Centurion - Dental Lab & Equipment Repair
Contents
1. ug 3 _ TI 1 m ad TEF d TUNN 13538 8 IN Bi INSS 0817 4005 7005 9i zal dN AVY gin n4W RY _ Duns 21443 47123 alle Od A 49 a 7109 05 ANN KHANS WIMOd 9628 2 6 2 7 Diagnostic Tables Circuit Paragraph guide Power Supply Microprocessor Temperature Vacuum Current Sense Peripheral Motor Triac Display Symptom Display blank No or little Vacuum Press muffle up but muffle comes down again when in Nite Mode Muffle does not heat after power up No muffle movement after key is pressed Troubleshooting Schematic Tables Diagrams Table 2 1 Functional Circuit guides Possible Setup Error No line voltage Power switch failure J3 disconnected Check door insulation fit Rotate door 90 degrees Pump electrical connections Pump hose connections Temperature is approximately 100 C Press ESC One of the membrane keys made contact during power up Turn furnace off then on again Possible Vacuum inside chamber Rotate knob or press red button on back of unit Furnace is in TEST mode Motor connector J5 loose Furnace is running a firing cycle Press S S key and retry Table 2 2 Furnace Setup Common Errors Output Voltage Output Voltage Tolerance Ripple 350mV 0 02Vac 250mV 0 02Vac2. Table 2 3 Power Supply Voltages 9628 2 7 No dc output and no dc to U9 1 15 30V Low or no 12V dc output Nonfunctional operation Non responsive to membrane switches Power off Power off Disconnect J3 turn Power on Disconnect J3 Disconnect J2 F1 F2 T1 winding D40 41 42 C40 41 D43 C46 U9 2 U7 U10 39 X1 U10 1 3 34 40 U10 2 U10 16thru28 U10 12thru15 U10 Athru1 1 U10 29 30 U10 31 32 33 Listen 5V to U10 16 U10 17 U10 18 U10 19 U10 21thru28 Results desired 1 ohm Not shorted or open Not shorted or open Not shorted Not shorted or open Not shorted Pulse train of 2 No excessive heat Table 2 4 Power Supply Results desired 4MHz sinusoid approximately 0 4V gt 4 5V TP1 waveform digital low No stuck bits No stuck bits digital high No stuck bits Relay clicks Sonar Sonar beeps low strobe Table 2 5 Microprocessor 9628 All Y outputs high Turn furnace Off then On Turn furnace Off U16 11 Reset N A low Furnace in idle Disconnect J5 Turn furnace on Press Up arrow Press Down arrow Turn furnace off Turn furnace on No up or down Add mA meter in series at J5 At up or down position one LED stays off N A Muffle heats but display shows same temperature Erratic temperature display 2 9 U16 11 016 5 7 6 Display LED s D46 47 TP8 U4 A 1 013 11 DS20 21 DS21 DS20 D21 26 U13 15 Membr
3. 2 4 TROUBLESHOOTING COMPONENTS 2 4 1 Diode A diode except a zener is defective if there is greater than 1 Vdc typically 0 7 Vdc forward voltage across it 2 4 2 Operational Amplifier Generally the and inputs of an operational ampli fier will have less than 15 mV voltage difference when operating under normal conditions U3 U4 B U15 B When the output of the amplifier is connected to the input voltage follower connection the output should be the same voltage as the input voltage otherwise the amplifier is defective U17 A If the output voltage stays at maximum positive typically 1 3 of the supply voltage the input voltage should be more positive than the input voltage U17 B U18 A U4 A If the output voltage stays at minimum typically 1 5 mV the input voltage should be more positive than the input voltage U15 A 2 4 3 Triac The gate to power line return voltage K1 under load measures typically 1 2 Vac while the MT2 to return voltage measures between 1 3 1 8 Vac A triac without connections can be checked for a go no go condition with ohmmeter The gate to resis tance for a power triac 20 40A should be between 50 and 100 ohms there should be infinite resistance be tween 1 and 2 2 4 4 Capacitor Shorted capacitors have OV across their terminals Open capacitors can be located by using a good capaci tor connecte
4. DENSPL CERAMCO DENTSPLY International 13553 Calimesa Blvd Yucaipa CA 92399 2303 USA 909 795 2461 Fax 909 795 5268 CENTURION VPC VPM INTERVAC VPC 1 8 VACUUM FURNACE SERVICE MANUAL CSA TuV CE SAFETY FIRST Dont bypass the power 5 ground lead with two wire extension cords or plug adaptors Don t disconnect green and yellow safety earth ground wire that connects the ground lug of the power receptacle to the chassis ground Don t plug in the power cord until directed by the installation instructions Don t repair the furnace unless you are a qualified electronics technician and know how to work with hazardous voltages Pay attention to the WARNING statements They point out situations that can cause injury Pay attention to CAUTION statements They point out situations that can cause equipment damage TABLE OF CONTENTS SECTION 1 CIRCUIT DESCRIPTION 1 1 INTRODUCTION 1 2 DETAILED CIRCUIT DESCRIPTION 1 2 1 Transducer Signal Path 1 2 2 Display Communication 1 2 3 Front Panel Control 1 2 4 Muffle Control 1 2 5 Vacuum Control 1 2 6 Power Supply 1 2 7 Motor Drive Control SECTION 2 TROUBLESHOOTING 2 1 FACTORY REPAIR 2 2 BEFORE YOU START 2 2 1 Isolating a Problem 2 2 2 Understanding the Error Codes 2 2 3 Troubleshooting Digital Circuits 2 3 TROUBLESHOOTING GUIDES 2 3 1 Power Supply 2 3 2 Microprocessor 2 3 3 Peripheral Drive 2 3 4 Motor Drive
5. 16 character by 2 lines LCD module is controlled by the microprocessor via its Serial Peripheral Interface SPI port The display is updated every 0 5 sec or when a corresponding front panel key has been activated 1 2 2 3 LED Display The 10 status LED s are controlled by a serial input latched driver integrated circuit After the serial data is received the strobe signal latches this data The state of the LED s can only be changed by accepting new data 1 2 3 Front Panel Control 1 2 3 1 General Description The front panel switches are arranged in a 8x4 matrix The microprocessor scans the entire matrix every 50 msec by setting one column at a time to a logic 0 and 9415 then reading the rows Once contact closure has been detected this value is stored At the next scan the closure is compared with the stored value and ifa match has been established the command is carried out This prevents erroneous data due to contact bounce 1 2 4 Muffle Control 1 2 4 1 General Description The microprocessor U10 sends aserial digital signal to an octal peripheral driver U16 which in turn converts and latches it to parallel data This parallel data is then used to drive several peripheral devices See 5006 U16 13 is connected to an opto isolator U8 The isolator s output is connected to the gate of the muffle triac The muffle triac may be activated anytime during an ac cycle but once activated it can only be opened when
6. 3 4 1 Required Test Equipment 4 1 2 digit millivoltmeter Temperature calibrator Type K Pot adjustment tool Vacuum gage 0 760mm WARNING With covers removed dangerous voltage points may be exposed Contact with any of these points could cause serious injury CAUTION Observe antistatic procedures when touch ing circuit board components 3 4 2 Temperature Enter the setup mode Owner s Manual page12 and enter 960 C for Tcal Disconnect the muffle thermo couple from the control circuit board and connect the temperature calibrator on its place Set the output of the calibrator to 960 C Adjust R4 to read 960 C on the furnace display Instead of a calibrator a low output impedance mV source set to 38 8 mV can be used A 5 C calibration can be obtained without the tempera ture calibrator by performing the following sequence Leave the control thermocouple connected and adjust R4 to read 39 7mV at TP3 Adjust R3 to read 52mV at 3 4 3 Vacuum Enter the setup mode see Owner s Manual and enter the Vcal value for this particular location see 3 3 2 Disconnect the Vacuum hose from the transducer U6 on the control circuit board and connect its end to a standard reference vacuum gage Reconnect the other end from the gage to the vacuum transducer Run a vacuum cycle with a level setting of 10196 Pump stays on Compare the reading of the gage with the reading ofthe furnace display and adjust R22 un
7. GRN YEL EB e TRAY TUBING TU SOLENOID VALVE VPC only The TC wire positions are reversed on Rev 1 PCB s ROUTE WHT BLK WIRE THRU XFORMER 0 CM E x SE REAR VIEW DISPLAY PCB Ly MEMBRANE SWITCH 9628 2 16 3 1 SCOPE This section gives the procedures to be used for the calibration and specification verification of the CENTU RION The furnace specifications are given in the Owner amp Operator s Manual 3 2 FACTORY REPAIR NEY Dental International maintains a factory repair department for those customers not possessing the necessary personnel or test equipment to maintain the CENTURION If a unit is returned to the factory for calibration or repair a detailed description of the specific problem should be included to minimize turnaround time 3 3 ADJUSTMENT CALIBRATION 3 3 1 Temperature To calibrate the furnace or to verify its calibration by means of the silver coupon method refer to the owners manual However in most cases the temperature error at or near 960 C is known and this error can now be corrected by using the Tcal Setup feature Simply ask yourself What is the real muffle temperature when the display shows 960 C Subtract this value from 960 C and add it to the Tcal setting The following example should clearify this procedure further It is determined that a certain porcelain overfires for a given program cycle But since many other program cycles have similiar Hi Temp
8. Sec 2 4 7 for trouble shooting guides P SCREW 6 X 25 Pr n 5 5 7 4 Pinch tube PUMP Observe gage If VAC level holds then chamber leaks If VAC level drops then leak is in valves or gage Proceed to step 5 5 5 LINE CORD SOCKET 0 5 7 1 Remove 4 screws and pull out bracket 5 7 5 Pinch tube Observe gage If VAC level drops then gage leaks If VAC level holds then leak is in valves Replace valve kit Proceed to step 5 5 6 512 SOL 5 7 2 Pull vacuum and place in HOLD ay ig To Gage 5 7 6 Follow steps 5 1 1 5 1 3 of CONTROL DRAWER REMOVAL then disconnect valves wires from Control PCB and tubing from gage 5 7 3 Remove power cord from wall outlet 9631 5 9 VALVE KIT 9493074 a 12 y UA lt Ons 2 N GAGE G Ila 1L To 5 7 10 Route valve wires and tubing through cable guide and connect to Control PCB 5 7 7 Disconnect tubing from valve kit Remove valve kit from bracket by removing 2 screws 5 5 11 Mount bracket to base with 4 screws To Chamber 5 7 9 Reconnect tubing 9631 5 10 5 8 MOTOR VPC INTERVAC Tools Long 2 Phillips screwdriver 5 32 Allen wrench Large adjustable wrench 1 or 25 m
9. and a logical 0 low A stuck bit may not switch at all It may always be high always low or always between logic levels in an undefined state A stuck bit may also switch between high or low levels and an undefined state 2 3 TROUBLESHOOTING GUIDES Refer to table 2 1 for functional circuit guide information 2 3 1 Power Supply To determine a faulty power supply use table 2 3 To troubleshoot a faulty power supply use the procedures listed in table 2 4 If the desired results are obtained in each of the steps in table 2 4 replace D43 U9 or U7 as appropriate 2 3 2 Microprocessor Generally when the furnace is totally nonfunctional i e display is unintelligible no display random relay click ing no key response or the front panel LED s stay on at power up the problem is in the microprocessor section 9630 However before troubleshooting this section check the appropriate dedicated circuits for correct operation Detailed reading of the circuit description is also very helpful before attempting to find and correct a problem Use table 2 5 to troubleshoot the microprocessor 2 3 3 Peripheral Drive The peripheral driver U16 is accessed at every line voltage zero crossing 1 0 by the microprocessor U10 32 33 The logic state of the eight output drivers YO Y7 is latched into the shift register at time 10 on the high to low transition of SIOE Input data present at the Slinputis clocked into the shift re
10. and may also allow the user to gain greater insight into the CENTURION s versatility for particular applications The block diagram of the CENTURION is shown on page 2 6 The operational description that follows is separated into seven functional blocks Transducer Path consisting of the thermocouple vacuum transducer operational amplifier Multiplexer constant current source millivolt source A D converter and overtemperature protection circuit Display Communication consisting of the display con nector and display board assembly Front Panel Control consisting of the power ON OFF switch and membrane switch panel Muffle Control consisting of the peripheral driver opto triac driver muffle triac and relays K1 K2 Vacuum Control consisting of the peripheral driver solenoids and relay K3 Power Supply Refer to figure 2 1 Troubleshooting block diagram for a more detailed look at circuit block interaction Motor Drive Control Consisting of the motor drive 12VDC motor and connector 1 2 DETAILED CIRCUIT DESCRIPTION 1 2 1 Transducer Path 1 2 1 1 General Description All signal paths are filtered fed through an 8 channel multi plexer amplified and converted to a digital signal The microprocessor accesses this digital signal at regu lar time intervals and calculates the respective vari ables 1 2 1 2 Thermocouple The muffle temperature is derived from a Platinel Ther mocou
11. in conjunction with the schematics Section 2 8 Successful troubleshooting depends upon under standing the circuit operation within each functional block as well as the block relationships WARNING With covers removed dangerous voltage points may be exposed Contact with any of these points could cause serious injury The intent of this section is to provide the information to return the CENTURION to proper operation Informa tion is divided into two parts Part one contains the overall furnace troubleshooting block diagram figure 2 1 which is useful in isolating defective blocks within the furnace Part two consists of a series of circuit guides table 2 1 one for each block shown in figure 2 1 that provides settings and measurements for troubleshoot ing an individual block Also each circuit guide refer ences related schematics and circuit descriptions Inspectthe components wiring and circuit boards of the CENTURION for damage Finally ensure thatthe fuses are intact and the internal power supplies 12V and 5V are good 2 2 1 Isolating a problem To successfully troubleshoot this furnace the symp toms must firstbe identified the faulty block isolated the block analyzed and the defective component located and replaced To identify the symptoms use the front panel switches and measurement results from the Test Points For example if the motor is not responding to the key switch command are any other perip
12. panel surface without removing pencil marks VPC shown 5 13 6 Gently place membrane into front panel Use penciled corners to locate VPC shown CONTROL PCB MEMBRANE SWITCH 5 13 7 Connect ribbon connector VPC shown 9415 5 16 CENTURION SERVICE NOTES 9363037 rev E 9637
13. through all the ports When replacing a plastic fitting care must be taken not to cross thread Torque fittings to at least 12 in Ibs 1 5 N m 2 4 8 Chamber Leaks If it was determined in Sec 2 4 7 or Sec 5 4 5 that there is a chamber leak then the following procedure should be performed a A likely source for a vacuum leak in the chamber is due to an obstruction at the door O ring seal With a clean rag wipe away any material around the O ring b Next check that there are no obstructions which prevent the chamber from closing all the way Press the up then down keys If the chamber does not close entirely remove the door insulation and try again as the door insulation may have moved out of position c If the unit still does not pull vacuum press down on the top cover while in a VAC cycle after the pump turns on If vacuum still does not pull the leak is elsewhere in the chamber d Check the vacuum hose connections thermo couple seal muffle termination connections and the view window seal Check the tightness of the muffle termination connections as these can take a set after extended time at high temperatures Tighten to 12 15 105 1 5 N m 2 4 9 Reflective Window The reflective window has a very delicate hi tech reflec tive coating on the outer surface Any abrasive material or skin oils can cause permanent damage to this sur face If this surface should become dirty clean accord ing to t
14. transducer Go to 5 4 6 guides 5 4 6 Pinch tube ds Observe display If VAC level drops then transducer leaks If VAC level holds then leak is in valves o o S 5 4 2 Pull out valve assembl 5 4 3 Start a cycle on an unused program using the following recommended parameters LoT 200 C Rate 50 C mi 300 C 512 SUL Dry 0 00 M Hold 5 00 M Cool 0 00 M VAC 80 Pull 200 C Stop 400 C CONTROL PCB 5 4 8 Follow steps 5 1 1 through 5 1 3 of CON TROL DRAWER REMOVAL Disconnect valve wires and tubing from Control PCB 5 4 4 Pinch tube when pump LED turns off 9628 5 4 11 42 5 4 9 Route valve wires and tubing through cable guide and connect to Control PCB 5 4 10 Mount valve assembly to base 4 screws 9415 9 5 5 5 SOLENOID VALVES VPC Il VPQ VPM S N prefix ABV DBV ABT DBT ABW DBW Tools Phillips screwdriver 7 16 open end wrench Pliers 5 16 Nutdriver This procedure should be done if there is an excess vacuum leak in the system producing Err4 Err5 Err13 or Err14 Refer to Sec 2 4 7 for trouble shooting guides 5 5 4 Pinch tube Obse
15. values it is desired to lower the calibration rather then to reprogram every Hi Temp It is now estimated that a lowering of the Hi Temp by 5 C would eliminate the overfiring thus the muffle tempera ture ata display reading of 960 C is actually 965 C The new setup temperature Tcal is now found by the follow ing calculation Tcal Tcal 960 C 965 C or in this case Tcal Tcal 5 C If the Tcalis still at its factory setting of 960 C reprogram it to 955 C If it has been modified previously let s say to 950 C reprogram itto 945 C Ifthe porcelain underfires simply add the result obtained from the equation to the setup Tcal The limits for Tcal are 860 C to 1060 C 3 1 SECTION 3 ADJUSTMENTS CALIBRATION 3 3 2 Vacuum Since the atmospheric pressure varies from sea level to higher elavations and the vacuum transducer obtains absolute readings it is necessary to adjust the Vcal setup for a particular geographic location The factory setting is done for this location and determined to correspondto 710mm Hg This takes into consideration a strong vacuum pump For higher elevations the following adjustments for Vcal should be made For each 300m of additional elevation subtract 20mm from 710mm Add 20mm to the factory setting forasea level location Should a value be known which a particular vacuum pump is able to obtain at this location enter this value for Vcal For example a firing cycle with a VAC sett
16. 2 3 5 Analog Circuitry 2 3 6 Display Board 2 4 TROUBLESHOOTING COMPONENTS 2 2 2 4 1 Diode 2 4 2 Operational Amplifier 2 4 3 Triac 2 4 4 Capacitor 2 4 5 Logic Levels 2 4 6 Motor 2 4 7 Valves 2 4 8 Chamber Leaks 2 4 9 Reflective Window 2 5 ERROR CODES 2 6 BLOCK DIAGRAM 2 7 DIAGNOSTIC TABLES 2 8 SCHEMATICS 2 9 WIRING DIAGRAM SECTION 3 CALIBRATION 3 1 SCOPE 3 2 FACTORY REPAIR 3 3 ADJUSTMENT CALIBRATION 3 3 1 Temperature 3 3 2 Vacuum 3 3 3 Lift Drag Adjustment 3 4 CIRCUIT BOARD CALIBRATION 3 4 1 Required Test Equipment 3 4 2 Temperature 3 4 3 Vacuum 3 5 CONVERSIONS 3 5 1 Temperature 3 5 2 Vacuum 3 5 3 Pressure SECTION 4 SERVICE PARTS 4 1 ORDERING INSTRUCTIONS 4 2 1 VPC CONTROL DRAWER PARTS 4 3 VPM CONTROL DRAWER PARTS 4 4 MUFFLE amp VACUUM CHAMBER PARTS 4 4 4 5 VPC LIFT MECHANISM PARTS 4 6 VPM LIFT MECHANISM PARTS 4 7 VPC DOOR amp CABINET PARTS 4 8 VPM DOOR amp CABINET PARTS 4 9 VPC MOTOR amp VALVE PARTS 4 10 VPM VALVE PARTS SECTION 5 DISASSEMBLY REASSEMBLY 5 1 CONTROL DRAWER 5 2 MUFFLE 5 3 THERMOCOUPLE 5 4 SOLENOID VALVES VPC S N Prefix ABS DBS 5 5 SOLENOID VALVES VPC S N Prefix ABV DBV ABT DBT 1 1 INTRODUCTION 1 Denotes Particular Model Only The purpose of this section is to familiarize the user or service personnel with the circuit level operation of the CENTURION This knowledge is necessary to aid in troubleshooting of a unit failure
17. 52040 9492987 9492980 9352040 9493070 9492980 9352058 Pivot Linkage service Upper Pivot Arm service 9493066 9493067 9493066 9493067 9493066 9493067 9493064 Lower Pivot Arm service Friction Washer Door amp Cabinet Parts p 4 7 8 Top Enclosure Bottom Enclosure Column Cover 9493068 9492957 9492958 9492942 9493068 9492957 9492958 9492942 9493068 9492957 9492958 9492942 9493067 9901053 9493017 9492958 9493015 Door Door O Ring 9492885 9357071 9492885 9357071 9492885 9357071 9492885 9357071 Door Mounting Kit Ceramic Work Platform Motor amp Valves Parts p 4 9 10 Valve Kit Venturi Valve Kit 9492991 9493008 9492983 9492991 9493008 9493074 9492991 9493008 9493074 9493145 9492991 9493008 9493074 Motor Assy Line Cord USA 100 125V Line Cord EURO 200 250V Other Parts Assy Accy Kit Side Shelf 9492984 9390115 9390117 9492920 9492932 9492984 9390115 9390117 9493140 9492932 9492984 9390115 9390117 9493140 9492932 9390115 9390117 9493019 9492932 Side Shelf Ceramic Tray Hardware Kit Assorted Fasteners 9390017 9492988 9390017 9492988 9390017 9492988 9390017 9492988 Tool Kit Magnetic Log Cards pkg of 5 Box amp Supports 9492989 9492975 9493069 9492989 9492975 9493069 9492989 9492975 9493069 9492989 9492975 9493069 4 2 VPC CONTROL D
18. LINTERBAL ANCE 9352040 BALANCE SUPPORT 9628 4 5 4 6 VPM LIFT MECHANISM PARTS SNAP IN BUSHING 1 2 x 5 16 SHOULDER BOLT 9352053 2 UPPER SHOCK BRACKET 9493012 LOWER PIVOT ARM UPPER PIVOT 8499067 9493064 2 PL Lipper Pivot Arn REF BRONZE BUSHING 8320027 6 PL GAS SPRING 9352058 Rear Colunn Friction Washer 9901053 4 PL 2 PER SIDE BA 9628 4 6 4 7 VPC DOOR amp CABINET PARTS TOP ENCLOSURE 90528571 SCREW 38 x 22 DOOR O RING 852971 9450685 Ceramic Work Platform 0493008 De MIO 9459981 REAR HEATSHIELD 5452042 B VP 4 2 IN WASHER FID EXT ENCLOSURE 0492958 9628 4 8 VPM DOOR amp CABINET PARTS ENCLOSURE 9483017 SCREW 48 x 142 ABs SCREW 46 128 RING 93547 HANDL E 7 0490885 9157005 Ceramic Work 2 18 Platform 9403008 L Y C HATUIELD A T A a 4 P REAR HEATSHTELD 2 9493015 SCREW 46 32 X 1 2 8 x 38 WASHER FID EXT 9402058 9628 4 9 VPC MOTOR amp VALVE PARTS VALVE amp FITTINGS 9493074 X ABV ABT NEW 6 x 25 fo 10 32 50 6 x 25 Line Cord amp Strain Relief 100 125V SUCKET FUR 200 250V VALVE amp FITTINGS LINE CURD 100 125V 9390115 EU
19. Min TP4 50 55 mV stable 2mV C ambient increase typical U2 1 center Apprx 120mV stable TP6 1 3 mV U6 2 4 Same Voltage 2 5V Display Adjust to gage level Display Obtain previous gage N A No Err2 at pump turn on No Err2 at elevated temperatures Tighten TC wires Solenoid Approx 35 ohms each resistance TP2 See Table 2 3 Table 2 8 Analog Circuitry continued Results desired See Table 2 3 See Table 2 5 Tight fit No stuck bits digital low 90V 100V 2 400Hz U1 2 4 40 No stuck bits LED s turn off one by one Nite on See table 2 3 Front panel J2 4 LED Not open or shorted Life of Display Backlight dimmer with age Less than 40 C LCD lighter shade Table 2 9 Display Board 9628 2 8 Schematics 09 LM2575T 12 Feedback 1 Vunreg 15 30V 103 Vi nem 120 ac 1 1N5404 y s 9 Vout 12V 240V VOLTAGE C40 3 GND ON OFF 2250 2200uF i 120V 5 1N5404 RN12 A TP10 100K 2 LMSSSN Vunreg x 1 2200uF RN13 A 10K 4 H11AA1P RN12 D 8 LM358N een 10 msec 5 2 POWER SUPPLY V BROWN OUT DETECT Hi 8 3 msec eeepz 1 ZERO XING t 8 3msec 60Hz 5V UNDER VOLT 1 msec 50Hz 212 MC34064 5 5 RES GND TP 1 Zero Crossing 014 X24C16 4 000MHz C21 EEPROM MEMOR
20. RAWER PARTS CONTROL PCB ASSY ABS 0492978 100 125V BS 9492992 200 250V ABV ABT 9493143 100 1251 DBV DBT 9493144 200 250V 10 22 1 5 SCREW 46 32 38 FUSE 1A 9320071 2 9303015 BE EL TRAY ASSY 0492055 DISPLAY PLB ASSY ABS DB 9492979 PONER SWITCH ABU DBL ABV 9493142 9306021 MEMBRANE SWITCH 9354178 9628 4 2 4 3 VPM CONTROL DRAWER PARTS CONTROL PCB 9493071 100 125 9493072 200 250V SCREW 40 22 x 1 75 SCREW 6 32 x 3 8 FUSE 1A TRIAL 9320071 2 9303015 FUSE 154 9320063 FRONT BEZEL TRAY ASSY 9493073 VACUUM GAGE SERVICE 9493003 DISPLAY 9493009 PIMER SWITCH 930602 MEMBRANE SWITCH 9354189 9630 4 3 4 4 MUFFLE amp VACUUM CHAMBER PARTS 9492980 ASSY VJTJCJCC SCREW 16 x 25 COPPER TLBING SCREW 8 32 x 312 ELBOW FITTING WINDOW KIT vec MUFFLE ASSY FIBER 100 125V 9492976 200 250V 9492977 QUARTZ MUFFLE ASSY 100 125V 9493697 200 250V 9493698 RETAINING RING 9492902 TERMINATION KIT 9493062 9628 4 4 4 5 VPC LIFT MECHANISM PARTS 1 2 x 9 16 SHOULDER BOLT BRONZE BUSHING 11 PL 7 97 UPPER PIVOT ARM SERVICE 9493067 LOWER PIVOT ARM SERVICE 9493068 PIVOT LINKAGE SERVICE 9493060 ANCHOR PLATE 2 SCREW 10 32 172 CO
21. RO CORD 200 250V 9390117 MOTOR ASSY 9492984 4 9 1 VENTURI VALVE PARTS VENTURI VALVE KIT 9493145 X ABT UBT one valve only 9628 4 9 4 10 VPM VALVE PARTS VALVE KIT 9493074 SCREW fb x 25 PUMP SULKET Line Cord amp Strain Relief 00 125V SUCKET FOR 200 250V LINE CORD 100 1251 9390115 CORD 200 2501 9300117 9628 4 10 SECTION 5 DISASSEMBLY REASSEMBLY 5 1 CONTROL DRAWER Tools Phillips 2 screwdriver or 1 4 nut driver 5 1 3 Slide front panel up then out to remove tabs from bottom enclosure 9628 5 1 5 2 MUFFLE Tools Phillips screwdriver 2 short Pliers Set up Move to up position Allow to cool Note To bypass Err6 Press UP key while turning on power VPC only Caution Do not touch the quartz spiral during muffle replacement Handle on outer surface Disconnect terminals using pliers if needed amp remove muffle vacuum chamber Slide muffle and ring into chamber lining up guides 5 2 4 Turn furnace gently on it s side holding by column not top enclosure Loosen 3 screws and rotate ring 5 2 10 Rotate retaining ring into the locked position then tighten 3 screws 9628 5 2 5 3 THERMOCOUPLE Tools 3 4 wrench or adjustab
22. U18 A 2 1 25V U18 A 1 gt 2 5 V EEPROM read write error Program parameters entered during the idle mode are transferred and stored in a 16K bit Electrically Erasable Programmable Read Only Memory EEPROM device The serial data on U14 5 is monitored and any abnormal behavior from the devices specs is answered with an error code Press ENTER and check Data Clock train on U14 5 6 Replace device If Err8 occurs at power up the program number might be scrambled Reprogram EEPROM Refer to service notice N9335 1 in back of manual Note VPC Il and Intervac furnaces have program to reset EEPROM to factory preset settings On these furnaces to completely re program the EEPROM call program 59 press ESC andthen call program 159 The display will show EEPROM ENTER Press ENTER to reset TC input short reversed The control monitors the increase in temperature during the 0 C 100 C range If no increase in muffle tempera ture is detected during a 30 second period the power relays open and the Err code is dis played Check for correct TC polarity on circuit board Check for shorts on top of Thermocouple Over current Excess AC line current detected This error may also occur when a vacuum pump draws excessive current at turn on elec trical noise Turn the furnace off then on again Check the first two digits of the second line during TEST 85 TO 90 indicates high line voltage greater t
23. Y 10 10K PDO RDI PD1 TDO PD2 MISO PD3 MOSI DATA CLOCK DIS ENA LED ENA iig MC68HC705C8S RS GND U1 10 U1 11 MICROCOMPUTER and SUPPORT CIRCUITRY 9628 2 11 OVER TMP 1 p25 k JYELL1 91 14051 2 130mV TEMP MUFFLE OPEN TC JRED1 gt Platinel 14 110mV 5V R21 8 R7 10M 36 5K 010 15 9 RN5 E 100K RN2 E 1 23V 10K Current Source OUT GND Disch TRIGG 1 3 V 100K C6 220pF TEMPERATURE MEASUREMENT 5003 01 13 14 Voz2 V2 V1 Vo 72mV 710mm Vacuum Transducer VACUUM MEASUREMENT 5004 9310 2 12 LM358N 7 TP8 U10 30 Overcurrent Detect Vout peak TLC27M RN7 D 8 7 Cut for 230V CURRENT SENSE 5005 TRANSFORMER LINE PUMP PLUG SOCKET LINE BLK T PT2 e MUFFLE PT4 GATE MUFFLE RELAY VACUUM PUMP HEATSINK 12V 7 1N4004 1N4004 aw TRIAC TO CURRENT LOOP MT2 U8 6 V RN13 B 10K ss is 3 4 C30 E x MOC3041 R24 100 PT5 SOL2 TuF RN13 E 10K UCN5821 PERIPHERAL CONTROL 010 10 010 6 010 536 1 gt 2 STOP JAM DETECT MOTOR CONTROL 5007 DISPLAY BOARD VPC 9310 2 14 DISPLAY BOARD VPM 9628 2 15 2 9 WIRING DIAGRAM SOL 3 vec PUMP SOCKET Ed only SL 1 512 CORD 21 5 THERMUCOUPLE 220 240V f RECEPTACLE MOTOR TO MUFFLE RNE CABINET GND TAN
24. ane keys Stall current U13 15 JYELL1 U1 13 3 U1 9 10 11 TP5 7 2 TP3 TP4 D1 K TPS Results desired No stuck bits DS23 24 are On No Error codes Display OK Not shorted or open digital high digital high Table 2 6 Peripheral Drive Circuit Results desired 12 V DS20 21 On DS21 off DS20 on DS20 off DS21 on Not shorted or open digital high Other keys respond gt 550 mA at up or down High to low at up or down Table 2 7 Motor Drive Circuit Results desired TC yellow connected Same mV 1 40 No stuck bits same frequency 1 2 See Table 2 3 39 7mV stable 50 55mV stable 1 23V stable Stable frequency No sweeping Table 2 8 Analog Circuitry 9628 Fault Setup Temperature drift Hi T 960 C difficult to to calibrate Hold 20 00M VAC 0 Vacuum readout too Furnace in idle high or too low VAC calibration See 3 4 2 VAC cycle 101 level reading Err2 during VAC cycle but TC is good Change Pump oil or pump Turn furnace off Fault Setup LCD dots are all on or off at power up Furnace in idle No backlight Furnace in idle No LED s light up Perform power up N A One LED does not come on Turn furnace off LCD display dim N A LCD display dark Turn furnace off Turn furnace on 2 10 Temperature on panel Temperature on panel Check Results desired JYELL1 39 40mV stable 1 2mV increase during first 5
25. d in parallel with the capacitor under test and observing the resulting effect Leaking capacitors will often have a decreased voltage across their terminals 2 4 5 Logic levels Microprocessor High 3 5 5 0V Low 0 0 1 0V 7415 High 2 0 5 0V Low 0 0 0 5V 4XXX High 3 5 5 0V Low 0 0 1 5V 9628 2 2 2 4 6 Motor If Err 15 occurs frequently it is an indication that the motor might be producing excessive current spikes This can occur as the brushes become worn Refer to section 2 3 4 to determine whether both of the motor LED s are on or off when this message occurs Objects placed on top of the cabinet can cause the motor to work harder thus producing this error message Remove any objects placed on the top enclosure Err 15 can also occur if the valves release slowly Run a cycle without vacuum to determine if the error still occurs If so check for obstructions in one of the tubing lines 2 4 7 Valves Much of the information needed for troubleshooting the valves is in Sec 5 4 It is important to note that vacuum leaks may not always be an indication of a bad valve Before replacing a valve isolate both sides of the valve as described in Sec 5 4 to verify that the leak is indeed in the valve and not in the chamber or the vacuum transducer Indications of a leaky valve can be Err 4 or Err 15 It may be possible to clean contaminants from the valve by blowing high pressure gt 50 air
26. er This provides all necessary functions for a complete closed loop system A two wire cable connects the motor to the 1 Amp H bridge switch on the The microprocessor U10 activates the H switch through two input pins If both are low the motor will turn in one direction if both are high the motor turns in the opposite direction A third pin sends a signal from the motor controller driver 1 to the microprocessor when the motor has stalled The microprocessor then determines ifthe motor has travelled the full travel or if the motor has been stalled before the end of normal travel Ifthe motor has been stalled the microprocessor displays an Err 15 code 9348 1 2 2 1 FACTORY REPAIR Ney Dental International maintains a factory repair de partment for those customers not possessing the nec essary personnel or test equipment to maintain the CENTURION If a unit is returned to the factory for calibration or repair adetailed description of the specific problem should be attached to minimize turnaround time Call factory for RMA number before shipping 2 2 BEFORE YOU START Since no troubleshooting guide can possibly cover all the potential problems the aim of this guide is to give a methodology which if applied consistently will lead to the problem area Therefore itis necessary to familiarize yourself with the CENTURION by reviewing the func tional description and the detailed circuit description Section 1
27. et to high Setup For each 500m elevation subtract 30mm from 740mm Pump lost its performance Hose connections Fittings Check for kinked hoses loose muffle terminals See Err4 Open muffle Low or no AC current This error code will only be displayed at power up If the muffle wire should open during idle mode the display will eventually show ERR alow temperature Turn the furnace off then on again to verify this diagnostic Otherwise check Power relays click on at power up Line Voltage within specifications Muffle resistance present Continuous wiring MT2 to MT1 lt 2Vac on muffle triac 9 gt 20 mV U1 5 U1 3 TP9 reading To operate the motor under an Err6 condition Turn furnace off Hold 1 key down and turn on Wait for relay to click and release key Use muffle movement key Low Line Voltage When the line voltage drops below the required operating level for the microprocessor and its peripherals the processor receives a signal from U18 A 1 and terminates its normal opera tion This error is most likely displayed after power outages or the power line is downloaded by other high power equipment Turn the furnace off then on again TP10 gt 15V 5V ripple Check the first two digits of the second line during test 9420 Err 8 Err 9 Err 12 45 to 50 indicates low line voltage less than 80 of rated line voltage U9 1 x 1 TP10
28. f Shipment VPC VPCI INTERVAC VPM ABS DBS ABV ABW ABU DBU ABT DBT DBV DBW This information is needed to determine if the product is under warranty and to help us in tracking failures so that corrective action can be taken to prevent future problems SERIAL NUMBERS Control Drawer Parts p 4 2 3 Membrane Switch Triac Display PCB Assy Control PCB Assy 100 125V 9354178 9303015 9493142 9493143 9354178 9303015 9493142 9493143 9354178 9303015 9493142 9493143 9354189 9303015 9493009 9493071 Control PCB Assy 200 250V Power Switch 9493144 9306021 9493144 9306021 9493144 9306021 9493072 9306021 Fuse 15A 250V Fuse 1A 250V 9320063 9320071 9320063 9320071 9320063 9320071 9320063 9320071 Front Bezel Tray Vacuum Gage service 9492985 Muffle amp Vacuum Chamber Parts p 4 4 Muffle service 100 125V Muffle service 200 250V 9492976 9492977 9492985 9492976 9492977 9492985 9492976 9492977 9493073 9493063 9492976 9492977 Quartz muffle 100 125V 9493697 9493698 9493697 9493698 9493697 9493698 9493697 9493698 Quartz muffle 200 250V Muffle Retaining Ring Muffle Termination Kit 9492902 9493062 9492902 9493062 9492902 9493062 9492902 9493062 Vacuum Window Kit Thermocouple Lift Mechanism Parts p 4 5 6 Counterbalance Gas Spring 9492987 9492980 9352040 9492987 9492980 93
29. gh vacuum or no vacuum Err4 or Err 5 5 6 1 Check that the vacuum tubes are connected for the Intervac pump see operation manual 5 6 2 Check compressor performance Minimum air requirements for the pump are 80 psi and 4 cfm Most 1 5 HP compressors will handle these requirements AIR MUST BE DRY FILTERED 5 6 3 Check the Muffler filter to see if it has be come clogged with dirt If so remove and clean If an ultrasonic cleaner is available this will work best 5 6 5 Follow steps 5 5 1 and 5 5 2 of valve servicing procedure 5 6 6 Check for kinks or restrictions in tubes any restrictions can affect pump perfor mance 5 6 7 If these steps are ineffective in correcting the problem then replace Venturi Vaccum pump assy First remove muffler filter from end of tube Venturi Valve Kit 9493145 X ABT DBT E 5 2 3 5 6 9 Follow steps 5 1 1 5 1 3 of CONTROL DRAWER REMOVAL then disconnect SOL 3 valve wires from Control PCB NOTE TUBING ROUTING 5 6 10 Reverse steps 5 6 9 thruough 5 6 7 to replace with new valve kit NOTE TUBE ROUTING 9628 5 8 5 7 SOLENOID VALVES VPM Tools Phillips screwdriver 7 16 open end wrench Pliers 5 16 Nutdriver This procedure should be done if there is an excess vacuum leak in the system producing Err4 Err5 Err13 or Err14 Refer to
30. gister on the high to low transition of SCLK Use table 2 6 to troubleshoot the peripheral driver 2 3 4 Motor Drive The motor driver U13 is accessed by the microproces sor to lift or lower the muffle Two LED s are connected across the internal power H switch to indicate its state When both LED s are either on or off the motor is deactivated If one of the LED s is on the motor is activated U13 15 provides a feedback to the micropro cessor to indicate an overcurrent condition which is set at approximately 450mA by resistor R26 Use table 2 7 to troubleshoot the motor driver 2 3 5 Analog Circuitry The reference voltages used to control temperature and compare voltage signals are derived from the output of 07 2 5V 09 and D1 See section 2 4 for trouble shooting individual components Use table 2 8 to troubleshoot the analog circuitry 2 3 6 Display Board Serial data present on the input of U1 2 and U2 2 is transfered to the shift register on the logic O to logic 1 transition of the Clock input pulse Information present at any register of U1 is transferred to its respective latch when the Strobe is high U1 4 A serial to parallel conversion takes place As long as the Strobe is held high 1 the latches will accept new data The LCD display module will accept valid data on DO D7 when the Enable J1 6 goes from a high to low transition Use table 2 9 to troubleshoot the display circuit board
31. gram values Note VPC Il and Intervac furnaces have a program to reset EEPROM to factory preset settings See Err8 gt gt 40 mV gt gt 50 Change PCB if problem persists Tmax Over Temp The controller monitored a temperature above Tmax 20 C This could mean The Tmax was set up too low for this program The destination temperature is relatively low compared to the programmed heat rate eg too much temperature overshoot No VACUUM After the start of a vacuum pump request the controller checkfor a vacuum level of atleast 40 mm before the Vac Strt LED is turned off The absence of this reading during a specified time will generate an audible warning signal before the cycle is aborted Check all vacuum hose connections and operation of the vacuum pump plug into outlet to check Otherwise check TP6 gt 50 mV at medium vacuum level 5 7 gt 50 kHz at medium vacuum level Remove U10 and ground pins 14 15 pin 13 to pin 40 5V TP6 Volts at U1 14 15 U1 3 U1 is OK Check U6 see Schematic 5 1 1 Err 5 Err 6 Err 7 2 4 Low VAC The controller uses the Setup Vac Cal constant to calculate the programmed vacuum level It tries to reach this level and will stop pumping when no more increase in vacuum can be detected If this level cannot be reached the processor checks to see if the vacuum level is at least within 100 mm of the requested value VAC calibration s
32. han 120 of rated line voltage Check muffle resistance Remove U10 uP U15 A 2 1 25 U15 A 1 lt 5 2 5 Err 13 Err 14 Err 15 Err 16 Err 17 Err 18 Err 19 U17 B 5 7V TP8 gt 2 5V Solenoid 2 disconnected or open or Solenoid 1 disconnected or open check solenoid resistance 30 40 ohms Check crimp connections Check solenoid continuity with ohmmeter Test with a 10K ohm resistor across J4 J7 DS23 or DS24 should be on Check other outputs of U16 Sonar Check 12V D46 47 48 cathode Motor jam This error code is called whenever the muffle is requested to goto its first or second dry position and exceeds 12 seconds of travel Mechanical obstruction Motor current 500 mA Slow VAC release Muffle relay open Pump relay open Check 12 V D44 D45 Cathode to ground Check resistance of relay coils Triac driver input short Check U8 1 2 diode U8 2 shorted to ground No line frequency detected Check TP1 100 or 120 Hz pulse train Remove Power U11 1 2 diode check 2 R41 resistance check 9628 2 6 Block Diagram 35ojg Buljooysajqnes 2 Biy 5 IN 5143 GS AV SK a ce 184 Lod 3d pene E MAM 031 53 12 X 91 01 WIS 22 4 1 4 1905 I 25 55 JA KLON 413 4 104107
33. he following instructions Allow the furnace to cool to below 100 degrees C Cleaning should be done with deionized or distilled water and optical tissue CAUTION Ordinary tissue may contain wood fiber which can scratch the window If the window must be replaced because of damage or a leak as described in section 2 4 8 use the following procedure Disconnect power cord from wall outlet Remove the four 4 top cover screws and lift off top cover see sec 5 3 3 Remove retaining ring P N 9352044 sec 4 2 Remove window If stuck remove muffle see Sec 5 2 and knock out window from the inside Remove old O ring and clean out O ring groove Replace window O ring and retaining ring Make sure that retaining ring is fully installed Replace top cover and four 4 screws 9628 2 3 2 5 ERROR CODES NOTE xxx references do not apply to the VPC Err 1 Err 2 Err Err 4 furnace Muffle Over Temperature The controller monitored a temperature above 1220 C This could mean a faulty thermocouple mV reading too high or an erratic thermo couple performance the temperature readout is not stable at elevated temperatures Open TC Detected To check for open TC turn power to furnace off and short TC input terminals Turn power back on IfERR2disappears then replace TC Other possible causes Vac pump noise may have reprogrammed Setup parameters Check calibration param eters and pro
34. heral controls defective or not responding 2 1 SECTION 2 TROUBLESHOOTING Once the symptom is identified use figure 2 1 to isolate the circuit block After the block is isolated refer to the appropriate functional circuit guide table 2 1 The circuit guide provides some but not necessarily all of the possible failure modes for a particular circuit Where applicable a furnace setup procedure is given to help isolate the problem for a particular failure mode Paragraph 2 4 gives component troubleshooting infor mation 2 2 2 Understanding the error codes The microprocessor of the CENTURION constantly checks for proper circuit operation If it detects a faulty signal an error code will be displayed on the second line of the display In some cases a program cycle will be aborted and the muffle travels to its up position All peripherals will be disabled In orderto troubleshoot the furnace must be turned off then on again 2 2 3 Troubleshooting digital circuits Most of the digital circuits in this furnace are dynamic Even with no change made to the frontpanel keys internal circuits are running and lines are changing states This makes troubleshooting difficult without the use of powerful tools There is however a technique using an oscilloscope which will usually helps isolate an abnormal signal The basis for this technique is looking for stuck bits A normal digital signal will switch between a logical 1 high
35. ing electronic components 5 11 1 Follow steps 5 1 1 through 5 1 3 of CONTROL DRAWER REMOVAL 5 11 2 Disconnect wires from power switch DISPLAY PCB VUA 5 11 3 Disconnect ribbon connectors 5 11 4 Remove wires from relays K1 K2 and K3 using caution not to damage relays VPC ONLY 5 11 10 Secure 4 screws 5 11 11 Wire according to wiring diagram Make sure wires pass through cable clamps as shown and switch wires mount to left side of switch 5 11 5 Disconnect MOTOR VPO SOL1 SOL2 SOL 3 YEL RED wires and Vacuum hose VPC 9415 5 14 5 12 POWER SWITCH Tools Slotted screwdriver 5 12 1 Follow steps 5 1 1 through 5 1 3 of CONTROL DRAWER REMOVAL 5 12 5 Connect switch wires to side shown 5 12 3 Remove switch by pressing in tabs 5 12 4 Press in new switch 9628 5 15 5 13 MEMBRANE SWITCH Tools Phillips screwdriver or 1 4 nut driver Knife of other sharp edged device Fine point pencil 5 13 1 Follow steps 5 1 1 through 5 1 3 of CONTROL DRAWER REMOVAL CONTROL PCB MEMBRANE SWITCH 5 13 2 Disconnect ribbon cable 5 13 3 Pencil fine outline around two upper corners VPC shown ur 5 13 4 Peel off membrane switch Use knife if needed 5 13 5 Clean front
36. ing of 101 showed a maximum vacuum of 680mm on the display Enter the setup mode Owner s Manual and program the new Vcal value This new Vcal value represents the maximum value 100 the vacuum pump is able to obtain at this location If the VAC level should be changed to 50 the pump would stop at a display reading of 340mm 3 3 3 Lift Drag Adjustment VPM only The lift drag force is controlled by a set of friction washers on each of the upper pivot arms see fig 4 4 2 A wave spring should maintain a relatiely constant force even after severalthousand cycles the drag becomes too stiff toohardto open and close furnace ortoo loose muffle won t stay in pre dry or up positions an adjust ment can be made using the following procedure Tools required Phillips screwdriver 5 32 allen wrench 7 16 open end wrench Uplug the furnace from the wall outlet Remove the four 4 screws on the top enclosure Loosen the lock nuts on both sides of the rear column Turn the allen head screws on the upper inside of the column either clockwise to tighten or counterclock wise to loosen the drag force Note Equal adjust ment should be made on each side Turn screws only 1 6 of a revolution at a time when making adjustment Tighten lock nut while holding screw to prevent from rotating 9628 3 4 CIRCUIT BOARD CALIBRATION Calibration of the CENTURION circuit board is per formed in two steps Software and hardware
37. le wrench 3 16 nut driver 2 Phillips screwdriver Caution Muffle must be in down position to prevent damage to lift mechanism 5 3 1 VPC only If muffle is in up position bypass Err2 using the following steps Follow steps 5 1 1 through 5 1 3 of CONTROL 5 325 Remove thermocouple use 3 4 wrench while DRAWER REMOVAL supporting chamber Place jumper wire between red and yellow thermocouple connections on CONTROL PCB Slide in control drawer Plug in power cord Turn on power to furnace Press down key Turn off power and remove line cord and jumper wire Install CONTROL DRAWER sec 5 1 1 to 5 1 3 Qn l gt 3 5 3 2 Disconnect power cord from wall 5 3 6 Replace with new thermocouple Torque to maximum of 80 in lbs 9 N m EL 5 3 3 Remove 4 top cover screws and lift top cover off unit 5 3 8 Install cover and 4 top screws 5 3 4 Remove 2 nuts and lift off wires 9629 5 3 5 4 SOLENOID VALVES VPC S N prefix ABS DBS Tools Phillips screwdriver 7 16 open end wrench Pliers 5 16 Nutdriver Q we 10909 5 4 5 Observe display This procedure should be done if there is an excess If level holds then chamber leaks sec 2 4 7 vacuum leak in the system producing Err4 and If VAC level drops then leak is in valve s hose Err5 Refer to Sec 2 4 7 for troubleshooting or
38. m 5 8 4 Remove this screw from rear 5 8 5 Remove shoulder bolt and push linkage away from block Unloading the motor by lifting up and down on the chamber may help 5 8 6 Rotate drive block into horizontal position with large adjustable wrench 5 8 7 Remove motor from bracket 4 screws 5 8 8 Disconnect motor wires 5 8 9 Install new motor by reversing Steps 5 8 8 through 5 8 3 Torque all screws to 25 30 in Ib 8 N m 9628 5 9 TRIAC Tools Phillips screwdriver 1 4 nut driver 5 9 1 Follow steps 5 1 1 through 5 1 3 of CONTROL DRAWER REMOVAL 5 9 2 Disconnect wires from triac 5 9 5 Connect wires to triac according to Wiring Diagram page 2 16 Make sure connections are tight 5 9 3 Remove 2 nuts 5 9 4 Replace with new triac 9630 5 12 5 10 DISPLAY BOARD Tools Phillips screwdriver CAUTION Use proper ESD grounding techniques when handling electronic components 5 10 1 Follow steps 5 1 1 though 5 1 3 of CON TROL DRAWER REMOVAL 5 10 5 Connect grey ribbon connector 5 10 6 Reassemble Control Module 5 10 3 Remove from snap on standoffs 5 10 4 Replace with new Display PCB 9415 9 13 5 11 CONTROL BOARD Tools Phillips screwdriver Slotted screwdriver Needle nose pliers 5 11 6 Disconnect wires from triac CAUTION Use proper ESD grounding techniques when handl
39. ple type K which generates an output of up to 50mV This signal is compared with a maximum allow abletemperature signalto produce an error code in case of missing thermocouple outputs 1 1 SECTION 1 CIRCUIT DESCRIPTION 1 2 1 3 Reference Voltage A reference voltage path is obtained from a reference diode which is adjusted to obtain a temperature reading of 960 C 1 2 1 4 Cold Junction Compensation To reduce the Seebeck effect typically associated with thermocouple connections a constant current source is configured as a thermometer to produce a 0 2mV C change at its output 1 2 1 5 Vacuum Transducer The vacuum inside the muffle is sensed by a pressure transducer which outputs a differential voltage 1 2 1 6 Current Transformer The muffle ac current is converted to millivolts by a current to voltage transformer The voltage is then rectified and its magnitude properly divided This signal is compared with a maximum allowable current signal to produce an error code in case of extremely high current draws due to excessive line voltages or reduced muffle resistances 1 2 2 Display Communication 1 2 2 1 General Description The display board converts serial data to 8 bit parallel data Each byte transferred is either a command or a data byte depending on the state of the two control bits HS and E DIS ENA The LED s are accessed by two control bits strobed and LED ENA see schematic S009 1 2 2 2 LCD Display The
40. rve gage If VAC level holds then chamber leaks If VAC level drops then leak is in valves or gage Proceed to step 5 5 6 VALVE KIT 9493074 PINCH ES Be et 5 5 5 Pinch tube Observe display If VAC level drops then transducer leaks If VAC level holds then leak is in valves 5 5 2 Pull out valve assembly 5 5 3 Start a cycle on an unused program using the following recommended parameters LoT 200 C Rate 50 C min 300 C Dry 0 00 M Hold 5 00 M Cool 0 00 M VAC 80 Pull 200 C Stop 400 C 572 SOL Remove wires JD MOTOR O emove tube 5 5 7 Follow steps 5 1 1 5 1 3 of CONTROL DRAWER REMOVAL then disconnect valve wires and tubing from Control PCB 9631 5 6 VALVE KIT 9493074 SUL2 MILI Tranducer 5 5 11 Route valve wires and tubing thru cable guide and connect to Control PCB 5 5 8 Remove valve kit from bracket by removing 2 screws 9 5 9 Replace with new valve kit 5 5 12 Mount bracket to base with 4 screws To Chamber 5 5 10 Replace tubing 9631 5 7 5 6 SOLENOID VALVES INTERVAC Tools Phillips screwdriver 5 16 Nutdriver This procedure should be done if the internal venturi vacuum pump is not pulling high enou
41. the ac sine wave passes through 0 volts U10 accesses U16 0 5 msec before zero crossing to turn the triac off At this time a value calculated by the control routine determines how much time should elapse before the triac is turned on again To ensure proper operation and to prevent runaway conditions the outputs of U16 are read via the serial out port U16 9 1 2 5 Vacuum Control 1 2 5 1 General Description VPC The microprocessor 010 sends aserial digital signal to an octal peripheral driver U16 which in turn converts and latches it to parallel data This parallel data is then used to drive several peripheral devices See S006 U16 2 and U16 3 are connected to 12V dc normally closed solenoids which in turn control the flow of vacuum At the command to achieve vacuum in the muffle sole noid 1 is openedto allow passage to the muffle and relay K3 is closed to activate the vacuum pump Once the desired level of vacuum has been reached solenoid 1 closes and is deactivated To release the vacuum from the muffle solenoid 2 is opened U10 determines the time for solenoid 2 to be deactivated again once it can no longer detect a vacuum With Intervac units operation is the same except that the third solenoid SOL 3 is also opened when the command to pull vacuum is issued 1 2 5 2 General Description VPM Vacuum is controlled manually through a series of 3 membrane keys on the control panel These keys may be activated at any
42. til both readings are the same Note if a reference gage is not available use best estimate If it was necessary to turn R22 more than 2 turns abort the cycle and check the calibration by repeating this procedure Vacuum Calibration using Software Program 147 will automatically place the control into a 10196 Vac cycle At Enter the muffle closes and the vacuumis pulled until the control cannot detect anymore Vac increase 3 2 At this time the display prompts The operator can now key in a new value taken from a second reference gage or their best estimate At Enter the cycle is aborted 3 5 CONVERSIONS 3 5 1 Temperature 32 1 8 F 1 8 x C 32 F The 32 F number is not used in rate conversions 3 5 1 1 Example If temperature is 50 C the rate in F would be 1 8 x 50 C 90 F 3 5 2 Vacuum 1 in inch 25 4mm 100 x Desired vacuum level Vcal level in Setup 3 5 3 Pressure PSI kPa x 14504 PSI Atmospheres x 14 696 PSI kg m x 0 0014223 PSI Kg cm x 14 223 9628 SECTION 4 SERVICE PARTS 4 1 ORDERING INSTRUCTIONS To order parts select the part number required from the exploded view drawings in section 4 2 1 through section 4 6 2 When ordering parts please have the following information available 1 Serial Number of Furnace 2 Date Purchased 3 Where Purchased 4 Symptom of Failure 5 Part Number of replacement part 6 Preferred Method o
43. time Start Vac Hold Vac Release Vac The solenoids are actuated as described above in Sec 1 2 5 1 1 2 6 Power Supply 1 2 6 1 General Description Two DC power supply voltages are generated on the control circuit board 12V and 5V These voltages generated either from 115Vac or 230Vac 1 2 6 2 12V Power Supply Refer to schematic S001 The transformer T1 provides an AC voltage with a ground referenced center tap This voltage is rectified by diodes D41 and D42 and filtered by capacitor C40 This provides unregulated positive DC voltage for the switching regulator U9 The capacitor C42 protects against high voltage transients on the AC line that couple into the transformer secondary The output U9 2 is a pulse train with a period T of typically 19 2usec The catch diode D43 is a Schottky device which provides a return path for the load current when the output switch is off Inductor L2 and capacitor C46 filter and stabilize the 12V regulated DC voltage 1 2 6 3 5V Power Supply Refer to schematic 5001 page 2 11 DC voltage from the output of U9 is used by the 5V linear regulator U7 to generate the 5V The capacitor C48 provides addi tional filtering The constant current source U2 as wellas the 1 23V reference diode D1 generate their outputs from this supply 1 2 7 Motor Drive Control 1 2 7 1 General Description VPC The 12VDC motor which moves the muffle vertically is controlled by a 16 pin motor controller driv
Download Pdf Manuals
Related Search