIT iie ta eerte ee Een En E AE ear e IE ds 16 5 7 POWER OUTPUT CONTROL terme ee ea esse rr c a Haa cius 17 5 8 JOG ORTON BOARD tote tet edt erede te ehe putet te eet ep thee
46. installed The control and operators control station should be installed in a well ventilated area Locations subject to steam vapors or excessive moisture oil vapors flammable or combustible vapors chemical fumes corrosive gases or liquids excessive dirt dust or lint should be avoided unless an appropriate enclosure has been supplied or a clean air supply is provided to the enclosure The location should be dry and the ambient temperature should not exceed 104 F If the mounting location is subject to vibration the enclosure should be shock mounted If the enclosure has a ventilating fan avoid wherever possible and environment having a high foreign matter content otherwise the filters will have to be changed more frequently or micron filters installed Should a control enclosure require cleaning on the inside a low pressure vacuum cleaner is recommended not an air hose because of the possible oil vapor in the compressed air and its high pressure MELLTRONICS 1235 RECEIVING INFORMATION EDDY CURRENT MODEL PART NUMBER SERIAL NUMBER REVISION HORSEPOWER RATING VOLTAGE MODIFICATIONS ACCEPTANCE Carefully inspect shipment upon arrival and check items with packing list Shortage or damage should be reported promptly to the carrier and your distributor TABLE OF CONTENTS SECTION 1 INTRODUGTION mmc I A 5 14 DESIGN E 5 1 2 SAFETY Zana anata qatu gayi ut
47. itry and a power module 1235 1 CONTROL OUTPUT ROTOR Figure 1 Eddy Current Drive Schematic Alnigv1s d rU O O O O O RS ri O IN S O LNINLSNPAV q33dS SHO1VH3dO LINOUIO ONIH OUINOO 3SVHd NIVO lt D HOS totta X 1NIOd ONININNS 9GAO0 DANSL V 338 NOWWOO P pr KA Walid I 44MOd I HOVL OV O uaMOd HOLON IV Figure 2 1235 Eddy Current Control Basic Block Diagram SECTION 5 CIRCUIT DESCRIPTION 5 1 POWER SUPPLY 5 1 1 OPERATION The low voltage power supply converts 115VAC to unregulated 30 and 15 zener regulated DC voltage when 115 VAC is applied to the incoming line and K1 run relay is de energized and no external load 5 1 2 FUNCTIONAL DESCRIPTION Transformer T2 reduces 115VAC line voltage on the primary to 40 volts AC across 3 to 6 on the secondary Connections 4 and 5 provide a center tapped secondary connection WO6 rectifier provides full wave rectification of the secondary AC voltage Filter capacitor C1 has its positive terminal as common the volts AC from centertap to 3 and 6 provide a voltage of 21 VAC RMS Since the peak of a 21VAC waveform is approximately 30 volts the voltage on C1 negative terminal relative to common will be approximately 30 volts This occurs as C1 charges to the peak value of the wave Filter capacitor C2 the negative 30 volt supply is similar to the positive supply
48. liquids Enclosure should be shock mounted if location is subject to vibration Enclosure doors should have clearance to allow easy access to controls for inspection and maintenance WARNING EXTREME CARE MUST BE EXERTED DURING THE DRILLING AND OR CUTTING PHASE WHEN INSTALLING ELECTRICAL CONDUIT CARELESSNESS WILL CAUSE CHIPS AND PIECES OF METAL TO FORM SHORT CIRCUITS AND WILL RESULT IN NON WARRANTY DAMAGE 6 3 SHIELDED CABLE To avoid stray signal interference provide Belden 8208 2 conductor and or 8771 3 conductor shielded cable or their equivalents when interconnecting with e Speed potentiometer Jog potentiometer AC and DC tachometers Speed Indicators Ammeters The shield should be connected AT ONE POINT ONLY This point is at common not earth or chassis ground unless otherwise shown on schematic To avoid stray signal interference DO NOT run reference signal interconnecting wires in the same conduit or in close proximity to power wiring Armature leads and tachometer cable is to be routed separately for best operation Keep wire length as short as possible 6 4 EXTERNAL RELAYS When external customer AC and DC relays are connected to control adequate suppression networks are suggested across relay coil Arc suppression networks See Figure 15 prevent signal noise and extend life of relay contacts Specific installation should be reviewed by a qualified engineer
49. positive As speed reference voltage is applied to A the output of L1 operational amplifier See Figure 7 rises to a positive voltage at about 10 volts the phase controller will turn on the SCR s As the drive coil is excited torque is transmitted to the load and rotation of the output shaft and the tachometer occurs The speed feedback current reduces the output of L1 and the SCR output and equilibrium is reached where the drive speed is proportional to the voltage at A Increasing the gain with P7 requires that less current be supplied by the speed feedback circuit the drive speeds up With higher gain a small change in speed say due to drive loading produces a greater change in error amplifier L1 and the SCR output Potentiometers lead p6 and stability P5 provide a means for matching the dynamics of the control to the drive and load Maximum speed P3 ratios the value of reference current to the current obtained by the feedback generator and feedback circuit Since the various feedback voltages may represent maximum speed of the drive and the volts per RPM ratio of tachometers vary 15 BIAS ADJUSTMENT P8 Since the input signal at A may be produced at a very long rate say 40 seconds or 25V per second the offset in L1 may require a few seconds to get L1 up to a voltage where the phase controller will fire the SCR s Bias adjustment will raise the amplifier L1 output up to nearly the firing point DZ4
50. relay de energized or speed potentiometer turned down voltages at A and C are zero and nearly equal Current flowing through Q1 is diverted through D3 and R6 The emitter follower Q2 provides a low impedance sink for this current The Q2 B E voltage is cancelled approximately by the forward drop of D3 K1 relay closure provides current for zener diode DZ3 and the speed potentiometer through R4 from the minus 30V unregulated supply The reference voltage at terminal 46 provided by DZ3 will be 10V 5 As voltage is applied to A the current from Q1 which was diverted from charging C4 now charges C4 The current is diverted into D3 when C4 reaches a voltage approximately equal to A 13 Transistors Q3 and Q4 serve as a tandem emitter follower providing a high impedance input to C4 negative at the same time providing drive for the current input to the regulator as well as other regulators or ratio potentiometers for other optional regulators OPTIONAL DC TACH 4 O SPEED METER 0 100uA METER CALIBRATOR Potentiometer P1 controls the charging rate of C4 by setting the current through Q1 When K1 relay de energizes a normally closed N C contact 3 and 11 closes to quickly discharge C4 through R10 REMOVE JUMPER FOR 3600 RPM SUMMING JUNCTION TO ERROR AMPLIFIER L1 Figure 6 Speed Feedback Circuit 5 4 SPEED FEEDBACK CIRCUIT 5 4 1 OPERATION Full wave bridge rectifier
51. tput of L1 positive approximately 12 volts Q6 fires each time charge on C13 reaches 13 volts First pulse turns on the SCR the rest have no effect 6V 13V 6V 0V 23 6 B2 of Q6 DRIVE IN RUN Low clutch voltage 10 volts Sharp pulses coincide with Q6 firing presented in 4 15V 7 B1 of Q6 Same conditions as in 6 Firing pulses on primary of T1 pulse transformer WARNING THE FOLLOWING WAVE FORMS ARE REFERENCED TO THE AC LINE OR CLUTCH CIRCUIT AS SPECIFIED THE SCOPE COMMON MUST BE ISOLATED FROM THE AC LINE POWER TO SCOPE AND NOT TOUCHING GROUND IN ANY WAY DO NOT TOUCH THE SCOPE LEADS OR CASE AND GROUND AT THE SAME TIME HAZARDOUS VOLTAGES MAY BE PRESENT BETWEEN THE SCOPE AND GROUND 8 CLUTCH VOLTAGE 10VDC Scope connected across clutch common to C2 Probe to C1 Drive condition same as 4 50 0 8 Clutch voltage 75VDC Same hook up as 8 Drive condition same as 5 165V 6 6 2 RESISTANCE MEASUREMENTS NOTE POLARITIES ON RESISTANCE READING INDICATE POLARITY OF TEST VOLTAGE FROM OHMMETER APPLIED TO TERMINAL UNDER TEST CHECK POLARITY OF TEST VOLTAGE OF OHMMETER USED BEFORE ATTEMPTING TESTS RECOMMENDED METER SIMPSON 260 Positive terminal is positive in ohms position with switch in DC position Common terminal is negative Changing switch to DC position reverses test voltage at terminals Positive t
52. trol Station Set speed potentiometer fully counterclockwise 2 1235 control printed circuit board set controls Minimum speed P2 fully counterclockwise Maximum speed P3 fully counterclockwise Bias P8 fully counterclockwise Stability P5 midrange ead P6 midrange Gain P7 midrange Accel P1 fully counterclockwise Meter calibrate P4 midrange Jog speed P9 midrange Optional Adjustments 3 If AC drive motor is 3600RPM remove jumper O to P on the 1235 control 7 5 EDDY CURRENT ADJUSTMENT WARNING HIGH VOLTAGE MAY BE PRESENT AT SOME POINTS IN THE EDDY CURRENT CONTROL REGARDLESS OF WHETHER THE AC SUPPLY IS GROUNDED OR NOT THIS IS ALSO TRUE EVEN IF AN ISOLATION TRANSFORMER 15 USED IN THE AC THREE PHASE INPUT BECAUSE OF CAPACITIVE COUPLING WITHIN THE ISOLATION TRANSFORMER THE FOLLOWING PRECAUTIONS MUST BE TAKEN OPERATOR MUST NOT BE IN CONTACT WITH A GROUNDED SURFACE WHEN WORKING ON THE ENERGIZED CONTROL STAND INSULATED SURFACE WHEN A TEST INSTRUMENT IS BEING USED CARE MUST BE TAKEN TO INSURE THAT ITS CHASSIS IS NOT EARTH GROUNDED EITHER BY A GROUNDING PLUG CONNECTION OR BY BEING IN CONTACT WITH A GROUNDED SURFACE EXTREME CARE MUST BE TAKEN WHEN USING AN OSCILLOSCOPE SINCE ITS CHASSIS WILL BE ELECTRICALLY HOT TO GROUND WHEN CONNECTED THE CONTROL SYSTEM OSCILLOSCOPE MUST ELECTRICALLY FLOAT NO PART OF THE CONTROL SHOULD BE GROUNDED 7 5 1 SET UP AND ADJUSTMENT PRO
53. urrent coupling a control and operator s control station The drive unit consists of an AC induction motor driving the input member or fan pole assembly of the magnetic drive There is no mechanical linkage between input and output members of the drive Torque is transmitted from the AC motor to the load by eddy current action when the clutch field coil is excited with DC current Figure 1 The control supplies DC voltage to the drive field coils and automatically varies drive excitation to maintain desired speed torque tension position or horsepower as determined by the feedback signal The associated operators controls are those necessary for the operator to control the drive such as START and STOP pushbuttons and SPEED INPUT FAN AND POLE ASSEMBLY 4 2 OPERATION OF BASIC EDDY CURRENT CONTROL The control is used to regulate speed of the output member of the eddy current drive unit The control supplies regulated DC excitation to the magnetic drive field coil Drive excitation determines drive speed Speed regulation is accomplished by comparing signals which represent actual and desired speed The resultant error is used to produce an increase or decrease in drive excitation until actual speed equals desired speed The regulator section of the control maintains drive speed constant with feedback signal approximately equal to reference signal The basic regulator consists of a reference feedback stabilization circu
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