Milestone MLS1200 pyro ashing module service manual
Contents
1. j R o B imm As Hn di E E O B p 3 85 5883 ETE ETA 43 44 9 ERROR MESSAGES In case the operator has any difficulties with the control terminal e g is in a sub menu and does not know how to come out of it the basic rule is to push the STOP Key to go back to the Main Menu Switching ON OFF the unit will cause resetting and going back to Main menu Work programs remain unaltered This chapter will list the most common error messages 1 DOOR NOT CLOSED As an added safety the magnetrons are provided with overheating thermal safety switch In the remote event of thermal overheating the following will appear CONTINUE CLOSE DOOR ABORT STOP If this error message is not due to the door interrupt the program and check if for example the cavity is empty After cooling the unit can be again operated regulary 2 FATAL ERROR RAM The unit is provided with a Lithium battery to save the storage in memory of working programs If the following message appears FATAL ERROR RAM check ram or battery It is supposed that the battery is exhausted and the operator has to call for immediate service Otherwise there may be modifications in the stored programs when the power is off The unit itself for the rest is ready for use After the error message press the STOP key and under EDIT O delete2. E Picture 5 Back view of MLS 1200 PYRO 24 1 Power supply 220 and 164 T fuse 2 interface board for 240 Remote Control 3 Radiofrequency filter RLC 4 Toroidal transformer 5 Cooling fan 6 Relays board 7 Microwave diffuser motor 8 Power board for Magnetron 9 Power supply board 10 ATC 300 Electronic board and Display Picture 6 Over view of MLS 1200 PYRO 25 Picture 7 below shows all the parts included the complete muffle kit p n 50075 ip efi WAS pA IQQ ES VEUG ERAN AE TEE ppap e TA 4 Miror pe br OP bin Ap nod eat 7 Boke De 2 e HX ERN e 3 MATE NEA er 1 iv perta ti e AES c 5 i MIS e A ads ra Fat E uve Pos di d a Picture 7 You can easily recognize all the items with their exact part number in the Figure 1 next page 26 TOP PLATE P N 50053 CERAMIC SUPPORT CERAMIC SUPPORT BACK LEFT BACK RIGHT P N 50054 P N 50055 HONEY COMB CERAMIC STOPPER P N 50046 MUFFLE FURNACE CERAMIC SUPPORT i PA oor THERMOCOUPLE CERAMIC SUPPORT 50056 PROTECTION TUBE FRONT RIGHT P N 50064 P N 50057 PLATE HOLDER OF HEATING ELEMENT P N 50058 FRONT FRAME P N 50059 A MUFFLE DOOR P N 50060 BASEMENT P N 50123 Figura 1 Top view of the complete muffle kit 50075 27 WARNING BEFORE USING REMOVE THE PLASTIC DISC PLACED ON THE CEILING OF THE WORKIN
3. the M240 Control Terminal and check all connections between CPU power supply and display D If after these checks A B and C the pro blem still remains replace in sequence Interface board 90 pins connection cable CPU board Display board A Open the M240 Control Terminal and check the connection between the key board and CPU B Heplace EPROM C Re initialize the EPROM by switching on the MAIN SWITCH and simultaneously push the STOP key on the M240 key board A Replace the EPROM B Initialize the new EPROM push simulta neously MAIN SWITCH and STOP TASTE on M240 Control Terminal C Replace the CPU board A Check the 50 pins connecting cable some pins may be bent or broken some cables of the 50 pin connector male or female may be unsoldered or detached or interrupted connection between PYHO unit interfa ce board and M240 Control Terminal may be loose carefully fasten the screws in the connecting plugs Check any short circuit on the interface board C Adjust the potentiometer T2 on the CPU board see chapter 7 10 TROUBLESHOOTING LIST PROBLEM Difficulties in switching on the M240 Control Terminal display dark or fully ligh tened or crossed by vertical and horizona tal lines Some keys on the M240 keyboard do not allow data input into the program Independent block of working program with return to the main menu The working program presents param
4. O 39 Figure7 Power board side view of components 40 8 Tisza 2 40 SFH 601 2 1093 r3 1 e a 4 gt B2x85C1 On z Dl z ATN 22 12 V Command Inlet 1 ST10 helays board 2 connected with 1 3 ST10 Relays board 220 4 ST1 6 5 511 220 Y DOOR SWITCH 7 door switch 8 door switch 9 not used 220 V Exit Trafo 10 not used 11 N High voltage transformer not used 12 L1 High voltage transformer Figure 8 Electric diagram of Power board eu x arem Apt TR 16 5 1 772 3 41 interface Connections on 240 Remote Control Prirder Centronics PE Balance 5230 2 x Xe Backview PC Connection RS 232 1 PC Connection PC Cable 1 2 MW 2000 2 Tx 3 4 5 GND 6 J20 7 8 9 Balance Connection RS 232 COM2 Balance Connection Balance Cable white 1 2 T 3 4 BTR 58 G 6 J19 7 8 9 Analog output Connection 7 GNDA GNDA analog ground 2 TP GND digital ground 38 Ti 4 Pressure AND 6 ANDA T2 external temperature 1 7 14 8 AYB 42 12 external temperature control catibration D A Power P9 Props 112 Figure 9 CPU cara top view of the components Figure 10 CPU card top view of the components sem ac HB cm WC HERS 8888 5 888 p 4588
5. Remove the polypropylene fixing screw located on the leftside of the Remote Control Unscrew the 2 screws located on the front and the 4 screws located on the rear side of the 240 Remote Control Remove the cover by raising the front and pushing towards to the back 1 Eprom 2 Ham 3 Microprocessor 4 Back up Battery 5 Buzzer 6 Contrast Regulation by potentiometer Picture 2 Notez The C P U Board is located Inside the Remote Control 240 21 Left safety switch is activated by lowering the door handle Left safety switch is activated by opening the door Fan cooling for nigh voltage circuit Door handle for opening closing Hole for quartz tube introduction only for Pyro Sulphate Ashing system with SAM35 C Picture 3 Left side view of MLS 1200 PYRO 22 1 Right safety switch is activated by lowering the door handle 2 Right safety switch is activated by opening the door 3 Front panel with acid resistant coating 4 Fan exhaust system Es ei TX ds x 2 iz 2 Picture 4 Right side view of MLS 1200 PYRO 23 1 Magnetron 2 Safety switch 3 220V line inlet and 16A T fuse 4 Electrical connection to external modules options 5 50 pin connection for 240 Remote Control 6 Magnetron tan 7 High voltage capacitor 8 Heating transformer 9 High voltage transformer 10 High voltage diode 11 Exhaust motor 12 Cooling Fan For HV traFo primma h
6. ERROR MESSAGES HOW TO CONTROL THE RAM BATTERY S CHARGHE TROUBLESHOOTING LIST RECOMMENDED SPARE PARTS MLS 1200 PYRO Service Manual rev 1 1996 9 1 10 11 1 INTRODUCTION Each Milestone unit is accurately tested before leaving the manufacturing plant All units are provided with a Quality Test Certificate A proper use and a proper and accurate service are however required to assure long and safe operation of the system 2 GENERAL WARNINGS In order to operate under safe conditions and avoid any danger or risk of accidents the following rules must be strictly followed 1 Always disconnect the unit from the mains power before any repair 2 Before switching the unit on again after every repair it is necessary to make sure that all the internal connections are correctly soldered all the cables are insulated and don t come into contact with either the door or the sharp edges of the unit both the electrical and mechanical connections are virtually faultiess no modifications have been made to the built in safety devices the spare parts are those required by the manufacturer WARNING do not operate the unit if the slightest doubt exists that it is not property working 3 The microwaves generated inside the MLS 1200 PYRO unit have a frequency of 2450 MHz and reach the highest absorption in aqueous matrices causing a rapid increase in temperature This may represent a danger for the operator Therefore avoid
7. above mentioned circumstances have been carefully checked and if necessary seen to 12 5 10 EXHAUSTING FAN The MLS 1200 PYRO units have built in exhausting and ventilation fan placed on the back of the unit see picture 2 n oup x s Picture 2 The airstream generated by this system allows cooling of the parts surrounding the muffle i e hardware removing particles fumes and odours from the working chamber conveying fresh air oxigen to the samples to facilitate burning 13 Exhaust motor p n 50045 TECHNICAL SPECIFICATIONS Voltage 220V Air Volume 64 7 Frequency 50 Hz Speed 2700 round mm Current 016A Noise level 58 dBA Powerinput 35W Admissible Temp 150 C Figure 2 5 11 TEMPERATURE SENSOR P N 33086 The MLS 1200 PYRO unit has two built in temperature sensors Klixon One is located on the magnetron walis and disconnects the microwave emission in case of overheating at a temperature of 110 C 230 F The second sensor is placed on the metal side of the microwave chamber it is activated whenever there is microwave generation inside the unit with no absorbing charge the heating elements are the charge however the temperature of the external side of the chamber exceeds 80 C 176 F the temperature sensor will disconnect the microwave emission The display will show DOOR NOT CLOSED This will last for a few minutes until temperature goes back to
8. both displays show 000 x 1 units LCD and LED check voltage at Pin OUT for 4400mV display must show 550 1 set jumpers for normal operation plug in sensor and check for correct display value bridge TP pads all segments must be illuminated 1888 18 4 Display Adjustment 5 CAL U Adjustment 6 Normal Operation SERVICE CHECKS Step Jumper Settings TP On the event that under normal operation the display doesn t exactly show the sensor s temperature a correction can be achieved via potentiometer P1 Zero Adjust The correction must not exceed a range of 2K C Bigger differences could result from a malfunction of the ATC 300 As an average value the CPU generates the dispayed temperature LCD out of 250 samples which takes some 1 2 seconds delay time compared to the values shown on the red LED display This effect can occasionally lead to a difference of 3 4 between the two displays 7 Preparation B Zero Adjustment 9 Processor Adjustment 10 Normal Operation 11 Display Control Remark Different Display Values 19 6 DESCRIPTION OF COMPONENTS 1 LCD Display 2 Keyboard 3 Attachment of control panel to MLS 1200 PYRO 4 Control panel body Picture 1 Control panel of MLS 1200 PYRO unit 20 Removal of the cabinet cover of the 240 Remote Control Disconnect the 50 pin connection between MLS 1200 PYRO and 240 Remote Control
9. to a difference of x 0 Wi is therefore recommended to ropeat the test several times 4 REMOVAL OF THE CABINET COVER Disconnect the unit from mains power to prevent any undesired switching picture 1 and 2 Loosen the two cross screws on the right and left sides of the unit picture 3 Loosen the cross screws placed on the back of the unit picture 4 Remove the cover by lifting it from the back picture 5 Unscrew the middie screw on the base of the back panel It is now possible to reach the high voltage connections picture 6 Picture 1 Picture 2 eo ae H E eve os ete theta eri ut Uu v 2 2 T Picture 5 Ficture 6 u NE enr ind NITE ERR de s ud T gate d x uH A Su 1 E E BEWARE never bypass the serial switch to the 220 V line located on the left back side of the unit But you have to bypass it if you want to make a faulting see Figure below 5 ELECTRICAL CONTROLS When repairing high power transformer capacitors relays and resistance as weil as Magnetron it is possible to get in contact with high voltage Therefore it is necessary to use only instruments with high voltage insulation higher than 5000 Volt Personnel must take the utmost care not to get in contact with high voltage 5 1 SAFETY CONNECTION POWER CORD EARTH Check connection of safe
10. G CHAMBER TO PROTECT THE MICROWAVE DIFFUSER DURING THE TRANSPORT 1 Picture 8 28 61 HOW TO INSTALL MUFFLE KIT P N 35 INSIDE MLS 1200 PYRO UNIT 1 Position the bottom plate P N 50123 inside the PYRO working chamber Figure 1 2 Position the 4 ceramic supports P N 50054 50055 50056 and 50057 at the four corners of the working chamber Figure 1 Figure 1 3 Place the muffle P N 50005 on the 4 ceramic supports carefully introducing at the same time the thermocoupie through the hole in the backwall of the muffle itself Figure 2 4 Cover the end of the thermocouple placed inside the muffle with the ceramic protection tube P N 50064 Figure 2 1 1 1 1 1 1 1 le qum dh ee GRO ER Figure 2 29 5 Introduce the plate P N 50058 inside the muffle with heating elements turned to the rear side of the muffle in close contact with the thermocouple Figure 3 6 Place the front frame P N 50059 on the front ceramic supports to perfectly posizion the muffle Figure 3 Figure 3 7 Place on top the ceiling P N 50053 to cover the muffle and the front frame Figure 4 Figure 4 8 Close the muffle access inside the muffle using the door P N 50060 Figure 4 30 7 HOW ADJUST THE TEMPERATURE VALUE When the temperature value T2 reading on the displ
11. MILESTONE MLS 1200 PYRO MICROWAVE ASHING MODULE service manual Thank you for having selected our system and welcome in the ever growing world club of Milestone users We are sure that you will be completely satisfied with this new tool entering your laboratory We invite you to read carefully this service manual and to keep it in reach for convenient and fast consulting For any possible clarification or any request of intervention please contact either our 273857 Milestone number 575498 Milestone number Representative in your country or Milestone at the following address MILESTONE s r l Customer Service Dept Via Fatebenefratelli 1 5 24010 SORISOLE BG ITALY Phone 4 lines 39 35 T country code Bergamo city code Telefax 39 35 Italy country code Bergamo city code INDEX OF CONTENTS INTRODUCTION GENERAL WARNINGS MEASURING OF POWER REMOVAL OF CABINET COVER ELECTRICAL CONTROLS SAFETY CONNECTION POWER CORD EARTH DOOR SWITCHES HEATING TRANSFORMER TEST HIGH VOLTAGE TRANSFORMER TEST CAPACITOR TEST DIODE TEST MAGNETRON CONTROL ANODE CURRENT HIGH FREQUENCY LEAKAGE EXHAUST SYSTEM TEMPERATURE SENSOR TEMPERATURE MEASUREMENT SYSTEM DESCRIPTION OF COMPONENTS HOW TO INSTALL THE MUFFLE TEMPERATURE ADJUSTMENT ELECTRIC WIRING DIAGRAMS AND EXPLODED VIEW 5 1 5 2 5 3 5 4 5 5 5 6 5 7 5 8 5 9 5 10 5 11 5 12 6 6 1 7 8 9
12. N 33051 The consequence of an open capacitor is that no high voltage gets to the magnetron A shorted capacitor normally interrupts the fuse for current overload An electrical resistance meter can be used to check a discontinued or shorted capacitor 1 Unplug the unit from the power grid and wait 1 minute before getting in contact with the high voltage parts loosen the capacitor with an insulated screwdriver and disconnect the capacitor wires 2 Set the resistance meter to the highest value and measure the resistance between the capacitor terminals The resistance meter must indicate for a short time interval the flow between the terminals when the capacitor is charged it must indicate an infinite value 3 resistance meter shows a continuous flow between the terminals of the capacitor or no current flow at all is detected it is necessary to replace the capacitor 4 Measure the resistances between both capacitor terminals and the cover of the capacitor The resistance meter must indicate an infinite value 5 6 DIODE TEST P N 33054 Disconnect the unit and wait for 1 minute loosen the capacitors with an insulated screwdriver and disconnect the capacitor wires and the diodes connections Measure the resistance at the highest value terminals Then invert the wires and observe the flow on the measuring instrument A normal diode has an infinite resistance in one direction and a weak resistance in the opposite direction If i
13. all programs KILL ALL PROGRAMS and set a new one In case the unit is newly installed or the EPROM memory has been replaced keep the STOP key pressed until you hear a whistle which informs that the unit is initilized 45 9 1 HOW TO CONTROL THE RAM BATTERY S CHARGE You can check RAM battery buffer when power off the system and messure the voltage between the RAM PINS GND VCC Proceed as follow Detect with diagram in Figure 1 the position of RAM and battery in the CPU board TT lil 1 li Hi D A Power m 5712 5711 Figure 1 CPU card top view of the main components Take a multimeter and select VDC V Measure the voltage as shown in Figure 2 VCC A 27 25 25 24 23 22 21 20 19 18 17 16 15 2 3 4 5 6 7 B 12 13 4 GND Figure 2 RAM Pin Table Pin No Name 14 GND Ground 28 5 buffer voltage off the RAM 20 CS Chip Select 5V 46 When you can t measure 5V between Pin 14 and Pin 28 check in the CPU board the battery buffer circuit below RAM PIN 28 20 CH T T C12 If the voltage measured is lower than 2 5V replacement of the battery is needed RENATA AY Figure 2 Schematic of lithium battery DIAGNOSIS A Check perfect connection of 50 5 cable between PYRO and M240 Control Terminal B Repeat switching on of the unit by MAIN SWITCH placed on the front frame of the PYRO
14. alue on the red dispaly and that read on the M240 is 1 2 4 5 6 f MEAT t Maia ie O EUR 2109 11 tez 7H0S 3 lp L1 a 1 Electric diagram of MLS 1200 PYRO ELECTRIC WIRING DIAGRAMS 8 TEES EE ai ae eee Le cua AAA latte Inr Ua 2 B e sae rage Rr de eR eater Ce O ct 4 HEATING TXF 14 RELAY EE 45 FUSE 10A 13 MAGNETRON CONTROL BOARD 31 pepojdxe 0021 STW erg 46 CONTROL CABLE 34 Description Magnetron Magnetron fan High voltage transformer Heating transformer High voltage resistance 4MOhm 2W Exhaust motor High voltage diode SCL 11 Z 2B5 Ceramic tube for thermocouple Resistance 100hm Capacitor for Magnetron fan Safety microswitch on right left door Door microswitch on right teft door Magnetron control board Relay board Line filter 20A 220V Diffuser axte 75mm in PTFE Diffuser motor MW 220W Complete door working chamber Heating elements Microwave diffuser Back left ceramic support of muffle Back right ceramic support of muffle Front left ceramic support of Front rigth ce
15. any exposure tothe microwave field generated by the magnetron 3 POWER MEASUREMENT Proceed along the following guidelines 1 take out of the middie of the unit the complete muffie leaving the ceramic base placed at the bottom of the working chamber see Picture 1 Picture 1 3 fillin a cylinder shaped pyrex container diameter approx 20 22 cm with 1 liter of water x 25 mi 4 introduce the pyrex container into the working chamber 5 bend the thermocoupie as far asit reaches the water 6 read on the display placed on the front of the unit the initial temperature of the water 7 start the previously stored program at point 2 8 at the end of the program check final temperature Tf as soon as it becomes stabile reading the display again 9 calculate the working power using the following formula E DA ru Va VES m pe 5 nes T MD wb 2 T EF deed H i xe TUR ELE VUE z Hales ERI am ER RE Pp AE A Ek LEE TET Hopi tet iS chs ce AA A A This procedure is according to Norms 705 NOTE Ti and Tf temperature measurements must be extremely accurate as 7 C deviation equivalent when calculating the power
16. ay of the MEGA 240 Contro Terminal does not match with the actual temperature reading on the display in front of the MLS 1200 PYRO unit new calibration of the system is required This procedure has to be followed also in case of replacement of some active parts of temperature measurement or control e g K Thermocouple ATC 300 5 Interface board CPU board How to proceed 1 Open the M240 terminal control by removing the 6 screws 2 in front and 4 behind 2 Remove the M240 top panel the one with the display and lay it beside the base panel which contains the CPU without removing the connections between the two parts See Figure 1 Figura 7 M240 open view In this way it is possible to calibrate the CPU T2 potentiomenter and read the values on the display 3 Install the following microwave program Time 1h Power 1000W T2 1000 31 Read the temperature value on the red display located on the front frame of the Pyro see Figure 2 Figure 2 By means of a screwdriver regulate the 10 Kohm potentiometer T2 on the CPU board see Figure 1 Adjuste the potentiometer T2 until the remote control display value T2 corresponds to the front frame LED Display of the MLS 1200 Pyro Start the microwave program installed in point N 3 Repeat the operations in points 4 and at approximately every 100 C until reaching 1000 P S The difference allowed at 10007 between the real v
17. d high voltage transformer 3 Connect the Voltmeter to the terminals of the magnetron wires 4 Connect the unit to the mains power and start a program with microwave power e g 1000 W for 1 minute The heating voltage should be around 4 6 VAC ATTENTION Disconnect the unit from the mains power before disconnecting the Voltmeter If the Voltmeter indicates no voltage connect the wires with the capacitor set the Voltmeter to the correct measurement range and check if 220 V 230 V are available f the input voltage is normal but there is no voltage in the heating wires it will be necessary to replace the transformer The resistance at the terminals of the heating transformer must be z 13 Ohm on the primary winding z 0 8 Ohm on the secondary winding 54 HIGH VOLTAGE TRANSFORMER TEST P N 33044 As about 2300 VAC are available at the secondary winding of the transformer during operation no high voltage measurement should be carried out Normally it is enough to check the current flow to make sure of the state of the transformer 1 Disconnect the unit loosen the capacitor with an insulated screwdriver and disconnect the transformer wires 2 Measure the resistance value between the high voltage terminals with an electrica resistance meter it should turn out to be about 40 Ohms 3 much lower a much higher or an infinite resistance is measured the transformer is faulty and must be replaced 5 5 CAPACITOR TEST P
18. defec ted 11 RECOMMENDED SPARE PARTS P N 33 Fuse 16AT 250V P N 33300 Fuse 19 250 P N 33940 CPU Board Mega 240 installed inside the Remote Control HIGH FREQUENCY LEAKAGE TEST SEE PARAGRAPH 5 9 P N 33700 Leak tester microwave radiation measurement
19. e ters that are not set by the operator Difficulty in breaking the working program Autostart of a working program Microwave emission is not controlled when preset temperature value T2 is rea ched The T2 value on the display of M240 Control Terminal does not correspond to the actual reading on the red dispaly pla ced on the PYRO front frame 48 PROBLEM DIAGNOSIS The red display on the front frame of the A H the dispaly shows figure 1 unit shows absurd values e g 1 or 1323 replace the ATC 300 S card see para graph 5 12 If tha display shows x 1323 check connection between the thermo couple and the ATC 300 5 card replace the thermocouple The unit doesn t switch on Fuse 16AT 250V power mains grid Front Switch Filter Safety switch the cover There is no microwave emission Magnetron Heating transformer Right and left door slide switches Right door handle switch Fuse 10AT 250V on power board The magnetron fan is malfunctioning which causes magnetron overheating and activation of the temperature sensor loca ted on magnetron After 5 second magnetron heating time the The door is not perfectly closed program doesn t start and the display Left door handle switch shows DOOR NOT CLOSED Exhaust fan is blocked with consequent over heating of the uW chamber therefore the temperature sensor intervenes The temperature sensor klixon is
20. erence Number Q CB Moh Oh 35 POWER CARD AUTOSUPPLY LOWER RIGHT SWITCH MAGNETRON FAN DIFFUSER MOTOR DOOR UPPER HEATING LEFT SWITCH TRANSFORMER COOLING FOR HV TRAFO BLACK ORANGE Black RING TRANSFORMER MICROWAVE VENTILATOR POWER GRID INLET NEUTRAL LINE SWITCH mu POWER CARD INLET O o p o Figure 3 Relays card side view of components 5 5 r E A H 1 i 36 1 12 211565 13 Eta 5115 9114 575 5715 5 tT 5115 2 5 EiS 5112 5115122 5115 stish ish BL 7 STASH2 3 5116 57453 1 715 1 57113 1 3114 lay 4 5119 1 256v m HM 17 S735 357 ji vDAE rivas 250 A Jon ST i 5115 10 ste i Li Ves ta Llak 200 137 cs 1 e7aF 14 250 vola RS ite y WA 470 0 54 115 27 171 134 RELI RELI 12 31151 571 Figure 4 Electric diagram of relays Figure 5 Power supply side view of components TOt rl Figure 6 Electric diagram of power supply AGT 91001 Att 204449 2 2 t5 Este 1 i 8 14 ineo 1 2 1 a HU IVA 2121 six able 15 1 416 0 Ati v ONG UND O S
21. k Tester P N 33700 supplied by Milestone The test is as follows 1 Switch on the Leak Tester 2 Operate the unit at full power 1000 W for one minute 3 Check the MLS 1200 PYRO unit for leakage gently moving the Leak Tester Start from the upper right side of the door and proceed clockwise all around the door until you get back to the starting point Carry out a similar test on all the visible screening NOTE in order to perform a correct high frequency leakage check the unit must be positioned in Such a way that the meter can easily be used perpendicularly to the lower door edge IMPORTANT in case of radiofrequency leakage do not absolutely operate the unit until it has been perfectly repaired Possible causes of microwave leakage are the following 1 The door doesn t close well against the working chamber 2 is broken 3 The radiofrequency door washer is damaged 4 The door is bent or the unit presents some other visible damages which could cause microwave leakage 5 There are faulty parts in the connections 6 There are faulty parts in the microwave generator The following points must always be checked after every repair 1 Has the RF magnetron washer been correctly installed 2 Are the working chamber and the microwave drive in perfect conditions 3 Can the door be properly closed and do the safety devices operate correctly IMPORTANT Do not connect the unit for any reason until the
22. mic surface sensibly shorten its life 10 5 8 ANODE CURRENT The anode current gives an indication on the status of the magnetron When the magnetron becomes old the resistance at the wires is increased and the anode current is decreased For the measurement of the anode current follow these instructions Disconnect the unit and take the plug out wait for 1 minute Check the Ohm value of the resistance connected with the diode s grounding The correct value is 10 Ohms Connect a Voltmeter with a measuring range of minimum 5 V at the resistance terminals Connect the unit and start a program with 100 96 power Do not forget to introduce a microwave absorbing charge for example water into the unit Measure the voltage which with magnetron type 24121 must be about 4 3 NOTE Don t touch the Voltmeter during the measurement The anode current can be measured by the following equation 1A 4 3 V 10 Ohm 0 43 A Figure 1 The anode current for the Magnetron type 29121 must be 430 mA 10 mA at 10096 power With an anode current lower than 410 mA it is necessary to replace the magnetron It may also be that some component is not properly working in the high voltage parts capacitors diodes which might result in a lower current 11 5 9 HIGH FREQUENCY LEAKAGE IMPORTANT a high frequency leakage test must be carried out before and after every repair To perform this test use the Lea
23. om owe 200 Cm om wm omm Lom s ICE 1300 Under 40 and over 1000 C the tolerance of the thermocouple is subject to substantial variations 17 CALIBRATION OF THE ATC 300 S ELECTRONIC BOARD AND DISPLAY Technical Specifications ATC 300 S Temperature Range 0 1250 C Solution 1K Accuracy 0 083 MBEW Output Voltage OV 10V Supply Voltage 12V and P1 P2 P3 Figure 4 Top View ATC 300 with Potentiometers and Jumpers CALIBRATION OF ATC 300 AFTER ASSEMBLY Step Jumper Settings Calibration and Checks 1 Preparation Connect ATC 300 without Sensor 2 Zero Adjustment ee With potentiometer P1 adjust voltage of Pin 1 8 OUT to 0 000V A the dispaly shows 000 1 3 Gain Control a at jumper pins 1 und _ a voltage of o 22 772 mV needs to be applied at pin 8 should be a voltage toward pin 1 o CHAS CHM 9 of 555 mV 5mV Zero offset at pin 8 OUT should be a voltage of 4400mV 40mY note the actual value for step 5 the voltage of 22 772 mV is still applied at pin 1 and pin 2 with P2 adjust the displayed number to 550 units with potentiometer P3 adjust voltage at pin OUT to the value measured in step 3 set jumpers for normal operation Calibration and Checks Connect ATC 300 without Sensor check voltage at Pin OUT for 0 000 V 1 mV
24. ramic support of muffie Boat stop ceramic stopper Thermic switch of ceiling of the microwave chamber Thermic switch of magnetron Support for heating elements Rubber feet Fan 220V 50 60Hz LCD Display for 240 Remote Control Flat keyboard for 240 Remote Control Power supply 12V 5V 24V Complete CPU Board for 240 Remote Control Capacitor 1 14uF 50Hz Capacitor 1uF 2 Toroidal transformer 10A fuse for magnetron control board 16A fuse line fuse interface board complete with 50 pin Cable for 240 Remote Control 50 pin cable for 240 Remote Control ATC 300 S Electronic board Display Remote Control for Mega 240 CPU included Thermocouple Type K Fixing element for thermocouple I Safety switch 220V Fixing element for thermocouple ll Fixing element for thermocouple Cable between interface board and relay board Frontal frame for MLS 1200 PYRO Complete chassis cover for MLS 1200 PYRO Front frame of muffle Muffle door Ceiling of muffle Muffle Bottom Plate of muffle Cooling Fan For HV traFo Part Number 33040 33042 33044 33046 33048 50045 33054 50064 33058 33060 33062 33064 33066 33068 33100 33072 33074 33077 33965 33080 50054 50055 50056 50057 50046 33086 33086 50058 33090 33304 33258 33259 33716 33930 33053 33051 33319 33300 33301 33727 33916 33726 33930 33973 33507 33096 33598 33599 33316 33221 30333 50059 50060 50053 50005 50123 50045 Ref
25. t shows a current flow or an infinite resistance in both directions it is necessary to replace the diode NOTE Resistance meters with a battery of less than 6 to 9 Volts are generally not suitable for checking the diodes in the case of an infinite resistance in both directions the unit should first be used on a diode which has been proved not to be faulty before replacing a diode when there s no need for it 5 7 MAGNETRON CONTROL P N 33040 The magnetron is shown in picture 1 Ceramic cap HF washer EE hd Picture 1 1 Disconnect the unit from the mains power and wait for one minute 2 disconnect the high voltage wires from the wire terminals and measure the resistance between magnetron terminals 3 connect the resistance meter between the magnetron wires and the magnetron case earth the read out of the resistance meter must be an infinite value A lower resistance means that the magnetron is defective and must be replaced 4 Check the two terminals The resistance should be maximum 300 milliOhm A higher resistance means a fault in the wires or cut off wires and sometimes also the magnetron has to be replaced Absolutely do not use the unit in case of missing or faulty washers The washer wrapped all around the magnetron prevents any microwave leakage between magnetron and magnetron drive CAUTION the ceramic cap must not get damaged or scratched by metall c parts as even very small scratches on the cera
26. ty contact to the plug of the unit The resistance must not exceed 100 mOhm 52 DOOR SWITCHES P N 33062 and P N 33064 The unit is provided with 4 safety switches The two switches placed on the upper right and left sides of the MLS 1200 PYRO unit are operated by closing the door They open when pushing the door handle downwards This means that when the door is closed these switches are also closed When the door is open these switches are open too The lower switches are safety switches and are also activated by the door arm To check the correct functioning of the switches use an electrical resistance Ohm meter Right and left door slide switches CLOSED DOOR R 0 ohm OPEN DOOR R infinite Right and left door handle switches CLOSED DOOR R 0 ohm OPEN DOOR infinite When the door is closed the switches are open and viceversa BEWARE when pushing down the door handle be careful that the upper left switch is activa ted before the right one Defective switches must be destroyed to prevent future use 5 3 HEATING TRANSFORMER TEST P N 33046 CAUTION During the operation about 2300 VAC get to the high voltage terminals While using the measurement instruments keep your hands tools etc off the high voltage terminals To check the heating transformer proceed as follows 1 Disconnect the unit and loosen the capacitor with an insulated screwdriver 2 Disconnect the connecting cable between capacitor an
27. values below 69 C 156 F and the Klixon is reactivated 14 5 12 TEMPERATURE MEASUREMENT SYSTEM Temperature Measurement System in MLS 1200 PYRO includes the following parts 1 Thermocouple type NiCr Ni with measuring range 200 1300 C which is installed in the back of the unit see Picture 3 Picture 3 The thermocouple is introduced inside the working chamber into the muffle where temperature measurement takes place see figure 3 Thermocouple with ceramic tube protection Figure 3 15 2 Electronic Card with ATC 300 S display with measuring range between O C and 1250 C The ATC 300 S card is placed on the front panel for easy temperature reading see Picture 4 FT e LEITET ALS pu Picture 4 The ATC 300 S card receives signal in mV from the thermocouple and converts it into mV graduated vatue to attain temperature reading on the dispiay generate an analogic signai for microprocessor control of temperature generate an analogic signal for external connections recorder PC etc 857 ue n 16 CALIBRATION OF THE THERMOCOUPLE The following comparison table allows to check correct functioning of the NiCr Ni thermocou ple according to DIN IEC 584 1 Norms C Cm 5 L
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