mirak™ 4-place stirrers and stirring hot plates mir… · 28-05-1999 · your thermolyne...

MIRAK™4-Place Stirrers andStirring Hot Plates

OPERATION MANUAL AND PARTS LISTSERIES 846, 847

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BARNSTEAD|THERMOLYNE

Model # Voltage DescriptionS73130 240 12x12S73130-26 220-240 12x12S73134 100 12x12S73135 120 12x12SP3230 240 12x12SP73230-26 220-240 12x12SP73235 120 12x12SP73235-60 120 12x12SP73238 208 12x12SP73238-60 208 12x12

LT847X2 • 5/28/99

Safety Information ..............................................................................................................................................3Alert Signals..................................................................................................................................................3Warnings ......................................................................................................................................................3

Introduction..........................................................................................................................................................6Unpacking ..........................................................................................................................................................7Installation ..........................................................................................................................................................8Principles of Operation......................................................................................................................................10Operation ..........................................................................................................................................................12

Removing the Clear Plastic Cover..............................................................................................................12The Power Switch ......................................................................................................................................12Setting the Stirring Speed ..........................................................................................................................13Stirring Speed Guide ..................................................................................................................................14Setting the Temperature ............................................................................................................................14Controlling Top Plate Temperature ............................................................................................................16Controlling Solution Temperature ..............................................................................................................16Using the Probe with the Temperature Display for Stirring Applications Only............................................17To Achieve Fast Heat-up of Large Volumes ..............................................................................................17Heating Small Volumes ..............................................................................................................................18Heating Metal Vessels and Sand Baths ....................................................................................................18Heat-up Time Guide....................................................................................................................................19

Operating Specifications ..................................................................................................................................20Heating Specifications ................................................................................................................................20Stirring Speed Specifications......................................................................................................................20

General Operating Specifications ....................................................................................................................21Dimensions........................................................................................................................................................21Electrical Ratings ..............................................................................................................................................21

Temperature Range for Hot Plates and Stirring Hot Plates........................................................................21Stirring Speed Range fro 4-Place Stirrers and Stirring Hot Plates ............................................................21Environmental Parameters for all Units ......................................................................................................21

Maintenance and Servicing ..............................................................................................................................22Replacing the Power Board and/or the Logic Board ..................................................................................22Replacing the Display Board ......................................................................................................................24Replacing the Motors..................................................................................................................................26Replacing the Top Plate Assembly ............................................................................................................28Set-up Procedure........................................................................................................................................31Calibrating the Probe Temperature Input....................................................................................................33

Troubleshooting ................................................................................................................................................35Exploded Views ................................................................................................................................................36Replacement Parts............................................................................................................................................38Ordering Procedures ........................................................................................................................................39One Year Limited Warranty ..............................................................................................................................40

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Table of Contents

Your Thermolyne MIRAK™ 4-Place stirringhot plate has been designed with function,reliability and safety in mind. It is the user’sresponsibility to install it in conformance withlocal electrical codes.

This manual contains important operating andsafety information. The user must carefullyread and understand the contents of the man-ual prior to the use of this equipment.

WarningsTo avoid electrical shock, always:

1. Use a properly grounded electricaloutlet of correct voltage and currenthandling capacity.

2. Disconnect from the power supplyprior to maintenance and servicing.

To avoid personal injury:1. Do not use in the presence of flam-

mable or combustible materials; fireor explosion may result. This devicecontains components which mayignite such materials.

2. Keep top surface clean. Use a non-abrasive cleaner. Alkali spills, hydro-fluoric acid spills or phosphoric acidspills may damage top and lead tothermal failure. Unplug unit andremove spills promptly. Do notimmerse unit for cleaning.

3. Replace the top immediately if dam-aged by etching, scratching or chip-ping. A damaged top can break inuse.

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Safety Information

WarningWarnings alert you to a possibility of personal injury.

CautionCautions alert you to a possibility of damage to theequipment.

NoteNotes alert you to pertinent factsand conditions.

Hot SurfaceHot surfaces alert you to a possibility of personal injury if youcome in contact with a surface during use or for a period of time after use.

Alert Signals

4. Do not remove or modify groundedpower plug. Use only properly groundedoutlets to avoid shock hazard. Not ratedfor use in hazardous atmospheres.

5. Use caution when heating volatile mate-rials; top surface and element can reachthe “Flash Point Temperature” of manychemicals. These stirrers and stirringhot plates are not explosion proof. Fireor explosion may result. Unit containscomponents which may ignite suchmaterials.

6. Use appropriate hand and eye protec-tion when handling hazardous chemi-cals.

7. Caution: Hot Surface. Avoid Contact.The hot plate will remain dangerouslyhot with no visible indication for sometime after use.

8. Do not use in highly corrosive atmos-pheres; corrosive fumes and spill maydamage top and internal components,creating a shock hazard.

9. Refer servicing to qualified personnel.

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SAFETY INFORMATION

CautionSpace unit 12 inches away fromcombustible materials under anyconditions.

Gross weight of items placed ontop of 12”x 12” stirrers and stir-ring hot plates should notexceed 30 lbs.

Please note the following WARNINGS:

WarningThis warning is presented for compliance with California Proposition 65 and other regulato-ry agencies and only applies to the insulation in this product. This product contains refracto-ry ceramic, refractory ceramic fiber or fiberglass insulation, which can produce respirabledust or fibers during disassembly. Dust or fibers can cause irritation and can aggravatepreexisting respiratory diseases. Refractory ceramic and refractory ceramic fibers (afterreaching 1000°C) contain crystalline silica, which can cause lung damage (silicosis). TheInternational Agency for Research on Cancer (IARC) has classified refractory ceramic fiberand fiberglass as possibly carcinogenic (Group 2B), and crystalline silica as carcinogenic tohumans (Group 1).

The insulating materials can be located in the door, the hearth collar, in the chamber of theproduct or under the hot plate top. Tests performed by the manufacturer indicate that thereis no risk of exposure to dust or respirable fibers resulting from operation of this productunder normal conditions. However, there may be a risk of exposure to respirable dust orfibers when repairing or maintaining the insulating materials, or when otherwise disturbingthem in a manner which causes release of dust or fibers. By using proper handling proce-dures and protective equipment you can work safely with these insulating materials andminimize any exposure. Refer to the appropriate Material Safety Data Sheets (MSDS) forinformation regarding proper handling and recommended protective equipment. For addi-tional MSDS copies, or additional information concerning the handling of refractory ceramicproducts, please contact the Customer Service Department at Barnstead|ThermolyneCorporation at 1-800-553-0039.

Please read all the information in this manual before operating the unit.

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SAFETY INFORMATION

WarningRefer servicing to qualified personnel.

Your Thermolyne MIRAK™ 4-place stirrer orstirring hot plate is a general purpose stirring orstirring and heating plate designed for laborato-ry procedures requiring precise control of tem-perature and/or stirring speed. Each 4-placeMIRAK model includes a digital display for mon-itoring actual stirring speed, and the stirring hotplate models have dual displays so temperatureand stirring speed can be monitored simultane-ously. The 4-place stirring hot plate is capable ofproducing accurately controlled temperaturesfrom 40°C through 540°C on all 208 volt and240 volt models. 120 volt models have a tem-perature range of 40°C to 370°C. The tempera-ture may be controlled at the plate surface byinternal Type K thermocouple sensor, or thesolution temperature may be controlled utilizingan accessory ungrounded Type K thermocoupleprobe. A 6” or 10” general purpose stainlesssteel immersion probe or chemical-resistant 7”

solid Teflon® immersion probe may be orderedseparately. The stirrer will accurately maintainstirring speeds from 60 rpm up to 1200 rpm. Onstirring hot plate models, the accessory probemay also be utilized to display the actual tem-perature of heat-sensitive solutions duringstirring-only functions. The top plate on theMIRAK 4-place units is solid ceramic and is suit-able for use with glass or metal vessels.

Your MIRAK 4-place stirrer or stirring hot platemay be used for general purpose heating appli-cations and/or general laboratory mixing of solu-tions including; sample preparation, heatingreagents, melting paraffin, warming resinouschemicals, content analysis, solvent evapora-tions, digestions, media preparation and sterili-zation, titrations, sand baths and microscalechemistry applications.

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Introduction

1. Remove your MIRAK 4-place stirreror stirring hot plate from the carton.

2. Inspect to ensure that the unit has notbeen damaged during shipment.

3. If the unit appears to have sustainedshipping damage, contact the distribu-tor from whom you purchased thisproduct or call Barnstead|ThermolyneCustomer Service at 800-553-0039.

4. Remove the packaging from under-neath the top plate by gently pullingthe packaging material toward you.

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Unpacking

NoteA special 20-amp cordset isincluded on the CSA-approvedmodel of the 12” x 12” 120 voltMIRAK 4-place stirring hot plate(SP73235). This 20-amp cordsetcan only be plugged into a non-standard 20-amp, 120 volt wallreceptacle. If you do not have theappropriate receptacle, contact aqualified electrician for installationof a 20-amp 120 volt outlet.

A 12” x 12” 120 volt MIRAK 4-place stirring hot plate (SP73235-60) is available with a standard15-amp, 120 volt cordset.Thismodel is not CSA-approved.

1. Set the unit on a flat, stable surface atleast 12” away from combustible materi-als and plug the cordset into a properlygrounded electrical outlet of correct volt-age and current handling capacity

2. Use your right hand to locate theON/OFF power switch which is on theside, near the front right corner as youface the unit.

3. Press the black ON/OFF power rockerswitch to the ON position. The red LEDdisplay(s), and the green power light tothe left of the display(s) should illumi-nate. The unit is ready for operation.

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Installation

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INSTALLA TION

Back View

Front View

Each MIRAK unit utilizes the latest in micro-processor technology to deliver the most reli-able, accurately controlled, ceramic top hotplate, stirrer and stirring hot plate on the market.

Your MIRAK 4-place 240 volt and 208 volt stir-ring hot plate has an electronic closed loopfeedback control which will accurately maintaintemperature setpoints from 40°C to 540°C. The120 volt MIRAK 4-place stirring hot plate willmaintain temperature setpoints from 40°C -370°C. The top plate surface temperatures arecalibrated and verified at the factory using thelatest in infrared temperature measurement. Themeasurements are made with an infrared metermounted approximately 26” above the top sur-face of the hot plate or stirring hot plate. If thetemperature measurement of the ceramic top ismade with measurement devices other than theinfrared, the error of the measuring techniquemay be greater than the error of the unit.

The MIRAK stirring Hot Plate units use anungrounded Type K thermocouple for measuringboth the top plate temperature and the solutiontemperature when using the probe. Both topplate surface and probe temperature are meas-ured with independent analog circuits. This pro-vides a significant increase in certain types ofmetal vessels and sandbaths on the MIRAKwithout damaging the ceramic top. However, werecommend that you do not control the temper-ature with a probe when heating a metal vesselor a sandbath.

The electronic stirring speed control on 4-placeMIRAK units will maintain the speed setpointwhen the unit is loaded at ±4 rpm as displayedby the LED display on the unit. There are four

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Principles of Operation

individual motors in the MIRAK 4-place stir-rers and stirring hot plates which producemaximum stirring torque under normal labora-tory load conditions. Each motor is combinedwith a powerful magnet to provide exceptionalmagnetic coupling with a stirbar. Each motoris centered beneath each of the four stirringpositions indicated by the circles silkscreenedon the 12” x 12” top plate. All four motors willoperate at the same speed.

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PRINCIPLES OF OPERATION

Removing the Clear PlasticCoverYour MIRAK unit has a protective plastic coverover the front control panel. This plastic cover isdesigned to protect the control knobs and thedisplay panel from spills, and should remain inplace when the unit is being used. To use theknob(s) while the plastic cover is in place, spinthe knob(s) from the bottom where the knobprojects below the plastic cover. This plasticcover can be easily removed for cleaning bygrasping the cover at each bottom corner andgently pulling the sides of the plastic cover awayfrom the case while lifting the cover toward you.To replace the cover simply slide it back ontothe case.

The Power SwitchYour MIRAK unit has a separate ON/OFF powerswitch which is a black rocker switch located onthe lower front corner of the right side as you’refacing the unit. This separate power switchallows you to turn your MIRAK hot plate, stirreror stirring hot plate on or off without disturbingyour temperature and/or speed setting. Your lastsetpoint will be held in memory even if the unitis unplugged and will reappear on the display assoon as the unit is powered up again.Whenever the power is on, a green power lightilluminates on the front control panel.

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Operation

Setting the Stirring SpeedThe 12” x 12” top plate will accommodate upto four 1 liter vessels, one at each stirringposition. The 4-place MIRAK will also stir two2 liter flasks simultaneously with up to two 1liter flasks, one at each of the other two stir-ring positions. Actual stirring speed may differbetween larger vessels and smaller vesselsstirred simultaneously, depending on theamount and the viscosity of the solution ineach flask.

Your MIRAK 4-place stirrer or stirring hotplate has an electronic feedback speed con-trol which will maintain a precise speed set-point from 60 rpm to 1200 rpm with accuracyof ±2 rpm. Maximum speed at each positionis dependent on viscosity of the solutionand/or the amount of solution in each vessel.The MIRAK stirrers and stirring hot plates areequipped with a strong magnet and hightorque motor which will draw a vortex in up to1800 ml of water stirred in a 2 liter flask witha new 2” stir bar.

To set the speed, spin the SPEED CONTROLknob until your desired setting is indicated onthe digital display. As you move the knob, theSET light next to the RPM display will illumi-nate. Turn the knob clockwise to increase thespeed or counterclockwise to decrease thespeed. The unit will not start to stir until youpress the speed control knob. Once the unitbegins stirring, the display will register ACTU-AL speed and the SET light will no longer beilluminated. To check your setpoint, move theknob counterclockwise one position. You willfeel a click, the SET light will illuminate andyour setpoint will be displayed again for five

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OPERATION

seconds. After five seconds the display willautomatically return to indicating actual speedand the SET light will go out. To stop the stirringaction without changing your setpoint, press theknob once. To resume stirring at the set speed,press the knob again.

If you want to ensure that the unit will not startto stir if the knob is inadvertently pressed, turnthe speed control knob until the display indi-cates the word OFF.

Setting the TemperatureYour MIRAK 4-place stirring hot plate has anelectronic closed-loop feedback control whichwill accurately maintain temperature setpointsfrom 40°C through 540°Con the 240 volt and208 volt models. The 240 volt 4-place stirringhot plates will maintain temperatures from 40°Cthrough 370°C. An unloaded stirring hotplate willheat to maximum temperature in just 8 minutes.A HOT light on the front panel will illuminatewhenever the top surface temperature exceeds50°C. The temperature may be controlled eitherat the top plate by the internal Type K thermo-couple sensor, or in the solution using an acces-sory ungrounded Type K thermocouple probe.(A 6” or 10” stainless steel general purpose

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OPERATION

Stirring Speed Guide

Unit Flask Size Stirbar Size Amount of Viscosity Maximum Speed*Solution

4-place MIRAK 1 liter 2” 800 ml water 1200 rpm4-place MIRAK 2 liter 2” 1800 ml water 1200 rpm4-place MIRAK 1 liter 2” 1000 ml cooking oil 700 rpm4-place MIRAK 500 ml 2” 350 ml 30 wt. motor oil 1100 rpm

* Maximum speed obtained without the stir bar loosing coupling with the magnet.(For speed stability and display accuracy please refer to the Operating Specifications.)

immersion probe or a chemical-resistant 7”Teflon immersion probe are available throughyou distributor, or by contactingBarnstead|Thermolyne at 800-553-0039.)Your MIRAK 4-place stirrer or stirring hotplate will accept any ungrounded Type K ther-mocouple probe, however, the accuracy ofprobes other than those we’ve tested andspecified may exceed the probe accuracy rat-ing we’ve designated.

Your MIRAK 4-place stirring hot plate will dis-play the temperature in °C. The display willalways indicate OFF or your last setpoint, andthe SET light will be illuminated until youpress the heat control knob to initiate opera-tion. Once the heat control knob has beenpressed, the ACTUAL temperature of the topplate or the probe will be displayed and theSET light will no longer be illuminated. If youwant to check your setpoint, you do not haveto press the knob again; simply turn the knobcounterclockwise one click. Your setpoint willbe displayed for approximately five secondsuntil the display returns to indicating the actu-al temperature.

A single element covers the entire surface ofthe 12” x 12” top plate and supplies even heatto the entire surface. A single large vessel ornumerous smaller vessels can be heated any-where on the top plate when the stirring func-tion is not in use. Vessels to be heated onlydo not have to be located at the center ofeach silkscreen position.

If you want to ensure that the unit will notheat if the knob is inadvertently pressed, turnthe temperature control knob until the displayindicates the word OFF.

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OPERATION

NoteThe temperature display will notindicate a temperature less than40°C. If the actual temperature isless than 40°C, the word LO willbe indicated until the actual tem-perature reaches 40°C.

WarningCaution: Hot Surface. AvoidContact. The hot plate will remaindangerously hot with no visibleindication for some time after use.

Controlling Top PlateTemperatureYour MIRAK 4-place stirring hot plate will controlthe top plate, and the display will indicate topplate temperature WHENEVER THE PROBE ISNOT PLUGGED IN. When the unit is displayingthe top plate temperature the word TOP on thefront panel will be illuminated.

Controlling SolutionTemperatureTo control your solution temperature simply plugan ungrounded Type K thermocouple probe intothe single probe receptacle located on the backof the unit and place the probe in your solution.The display will indicate the actual temperatureof the solution as measured by the probe, andthe word PROBE on the front panel will be illu-minated.

The solution probe offers more exact tempera-ture control than regulating the top plate by thethermal internal sensor. If you need to maintaina precise setpoint, we recommend using aprobe to control the solution temperatureinstead of controlling the top plate temperature.

When using a probe with your MIRAK 4-placestirring hot plate, it is recommended that youuse a clamp on a support rod to hold the probein your solution.

To ensure accurate probe readings, as much ofthe probe sheath as possible should beimmersed in your solution.

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OPERATION

NoteThe top plate temperatures willbe higher than your solutiontemperature.

NoteThe top plate temperature willnot exceed 540C.

WarningIf the probe is plugged into your4-place stirring hot plate whilethe heat control is operating butis not in solution, the tempera-ture display will continue to indi-cate an ambient temperature.Because the setpoint cannot bereached, the element will contin-ue to supply heat to the topplate, and the maximum topplate temperature of 540°C maybe reached.

When using the probe accesso-ry, make sure the probe isalways in the solution when theheat control is operating. (AnyType K thermocouple used mustbe an ungrounded type.

To obtain an accurate reading when you areusing the probe and stirring your solution,make sure the probe is immersed in the liquidand is not located in air in the center of thestirring vortex.

Using the Probe with theTemperature Display forStirring-only ApplicationsOn the stirring hot plate model, the probe canalso be utilized to monitor the actual tempera-ture of your solution when you want to stir thesolution without heating. To use the probewithout heating the solution, turn the knobuntil the display indicates OFF and press theknob to initiate operation. The element will notsupply heat to the hot plate. The display willindicate LO if your solution temperatureremains at less than 40°C, or the actual tem-perature of your solution if it is above 40°C.

To Achieve Fast Heat-up ofLarge Volumes

With a ProbeWhen heating large volumes of solution, pre-heat the top plate at maximum temperature toallow the plate to heat the solution quicklybefore plugging your probe into the probereceptacle in the back of the unit. As the topplate heats, monitor your solution temperaturewith a standard laboratory thermometer untilyour solution is approximately 15° below your

17

OPERATION

desired setpoint. Now plug your probe into theunit, change the setpoint to your desired solu-tion temperature, and place the probe in yoursolution.

Without a ProbeIf you are heating larger volumes and do notintend to use the probe to maintain a precisesolution temperature, faster heating can beachieved by turning the heat control knob tomaximum temperature until the solution starts toheat, and then turning the setpoint back to yourdesired top plate temperature.

Heating Small VolumesTo heat small volumes quickly it should not benecessary to preheat the solution at a highertemperature. By not preheating small volumesyou avoid the potential for the temperature toovershoot your desired setpoint. If you plan tocontrol the solution temperature of a small vol-ume sample with the probe, initiate heating withthe probe in the solution; no preheating shouldbe required.

Heating Metal Vessels andSand BathsMetal vessels and sand baths cannot be heatedon most solid ceramic tops because of the ten-dency for the metal and the sand to reflect heatback into the top, eventually exceeding themaximum temperature rating for a ceramic top,which causes it to break. Because theadvanced electronic control in the MIRAK iscapable of precisely regulating the top plate

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OPERATION

NoteIf you allow the top plate toreach the maximum tempera-ture of 540°C while preheatingand then turn the control downto a setpoint less than 200°C,the temperature of the top willdrop rapidly to 200°C. Becauseof the natural cooling charac-teristics of ceramic, the temper-ature of the top will drop muchmore gradually after the topplate temperature reaches200°C.

temperature, metal vessels and sand bathsmay be heated safely without the danger ofthe ceramic top breaking.

When heating metal vessels and sand bathshowever, we recommend that you DO NOTuse the probe to control the temperature.Because of the heating and cooling propertiesof metal and sand, the sample temperaturesfluctuate, which will result in unstable topplate temperatures. We achieved betterresults controlling the top plate temperature,which allowed us to maintain a constant levelof heat to the sand bath or metal vessel. Thetop plate setpoint should be set approximately100° above the temperature required for yoursample, and the sample temperature may bemonitored with a standard laboratory thermometer.

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OPERATION

Heat-up T ime GuideUnit Temperature Setpoint Flask Size Amount of Solution Time to V igorous Boil12” x 12” 120 volt MIRAK 540°C 1 liter 1000 ml (water) 26 min.12” x 12” 120 volt MIRAK 540°C 2 liter 1800 ml (water) 32 min.12” x 12” 120 volt MIRAK 540°C 4 liter 4000 ml (water) 46 min.12” x 12” 120 volt MIRAK 540°C 1 liter 1000 ml (water) 17 min.12” x 12” 120 volt MIRAK 540°C 2 liter 1800 ml (water) 21 min.12” x 12” 120 volt MIRAK 540°C 4 liter 4000 ml (water) 25 min.

Top Plate Surface Solid Ceramic

Heating Specifications Temperature range: 40°C - 540°C

Heat-up time to maximum temperature (unloaded top plate) 8 minutes

Temperature stability at plate surface (@ 70°C) ± 2.0°C

Stability of the solution temperature (400 ml of water in a 1000 ml glass flask):

Controlled by the top plate at 70°C setpoint (solution maintained at 30°C) ± 1.0°C

Controlled by the immersion probe at 70°C setpoint (solution maintained at 70°C) ± 1.0°C

Accuracy of the temperature display vs. the actualtemperature of the hot plate (setpoint 70°C). Top plate temperature was verified with an infrared meter mountedapprox. 26” above the top plate surface ± 1.0°C

Accuracy of the temperature display vs. the actualsolution temperature as measured by the stainlesssteel or Teflon immersion probe (setpoint 70°C) ± 1.5°C

Stirring Speed SpecificationsSpeed range(maximum speed is dependent on the viscosity of the solution) 60 - 120 rpm

Stability of the stirring speed setpoint (600 ml of water in a 1000ml glass flask) ± 4.0 rpm

Accuracy of the speed display with the actual stirring speed ± 2.0 rpm

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Operating Specifications

Top Plate Size Max. Recommended Flask Size Max. Weight on T op Plate12” x 12” 2 liters* 30 lbs.12” x 12” 6 liters** 30 lbs.

* A maximum of two 2 liter flasks can be accommodated on the 12” x 12” top plate when the stirringfunction is in use. Up to two 1 liter flasks can be accommodated simultaneously at the other twostirring positions.

** A maximum of one 6 liter flask can be accommodated on the stirring hot plate when heating only.

Dimensions - 12” x12” modelsModel Numbers SP73235

SP73235-60SP73230 S73135SP73230-26 S73130SP73238 S73130-26SP73238-60 S73134

Overall Width 13.500 (34.29) 13.500 (34.29)Overall Height 6.750 (17.15) 6.438 (16.35)Overall Depth 16.625 (42.23) 16.625 (42.23)Top Plate Width 12.375 (31.43) 12.375 (31.43)Top Plate HeightTop Plate Depth 12.375 (31.43) 12.375 (31.43)Weight lbs. (kg) 25.74 (11.68) 22.13 (10.04)

Electrical Ratings - 12”x 12” ModelsModel No. Volts Amps Watts Freq. PhaseS73130 220-240 0.58 75 50/60 1S73130-26 220-240 0.58 75 50/60 1S73135 120 1.50 100 50/60 1SP73230 220-240 12 3175 50/60 1SP73230-26 220-240 12 3175 50/60 1SP73235 120 15.0 1720 50/90 1SP73235-60 120 15.0 1720 50/60 1SP73238 208 14.5 2972 50/60 1SP73238-60 208 14.5 2972 50/60 1

Temperature Range for Hot Plates and Stirring Hot Plates104°F - 1004°F (40°C - 540°C)Exception: 120 volt 4-place models - maximum temperature 698°F (370°C)

Stirring Speed Range for 4-place Stirrers and Stirring Hot Plates60 -1200 rpm

Environmental Parameters for all UnitsAmbient Temperature: 17°C - 27°C (63°F - 81°F) Exception: stirrers; see note.Relative Humidity: 20% - 80% (non-condensing)

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General OperatingSpecifications

Note12” x 12” 4-place stirrers are suitable for use in a 37°Cnon-condensing incubator or in a cold room at -4°C.

Replacing the Power Board andor the Logic Board

1. Unplug unit, turn unit upside down andremove screws from bottom.

2. Open unit. Locate power board andlogic board (see photo).

3. The power board and the logic boardwill have to be removed together as aset by unscrewing the metal bracketattaching the two boards to the bottommetal plate. In order to gain access tothe power and logic boards, it is neces-sary to remove the front display panel ofthe unit.

4. Remove the cables from the displayboard.

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Maintenance and Servicing

MIRAK Interior

WarningDisconnect from the powersupply prior to maintenanceand servicing.

Refer servicing to qualifiedpersonnel.

5. Note the position and color of wiresand cable connected to thepower/logic board assembly, payingparticular attention to the position ofthe black wires connecting each ofthe four stirring motors to the boards.

6. Disconnect wires attached to thepower/logic board assembly. If youhave a stirrer skip to step 9.

7. On stirring hot plate models note theposition of the wires running from thethermocouple for the top plate.Remove these wires from the logicboard.

8. Gently pull both power board/logicboard assembly 3-4” to gain access tothe lower thermocouple wire for theexternal probe. Detach this thermo-couple wire.

9. At this point you can remove eitherthe logic board or the power boardfrom the assembly by removing thescrews which secure both boards tothe metal bracket running betweenthe two boards, and to the supportposts.

10. Replace either the power board or thelogic board and reassemble the boardto the support posts, and to the metalbracket running between both boards.

11. If you have a stirring hot plate model,slide the assembly in place andsecure the four screws which mountthe bracket for the board assembly tothe metal plate.

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MAINTENANCE AND SERVICING

12. Position the power/logic board assemblyin place and secure the four screwswhich mount the bracket for the boardassembly to the metal plate.

13. Reconnect all wires and cables andreassemble the front display panel.

14. If the logic board was replaced, locatethe jumper wire at position J3 on thelogic board and move this jumper wireto position J5 on the logic board.

15. Proceed to the set-up procedure. (Thisprocedure is not necessary if only thepower board was replaced, and is alsonot necessary when replacing the logicboard in stirrers.)

Replacing the Display Board1. Unplug unit, turn unit upside down and

remove screws from bottom.

2. Open unit. Locate display board behindthe front panel of the unit.

3. Note the position of the blue stripe run-ning along the bottom of the cable con-nected to the board.

4. Disconnect the cable from the board.

5. Loosen the nuts and remove board fromfront panel.

6. Replace board, reconnecting cable asnoted in step 3. Correct positioning ofblue stripe on cable is important forproper functioning.

7. Replace the bottom and secure it withscrews.

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Power Board for stirring hot plate detailing correct placement of wires and cables

Power Board for stirrer detailing correct placement of wires and cables

Replacing the Motors1. Unplug unit, turn unit upside down and

remove screws from bottom.

2. Open unit. Note position and color ofwires and cables connected to the logic,power and display boards.

3. Remove the display board as noted insteps 3 through 5 under “Replacing theDisplay Board.”

4. Remove the logic and power boardassembly as noted in steps 5 through 8under “Replacing the Power and/orLogic Boards.” (It is not necessary toremove the power board or the logicboard from the metal bracket and thesupport posts they are mounted to.)

5. Remove the encoder wheel from themotor which you intend to replace byloosening the hex screw. (Refer to photoand exploded view.)

6. Unclip the bundle of wires. If you have astirring hot plate proceed with step 7. Ifyou have a stirrer skip to step 11.

7. Remove the two fiberglass insulatedheating ELEMENT wires from the powerboard.

8. Note the lower heating ELEMENT wirewhich runs underneath the powerboard/logic board assembly. Pull thiselement wire free from underneath theboard assembly.

9. Locate the upper THERMOCOUPLE

26


wires coming from the probe recepta-cle at the back of the unit and discon-nect these wires from the logic board.

11. Remove the 6 screws which securethe metal plate to the case.

12. Pick up the whole metal plate assem-bly with the power board/logic boardassembly still attached. If you have astirring hot plate model, carefullythread the element wires through theholes in the metal plate.

13. Flip the plate over.

14. Note the distance of the magnetassemblies from the baffle plateunderneath the top plate assembly.

15. Remove the magnet assembly fromthe motor you will be replacing.

16. Remove the two screws holding themotor and replace the motor.

17. Replace the magnet assembly, main-taining the proper distancing from thebaffle plate.

18. Flip the plate over. If you have a stir-ring hot plate model, make sure theelement wires are threaded backthrough the holes in the metal plate.Reinsert screws and tighten the metalplate to the case.

19. Reattach the encoder wheel on themotor which was replaced. Adjust theencoder wheel on the shaft until itfreely rotates, and then tighten thehex screw.

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20. Screw the bracket with the logicboard/power board assembly back ontothe metal plate.

21. Reattach all wires.

22. Replace display board and attachcables.

23. Bundle wires and resecure with tie-straps.

24. Replace bottom and secure withscrews.

Replacing the Top PlateAssembly

1. Unplug unit, turn unit upside down andremove screws from bottom.

2. Open unit. Note position and color ofwires and cables connected to the logic,power and display boards.

3. Remove the display board as noted insteps 3 - 5 under “Replacing the DisplayBoard.”

4. Unclip the bundle of wires.

5. Remove wiring from power board. (Ifyou have a stirrer skip to step 9.)

6. Note the lower heating ELEMENT wirewhich runs underneath the powerboard/logic board assembly. Pull thiselement wire free from underneath theboard assembly.

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7. Locate the top plate THERMOCOU-PLE wires attached to the logic board.Detach these thermocouple wiresfrom the logic board.

8. Remove the THERMOCOUPLE wirescoming from the probe receptacle atthe back of the unit and disconnectthese wires from the logic board.

9. Locate the screws holding the topplate assembly and attach to thecase. You can access the screwsthrough the four holes in the metalplate or remove the metal plate andthen unscrew the top plate assembly.

10. Replace top plate assembly andattach to the case.

11. If you removed the metal plate,replace it, making sure the thermo-couple and element wires comethrough the metal plate. Insert screwsand tighten the metal plate back intoplace.

12. Reattach the logic board/power boardassembly.

13. Adjust the encoder wheels for eachmotor so each rotates freely throughthe optical pick-up slots on the logicboard. Each black slot should projectno further than the holes in the outerperimeter of each encoder wheel.

14. Reconnect wires and cables to thepower/logic board assembly and putthe display board back into position,reconnecting cables.

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15. Bundle wires and resecure with a tie-strap.

16. Replace bottom and secure withscrews.

17. Proceed to set-up procedure.

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Logic Printed Circuit Board

NoteThe set-up procedure shouldbe followed whenever the topplate assembly or the logicboard is replaced in yourMIRAK 4-place stirring hotplate. The set-up procedure isnot necessary when replacingthe top plate or the logic boardin the stirrers.

Set-Up Procedure1. Place a 500 ml flask with 300 ml of

water on the top plate. Place a stan-dard laboratory thermometer (do notuse the probe for this procedure) 1/2”above the bottom of the flask.

2. Turn the unit on and set the tempera-ture at 70°C. Allow the unit to operateat this temperature for five hours.

3. At the end of five hours note the tem-perature measurement on the ther-mometer and subtract 44° from thethermometer reading to determine theabsolute value. Write this numberdown, you may need to refer to it instep 9. If the absolute value is zero±3, your unit is within tolerance andyou do not need to continue. If yournumber exceeds zero ±3 continuewith steps 4 - 13. If the absolute valueof this difference is greater than ±20from zero, return the unit toBarnstead|Thermolyne for evaluation.

4. Turn the unit off, unplug the cordsetfrom the power source and allow thetop plate to cool.

5. Once the top plate is cool, turn theunit off and remove the bottom cover.If your unit is a stirring hot plate youshould also unscrew the bracket hold-ing the logic board/power boardassembly from the metal plate at thistime. (Refer to the instructions in thismanual for disassembling and remov-ing the logic board.)

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6. Locate the black plastic jumper on thelogic board at position J3. (See the illus-tration of the Logic Printed Circuitboard.) Remove the jumper and secureit across both pins at position J5. If youcannot locate the jumper, contactBarnstead|Thermolyne.

7. Reattach the logic board bracket onyour stirring hot plate model and realignthe pickup slot with the encoder wheel(refer to the instructions in this manualfor reassembling the logic board withthe encoder wheel). Screw the bottomcover back on, plug the unit into thepower source and turn the power switchto the ON position.

8. Push the heat knob once. The digit onthe far right side of the temperature dis-play will get brighter. This display mayread something other than zero. TheHOT light may be on or off which indi-cates whether the number on the dis-play is positive or negative. The numberon the display is positive if the HOT lightis on and negative if the HOT light is off.

9. Refer to the number (absolute value cal-culated) that you noted in step 3. If thatnumber was greater than zero + 3, turnthe knob CLOCKWISE, counting eachclick of the knob until you haveadvanced the knob the same number ofpositions as the number you calculatedin step 3, then turn the knob one addi-tional click. (The knob is is detented soyou can feel a click at each one degreeposition on the knob. Do not turn theknob a full rotation). If the number yourecorded in step 3 was more than zero

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NoteThe temperature display willread 888 and then 000. ThePROBE, SET, TOP and HOTlights will all be illuminated.

minus 3, turn the knob COUNTER-CLOCKWISE, counting each click ofthe knob until you have advanced theknob the same number of positions asthe number you calculated in step 3,and then one additional click.

10. Push the heat knob again. ThePROBE, SET and TOP lights will nolonger be illuminated.

11. Turn the power switch to the OFFposition, unplug the cordset from thepower source, and allow the top plateto cool completely.

12. Remove the bottom cover again andmove the black plastic jumper on thelogic board from position J5 to J3.

13. Replace the bottom again. The unit isnow within tolerance and no furtheradjustment is necessary until the topplate assembly or the logic board isremoved again.

Calibrating the ProbeTemperature InputTo verify the temperature reading of theprobe, insert a calibrated thermometer into asolution you are heating on the stirring hotplate. When the thermometer has stabilized,record the temperature readings given byboth the thermometer and by the probe asindicated on the MIRAK display.

To calibrate the probe:1. Unplug unit, turn unit upside down

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and remove screws from bottom.

2. Open unit. Locate the logic board. (Seeillustration of the interior of unit or theexploded view.) Move the jumper posi-tion J3 to position J5. For series 732units, you must remove jumper J4 if itexists.

3. Replace the bottom of the unit and turnthe unit over.

4. Calculate the necessary correction forthe probe using the following equation:

Probe Error = (displayed temperature) -(actual temperature measured by othersource)

Correction = 350 - Probe Error (if theerror is negative, the correction is >350)

5. Turn the unit on. The display will show“888” and then “000.” The HOT,PROBE, SET and TOP LED’s will be on.Push the heat knob once. The digit onthe far right side will get brighter.

6. Turn the heat knob clockwise until thedisplay shows the correction calculatedabove. Push the heat knob again. TheSET, TOP, and PROBE LED’s will goout. The correction will remain on thedisplay.

7. Unplug unit, turn unit upside down andremove screws from bottom. Movejumper J5 to J3. For series 732 units,replace jumper J4 if necessary.

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NoteThe Maximum error is ±10.Thus the correction must bebetween 340 and 360.

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Troubleshooting

Problem Solution

Unit is not operating at all. Check power.Replace circuit breaker on power switch.

Unit is stirring or heating but no lights Check cable on display board.are lit on the display.

Only the power light is lit on the display. Check ribbon cable connection from the powerboard to the logic board. It may be upside down.Replace display board.

Some digits of the display are not lit. Replace display board.

Display does not increase or decrease Check ribbon cable from knob to logic board. when knob is turned. Replace ribbon cable from knob to logic board.

Replace logic board.Replace encoder switch(es) on knob(s).

Speed or temperature display does not Check ribbon cable from knob to logic board.change when knob is pushed. Replace logic board.

Unit does not stir. Check to see if something is interfering with the motor, preventing it from spinning.Replace power board or logic board.Replace motor.

Unit does not heat. Check heating element. If resistance across element is greater than 100Ω, replace element. Check connection of wires from element to power board.Check triac located on bottom cover of unit.Replace power board or logic board.

Display is reading erratic top plate Replace top plate assembly.temperature.

Display is reading erratic solution Replace probe.temperature.

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Exploded Views

4-place Stirring Hot Plate

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EXPLODED VIEWS

4-place Stirrer

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Replacement Parts

To ensure your safety and for proper operation, the ceramic top plates for hot plates andstir plates are only sold as complete assemblies. This assembly includes the ceramic top,element, thermocouple, insulation, baffle plate and 2 ceramic top holders.

Key Number Part Number Unit Size Unit Voltage Description1 EL732X1B 12” 120V Stir Plate Top Assembly

EL732X2B 12” 220-240V Stir Plate Top AssemblyEL732X3B 12” 208V Stir Plate Top AssemblyPT732X1 12” 100-240V Stirrer Top Plate Only

2 CV730X2 12” 120-240V Clear Plastic Cover3 KBX727X1A 12” 120-240V “Heat” Knob for heating units

KBX727X2A 12” 120-240V “Stir” Knob for stirring units4. MT847X1A 12” 100-120V Motor (13” leads)

MT847X2A 12” 100-120V Motor (8” leads)MT847X3A 12” 208-240V Motor (13” leads)MT847X4A 12” 208-240V Motor (8” leads)

5 Display Printed Circuit Boards: (Front of Unit)PC725X4A 12” 100-120V StirrersPC730X1A 12” 100-240V Stir Plates

6 Logic Printed Circuit Boards: (Center of Unit)PC731X4A 12” 100-240V StirrersPC732X2A 12” 208-240V Stir Plates

7 Power Supply Printed Circuit BoardsPC731X1A 12” 120V StirrersPC731X2A 12” 220-240V StirrersPC731X3A 12” 100V StirrersPC732X1A 12” 120V Stir PlatesPC732X4A 12” 208V Stir PlatesPC732X3A 12” 220-240V Stir Plates

Not Listed Additional Replacement PartsPart Number Unit Size Unit Voltage DescriptionSWX140 12” 100-240V Front SwitchSWX104 12” 100-240V Circuit Breaker Switch StirrersSWX141 12” 100-240V Circuit Breaker Stir Switch PlatesAccessory Thermocouple Probes: (Used with all voltages)TC727X2 7.874” sheath Teflon For corrosive solutionsTC732X1 6.000” sheath Stainless steel For general purpose useTC732X2 10.000” sheath Stainless steel For general purpose useTeflon Coated Stir Bar: (Used with all voltages)ZSX65A 2” bar Teflon coated

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Ordering Procedures

Please refer to the Specification Plate for the complete model number, serial number, andseries number when requesting service, replacement parts or in any correspondence con-cerning this unit.

All parts listed herein may be ordered from the Barnstead|Thermolyne dealer from whomyou purchased this unit or can be obtained promptly from the factory. When service orreplacement parts are needed we ask that you check first with your dealer. If the dealercannot handle your request, then contact our Customer Service Department at319-556-2241 or 800-553-0039.

Prior to returning any materials to Barnstead|Thermolyne Corp. , please contact ourCustomer Service Department for a “Return Goods Authorization” number (RGA). MaterialReturned without an RGA number will be returned.

Barnstead|Thermolyne Corporation warrants that if a product manufactured byBarnstead|Thermolyne and sold by it within the continental United States or Canadaproves to be defective in material or construction, it will provide you, without charge, for aperiod of ninety (90) days, the labor, and a period of one (1) year, the parts, necessary toremedy any such defect. Outside the continental United States and Canada, the warrantyprovides, for one (1) year, the parts necessary to remedy any such defect. The warrantyperiod shall commence either six (6) months following the date the product is sold byBarnstead|Thermolyne or on the date it is purchased by the original retail consumer,whichever date occurs first.

All warranty inspections and repairs must be performed by and parts obtained from anauthorized Barnstead|Thermolyne dealer or Barnstead|Thermolyne (at its own discre-tion). Heating elements, however, because of their susceptibility to overheating and contam-ination, must be returned to our factory, and if, upon inspection, it is concluded that failure isnot due to excessive high temperature or contamination, warranty replacement will be pro-vided by Barnstead|Thermolyne . The name of the authorized Barnstead|Thermolynedealer nearest you may be obtained by calling 1-800-446-6060 (319-556-2241) or writingto:

Barnstead|ThermolyneP.O. Box 797

2555 Kerper BoulevardDubuque, IA 52004-0797

USAFAX: (319) 589-0516

E-MAIL ADDRESS: [email protected]

Barnstead|Thermolyne’ s sole obligation with respect to its product shall be to repair or (atits own discretion) replace the product. Under no circumstances shall it be liable for inciden-tal or consequential damage.

THE WARRANTY STATED HEREIN IS THE SOLE WARRANTY APPLICABLE TOBarnstead|Thermolyne PRODUCTS. Barnstead|Thermolyne EXPRESSLY DISCLAIMSANY AND ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING WAR-RANTIES OF MERCHANTABILITY OR FITNESS FOR USE.

One Year Limited Warranty

9001ISOREGISTERED

Barnstead|Thermolyne2555 Kerper Blvd.P.O. Box 797Dubuque, IA 52004-2241Phone: 319-556-2241 800-553-0039Fax: 319-589-0516E-Mail Address: [email protected]

mirak™ 4-place stirrers and stirring hot plates mir… · 28-05-1999 · your thermolyne...

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