SERVICE MANUAL - Direct Pesage
Contents
1. 1 5 TEST MASSES REQUIRED The masses required to test the Ohaus Trooper Scales must meet the requirements of ASTM Class 4 Tolerance The mass values are listed in Table 1 1 TABLE 1 1 TROOPER CALIBRATION MASSES TR3RS 1 2 3kg 2 amp 3kg TR6RS 2 4 6kg 4 amp 6 kg TR15RS 5 10 15kg 10 amp 15 kg TR30RS 10 20 30kg 20 amp 30 kg Cal in Ib Span cal choices Linearity cal fixed 2 4 6 lb 4 amp 6 lb 5 10 15 Ib 10 amp 15 Ib 10 20 30 Ib 20 amp 30 Ib 20 40 60 Ib 40 amp 60 Ib CHAPTER 1 INTRODUCTION 1 6 SPECIFICATIONS Complete specificatons for the Ohaus Trooper Scales are listed in Tables 1 2 and 1 3 When a scale has been serviced it must meet the specifications listed in the tables Before servicing the scale determine what specifications are not met TABLE 1 2 TROOPER MODEL SPECIFICATIONS Standard Models TRSRS TReRS TRISRS TR3ORS Default Capacity X Readability Ib 60lb X 0 016 Default Capacity X Readability kg 30kg X 0 005kg Default Capacity X Readability 300000 X 5g Default Capacity X Readability oz 96002 X 0 202 NTEP Capacity X Readability Ib 60lb X 0 02Ib NTEP Capacity X Readability kg 30kg X 0 01kg NTEP Capacity X Readability 0 300009 X 10g NTEP Capacity X Readability oz 96002 X 0 502 Linearity g 50 Item Number TR3RS 2EO TRGRS 2EO TRI5RS 2E0 TR3ORS 2EO Default capacity and readability are dependent on calibration unit selected The table above assumes tha2. 3 Check the Power Cord for broken or damaged insulation 4 Make a visual inspection for faulty connectors wiring and loose hardware 4 2 TESTING Before servicing the Trooper scale an operational test and various performance tests should be made to ascertain whether or not the scale meets specifications Turn the scale on and allow it warm up for at least one hour before performing these tests Make sure the test area is free from drafts and the surface that the scale rests on is level and vibration free The masses used for the performance tests and adjustments must meet or exceed ASTM Class 4 Tolerance 4 2 1 Operational Test 1 Connect the AC Adapter into a suitable power source and connect to the scale 4 2 1 1 Segment Display Test 1 Turn the scale on all segments are enabled and displayed breifly followed by a software revision number This is a segment display test Figure 4 1 is a full display test D DDDODDILz Y Y BAT Figure 4 1 Segment Displays 4 1 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 2 Menu Structure Programmable features of the Trooper Scales are contained in menus which are accessed through the front panel control switches Figure 4 2 illustrates the menu structure CALIBRATION Reset N or Y Reset SETUP Lock 2 227 to Factory Settings to Factory Settings Switch set SPAN Y yo E Yes or No ON OFF Faro Averaging Level HI or LO Baud Rate set READOUT LIN Y 2 18 100 1200 240
3. diagnosis diagnostics chart and error code table Chapter 4 Maintenance Procedures Contains preventive maintenance procedures performance tests and adjustments repair procedures service mode procedures and calibration procedures Chapter 5 Drawings and Parts List Contains exploded view of Trooper Scale identifying all serviceable replacement components with parts list Before servicing the scale you should be familiar with the Instruction Manual which is packed with every Trooper Scale 1 3 SERVICE FACILITIES To service the Ohaus Trooper Scale the service area should meet the following requirements DO NOT SERVICE the scale Next to open windows or doors causing drafts or rapid temperature changes Near air conditioning or heat vents Near vibrating rotating or reciprocating equipment Near magnetic fields or equipment that generates magnetic fields unlevel work surface Allow sufficient space around the instrument for ease of operation and keep away from radiating heat sources 1 2 CHAPTER 1 INTRODUCTION 1 4 TOOLS AND TEST EQUIPMENT REQUIRED In order to properly service the Ohaus Trooper Scales a standard electronic tool kit is required No special tools and test items are required 1 4 1 Special Tools None required 1 4 2 Standard Tools and Test Equipment 1 Digital Voltmeter DVM Input impedance of atleast 10 megohms in the 1 Volt dc position 2 Standard Electronics tool kit
4. selection to the desired value When the desired selection has been chosen and the masses are available you are ready to begin the calibration routine Coon wu armi 3 un LM x o kg Gross Brutto NOTE If the Scale is to be used for legal for trade applications it must be calibrated and the LFT Lock Switch must be set ON to lock out the menus Refer to paragraph 4 2 6 for sealing for legal for trade use Procedure SPAN CALIBRATION With the Scale ON press and hold the G N T MENU button until MENU is displayed When you release the G N T MENU button CAL is displayed If the display shows SETUP read the section on turning off the Calibration Lock Switch or check the settings for legal for trade Press G N T MENUbutton SPAN Y is displayed Press G N T MENU button C is displayed The scale MUST be stable during this period and is establishing a zero point After a few seconds the requested weight value is displayed Place the indicated mass on the platform Keep the platform stable during this period The sample illustration indicates a 15kg scale If atthis point you are uncertain of the process or if the correct weights are not available the calibra tion routine can be aborted by pressing the PRINT UNITS button or by turning the scale off by press ing and holding the ON ZERO OFF button Press G N T MENU button C is displayed while the Scale stores the reading and then
5. the bottom housing about two to three inches Reach under the upper housing from the front and carefully disconnect the flexible cable from the PC board 5 Remove the connector plugs from connectors J6 and J7 from the PC Board which is the battery and external power wires See Figure 4 8 TO LOADCELL TO RS232 s cool GE 0000000 Wi JUMP 2 JUMP 1 TO BATTERY TO EXTERNAL POWER J5A TO KEYPAD HE E S Figure 4 8 Connector Locations 4 16 CHAPTER 4 MAINTENANCE PROCEDURES 4 3 2 Replacing the PC Board Cont 6 Carefully remove the wires coming from J10 which is the RS232 connector and J4 which is used to connect the loadcell See figure 4 9 for wire color and locations RS232 CONNECTOR PINS 5 23 TO LOAD CELL GREEN IL D WHITE RED YELLOW ooo ddn 0000000 J JUMP2 Wi exe ele sia Lei SEN GND SEN JUMP 1 Figure 4 9 RS Connector and Loadcell Connector Wiring 7 Remove the four corner screws on the PC Board 8 Replace the PC Board and install the four screws previously removed 9 Replace the color coded wiring for connectors J4 and J10 Check color coded wiring is correctly installed 10 Replace the connectors to J6 and J7 on the PC Board 11 Position the upper housing in place over the scale and connect the flexible cable from the keypad to the socket on the PC board 12 Reassemble the scale by replacin
6. to the name of the components identified in the exploded view drawing 2 2 LOADCELL THEORY The Loadcell assembly used in Trooper balances is part of a Spider Assembly The Spider Assembly consists of two spider shaped brackets in which the Loadcell is mounted in between in a sandwich fashion The Spider Assembly holds the Loadcell in proper alignment with preadjusted down stop screws which are locktited The bottom half ofthe Spider Assembly is mountedto the base ofthe scale The upper half of the Spider Assembly forms the sub platform for the scale The platform assembly is mounted directly to this Loadcells may not be ordered as a replacement part since they are part of the Spider Assembly For electrical components refer to schematic diagram Figure 5 2 For mechanical components refer to Figure 5 1 One basic type of Loadcell is used in the Trooper balances The Loadcell contains four Strain Gauges in a full bridge configuration The full bridge has two Strain Gauges mounted on top of the Transducer and two mounted on the bottom A temperature compensation sensor is also mounted on the top of the Loadcell The Loadcell consists of an aluminum beam with 4 Strain Gauges bonded at the hinged areas thinnest part of the beam Two of the Strain Gauges are located on top of the beam and two on the bottom These 4 electrical strain gauges are wired to form a Wheatstone bridge When aloadis placed on the beam it bends atthe hinged areas The bending
7. 0 4800 Lockout Switch set RA Stability Level 9600 19 200 ON OFF Calibration Unit 0 5 1 or 3 2 DORMI Parity Bit set PRINT Lockout f g switch NONE Even or Odd Switch set F Capacity cannot ON or OFF ON OFF be changed Data Length set Se Unit kg switch 7or8 CALIBRATION Graduation Size or OFF L GE ockout Switch set 001 002 005 Stop Bits set ON OFF Unit Ib switch 10r2 XS Calibration Point ON or OFF 5kg 10kg Auto Print Save setings Unit oz switch ON OFF cont On Save Settings ON or OFF Stability See Note Auto Zero Tracking Interval 0 5 1 or 3 1 to 3600 seconds NOTE FOR SHADED AREA Whichever unit is used for calibration is auto Timer Stable matically set to ON and does not appear ON 5 min or OFF ON or OFF inthe READ menu Retain Zero Data ON or OFF Backlight ON OFF or AUTO EP Service mode ON or OFF Save Settings Save Settings Press G N T MENU to enter the display submenu or select a displayed setting Press PRINT UWITS to change the displayed submenu or setting Factory default settings are shown in underlined and boldface type When CAL switch on the circuit boardis inthe LFT position all ofthe menus can be reached except CALIBRATION Menu but only the submenus which are marked can be setup see menu structure Figure 4 2 Trooper Scale Menu 4 2 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 3 Trooper Switc
8. 2 1 2 3 2 Power Monitor IDEA eet decide dls ee 2 1 2 33 MIGIODIOGOSSOF EE 2 2 MEESI EE 2 2 230 Memory Storage neni sca peer 2 2 2 3 6 LCD Display Information see 2 2 2 3 7 Display ON Ol E 2 2 RER le TEE 2 2 2 3 9 Load Cell Excitation Voltage AAA 2 2 2 3 10 5232 Operation EE 2 2 CHAPTER 3 TROUBLESHOOTING 3 1 Jolie 3 1 32 Guide nase Dane 3 1 9 21 WR Le e 3 1 EE M 3 3 CHAPTER 4 MAINTENANCE PROCEDURES 4 1 Preventive Maintenance Ee kde Eegeg 4 1 4 1 1 Preventive Maintenance 4 1 42 Testing essen 4 1 4 2 1 Operational LES Laa dd od 4 1 4 2 1 1 Segment Display Test i i pert n tero eng opns 4 1 4 2 2 Menli Sirlel re EE 4 2 4 2 3 Trooper Switch ei 4 3 4 2 4 Trooper Scale Menu 4 3 4 2 4 1 How to Enter the Menus 42 2 20444 2 4 3 4 2 4 2 How to Select a Specific 4 3 4 2 4 3 How to Enter an Individual 4 4 4 2 4 4 How to Enter an Individual Menu Item 4 4 4 2 4 5 How to Save and Store an Individual Menu ltem 4 4 TABLE CONTENTS Cont CHAPTER 4 MAINTENANCE PROCEDURES Cont Page 4 2 4 6 How to Quit the MENUS use SCENE 4 4 212 5 Caldo KEEN 4 4 4 2 6 Legal for Trad
9. 2033 USA Tel 973 377 9000 Fax 973 593 0359 In the United States call toll free 800 526 0659 between 8 00 a m and 6 00 p m EST 3 1 CHAPTER 3 TROUBLESHOOTING TABLE 3 1 DIAGNOSTIC GUIDE SYMPTOM PROBABLE CAUSE S REMEDY Unit will not turn on Cannotzero Scale or will not zero when turned on Center of Zero display indi cator erratic or does not ap pear with no load on scale platform Cannot display weight in de sired weighing unit Adapter not plugged in or prop erly connected Batteries dead or not properly installed Membrane switch failure Load on scale exceeds allow able zero entered in ZERO parameter of Setup menu Retain Zero Data is enabled in scale menu Scale platform motion or dis turbances exceed center of zero criteria Desired unit not set to ON in Read menu Check power cord connec tions Make sure adapter connec tor is plugged all the way into the Scale Check battery connector Check orientation of the bat teries Replace batteries Check functions of mem brane switch Remove load on scale to less than entered zero Change allowable zero in ZERO parameter of Setup menu Normal operation when this feature is disabled Remove disturbances or reduce motion Increase AZT level in read out menu Increase averaging level in readout menu Enable desired unit in Readout menu Conversion too large typi cally in g CHAPTE
10. HROUGHOUT THE PROCEDURE As close to full capacity as possible while allowing the 100g weight to read 4 11 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 7 3 Linearity Test Cont Before beginning Perform calibration Preliminary Weighings Using the Load 3 and Load 4 weight values Table 4 3 perform some preliminary weighings and make sure the display returns to zero after weighing 1 Place Load 3 on the center of the Platform read the displayed weight then remove Load 3 If the display does not return to zero press ON ZERO OFF and repeat this 2 Repeat step 1 using Load 4 After performing preliminary weighings proceed with checking Linearity If the scale does not return to zero it must be repaired Test 1 Place the reference mass on the center ofthe Platform and record the exact value all decimal places displayed 2 Remove the reference mass and verify that the display returns to zero If it does not disregard the reading press ON ZERO OFF to rezero the display and take that reading again See note above 3 Place Load 1 on the center of the Platform and press ON ZERO OFF 4 Add the reference mass to the Platform and record the exact value displayed 5 Remove the reference mass and verify that the display returns to zero If it does not disregard the reading press ON ZERO OFF to rezero the display and take that reading again NOTE If after several attempts the display fails to return to zero a repeata
11. NITS button the computer and or a printer should indicate the mass value NOTE Printcommands entered through the com puter are temporary When the scale is turned off it will return to scale menu settings when turned on again 4 14 CHAPTER 4 MAINTENANCE PROCEDURES 4 3 REPAIR PROCEDURES This section describes how to change individual components of the Trooper scales When doing this please refer to the exploded view drawings and spare parts lists in section 5 Important after replacing components a functional check of the scale must always be carried out 4 3 1 Replacing the Keypad Membrane The keypad membrane is affixed to the upper housing of the scale To replace the keypad the scale must be disassembled to gain access to the keypad connections 1 Remove power from the scale 2 Carefully lift and remove the platform from the scale You will find that one rubber foot remains attached to the platform this is normal This is used to ensure the platform is properly located on the weighing loadcell when replaced Turn the scale over on it s bottom and remove the six screws which hold the upper housing CAUTION Use care in the next step as the keypad wiring is attached to the PC board 4 Turn the scale over again to its normal upright position and carefully lift the upper housing from the bottom housing about two to three inches Reach under the upper housing from the front and carefully disconnect the flexible cable from t
12. O OFF button to return the reading to zero Move the mass halfway to the rear of the Platform and note the reading Move the mass halfway between the center and the left edge front of the Platform and note the reading Repeat this test for the right edge position and note the reading Move the mass halfway to the front of the Platform and note the reading Note any differences in the displayed weight reading at all positions Maximum allowable change is per Table 4 2 for each of the listed scales four positions Move back to center and tare if neccessary after each reading MASS LOCATIONS CN 188 Figure 4 6 Off Center Load Test Mass Locations 4 2 7 3 Linearity Test The Linearity test is used to determine the linearity of the scale throughout its operating range and is in accordance with the specifications listed in Tables 1 2 and 1 3 NOTE The scale must pass the Off Center Load test and Repeatability Test before the Linearity Test is performed This test is used to determine the linearity of the scale throughout its operating range Table 4 3 lists the suggested masses to be used for checking linearity on each scale model Ifthe unitfails the linearity test checkthe alignment of the transducer and re assemble Ifthetransducer has been replaced carefully check the alignment TABLE 4 3 LINEARITY TEST MASSES ER Er 2 25kg 4 5kg 22 5kg TE og All masses are nominal values BE CERTAIN TO USE THE SAME REFERENCE MASS T
13. OF ILLUSTRATIONS FIGURE NO TITLE PAGE NO 2 1 Trooper Block Diagramm 22 22 40 Bea 2 3 4 1 Segment Display S zes 4 1 4 2 Trooper Scale Men EE 4 2 4 3 Lock SWICK ooi EEN 4 9 4 4 Sealing the Scale with a Lead 22 4 9 4 5 Sealing the Scale with a Paper 4 9 4 6 Off Center Load Test mass 4 11 4 7 RS232 Interface Pin Connections un 4 13 4 8 Connector LOCATIONS iiie PRO Ete bar dur te 4 16 4 9 RS Connector and Loadcell Connector Wiring 4 17 4 10 Trooper Component Locations 4 19 5 1 Exploded View of Trooper Scale 5 2 5 2 Trooper Scale Interconnection 5 4 5 3 Keypad Wiring Diagram ee 5 4 CHAPTER 1 INTRODUCTION 1 1 OVERVIEW OF CONTROLS AND DISPLAY FUNCTIONS eler neon Display LCD display indicates weight modes and setup information Center of Zero LCD indicator prompt indicates center of zero when within 0 25d Gross LCD indicator prompt indicates gross weight Net LCD indicator prompt indicates net weight Tare LCD indicator prompt indicates tare weight ON ZERO OFF button Turns Scale on or off Secondary use provides zero function Print Units bu
14. Ohaus Corporation 19A Chapin Road Pd Box 2033 Pine Brook NJ 07058 2033 USA OHAUS www ohaus com TROOPER SCALE SERVICE MANUAL Ohaus Corporation 19A Chapin Road P O Box 2033 Pine Brook NJ 07058 2033 973 377 9000 Ohaus Corporation 19A Chapin Road Box 2033 Pine Brook NJ 07058 2033 USA OHAUS www ohaus com SERVICE MANUAL Trooper Scale The information contained in this manual is believed to be accurate atthe time of publication but Ohaus Corporation assumes no liability arising from the use or misuse ofthis material Reproduc tion of this material is strictly prohibited Material in this manual is subject to change Copyright 2001 Ohaus Corporation all rights reserved Registered trademark of Ohaus Corporation TABLE 5 CHAPTER 1 INTRODUCTION Page 1 1 Overview of Controls and Display Functions 1 1 1 2 ORIENT e ir oct C aa ca dest 1 2 1 3 Service Facilities mette DT 1 2 1 4 Tools and Test Equipment 1 3 TAT Special EE 1 3 1 4 2 Standard Tools and Test 1 3 135 Test Masses Reduifed a ee 1 3 1 6 eelere 1 4 CHAPTER 2 THEORY OPERATION 2 1 Trooper Theory of Operation EE 2 1 Ne ele ER EE 2 1 2 3 Printed Circuit Board Theory EE 2 1 2 3 1 Power Supply eure
15. R 3 TROUBLESHOOTING TABLE 3 1 DIAGNOSTIC GUIDE Cont SYMPTOM PROBABLE CAUSE S REMEDY RS232 not working RS232 communication param Verify communication pa eters set up incorrectly rameters Improper or loose cable connec Check cable connections tions Unable to calibrate unit Software Lockout switch setto ON Set LCL to OFF in the and Lock Switch on the circuit LocSW menu and set Lock board set to open position Switch on the circuit board to ON position Incorrect value for calibration Use correct calibration mass mass 3 3 ERROR CODES This scale is equipped with software which will display an error condition when it occurs When a problem occurs using the scale the display will indicate an error code Review the listed codes and follow instructions to correct the problem Table 3 2 Error Codes describes the various error codes which can appear on the display and specifies the probable reason and remedy TABLE 3 2 ERROR CODES Indication Problem LoBat Is indicated when batteries are weak Approximately 20 minutes of operating time remain Replace batteries as soon as possible Error 1 Indicates an overload condition Remove overload condition Error 2 Indicates an underload condition Error 7 EEPROM data incorrect Check scale settings Error 14 Zero exceeds ZERO and cannot be zeroed Error 21 Calibration data does not match current full scale Grad and Cal Point settings Settings mus
16. bility problem is indicated and the scale must be serviced by an Ohaus Product Service Specialist 6 Repeat steps 3 through 5 using Load 2 Load 3 and Load 4 as applicable 7 Compare the reference weight readings They should agree per table 4 2 4 12 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 8 RS232 Interface Test The RS232 Interface in the Trooper scale can have its performance monitored using an external printer or computer connected to the scale The RS232 Interface is a bi directional interface which enables the scale to communicate with a printer or computer equipped with an RS232 serial port An Print menu is in the scale This menu enables various parameters such as Baud rate Data bits Stop Bits and Parity to be set in the scale The Print menu provides communication parameters which can be set to accommodate external printers or computers It contains eight submenus Reset Baud Rate Parity Bit Data Bits Stop Bits Auto Print Interval Stable and save settings which enable youto program RS232 port parameters Refer to Print menu and make sure all communications parameters are properly set 4 2 8 1 Connecting the RS232 Interface When the interface is connected to a computer two way communication between the computer and scale is possible using the commands outlined in the RS232 Command Table 4 4 See Figure 4 7 for connections Whenthe scale is connected directly to a printer displayed data can be output at any time by sim
17. changes the resistance of the Strain Gauges and the resulting resistance output from the Wheatstone bridge is proportional to the load Six Down Stop screws which are part of the upper Spider Assembly engages and limits the external load at slightly over full load capacity and limits the bending of the beam preventing damage due to overloading The Spider Assembly does not contain up stop screws which protects the Transducer assembly from exceeding maximum upward movement 2 3 PRINTED CIRCUIT BOARD THEORY See figure 2 1 2 3 1 Power Supply Circuit U12 Power to the scale is supplied by a 9 V dc 500mA Power Adapter to connector J7 or by 6 C size Alkaline batteries Power is regulated through U12 3 terminal positive voltage regulator to output a regulated 5 V dc which supplies the board 2 3 2 Power Monitor Circuit 09 Battery voltage is monitored by a power monitor circuit U9 When the battery voltage goes low to a preset point a reset signal Low Bat is sent from the power monitor circuit to the microprocessor U7 The microprocessor activates the display which indicates a low battery voltage condition CHAPTER 2 THEORY OPERATION 2 3 PRINTED CIRCUIT BOARD THEORY Cont 2 3 3 Microprocessor 07 The microprocessor U7 contains a built in RAM ROM and an LCD driver Crystal Y1 operates ata frequency of approximately 4 00 MHz andis used to control the frequency of the microprocessor The microprocessor provides serial data to the LCD dis
18. de LFT Operation and Sealing Legalfor Trade LFT operation is possible through a LFT Lock Switch located on the PC board The Scale must be calibrated prior to performing this proceedure Procedure Set up Scale and calibrate After this is done remove power from the Scale Turn the scale over in the position as shown and remove the Lock Switch cover plate Refer to the illustration at the left and notice the position of the LFT switch To lock out the menus E slide the LFT switch to the position shown WEE Replace the Lock Switch cover and housing screw cover The two screws are cross drilled and can accept a wire seal NOTICE The Trooper Scale has been tested and found to comply with Class Ill requirements of NIST Handbook 44 After the Scale has been tested and found to comply with local applicable regulations by a local weights and measures official it may be sealed as follows LEAD AND WIRE SEAL See illustration at left Place wire seal through the holes in the screw and ribs as shown and compress the lead seal in place PAPER SEAL If an audit trail or paper seal will be used place a paper seal over both access covers Figure 4 5 Sealing the Scale with a Paper Seal 4 9 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 7 Performance Tests Accurate performance ofthe Trooper scales is determined by a series of three performance tests dis
19. displays the weight of the mass If the calibration was successful the calibration mass is displayed and the calibration data is saved automatically If unsuccessful refer to the trouble shooting section Remove calibration masses from platform After the calibration routine is complete check the scale again to see if the scale has been accurately calibrated If so return to the lockout menu and restore the calibration software lock to ON 4 6 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 5 Calibration Cont Procedure TURNING CALIBRATION LOCK SWITCH ON To turn the software lock on Press and hold the G N T MENU button until L L MENU appears Release it SETUP appears AL E if already in the main menu skip to the next step Repeatedly press the PRINT UNITS button until LOCSW is displayed Repeatedly press the G N T MENU button until LCLOFF is displayed l f l Press the PRINT UNITS button to scroll through the choices until LCLON appears FI Press the G N T MENU button repeatedly until LLLLIII the scale returns to weighing The scale is now ready for weighing 4 7 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 5 Calibration Cont Procedure LINEARITY CALIBRATION As with span calibration confirm that calibration is really required If required referto page 20 and turn the Calibration Lock Switch off With the Scale ON press and hold the button G N T MENU until MENU is d
20. e LFT Operation LFT Sealing 4 9 42 7 Performance Tests imer reg ao ge ede Que EI MH 4 10 4 2 7 1 Repeatability 2 4 10 4 2 7 2 Off Center Load 402221222 4 11 4 2 7 3 Linearity Testa ous idt een 4 11 4 2 8 5232 Interface Test i Soo ien he ce ES EF T 4 13 4 2 8 1 Connecting the RS232 Interface 4 13 22 9 Print KEE 4 14 4 3 Repair Procedures ek 4 15 4 3 1 Replacing the Keypad Membrane 4 15 4 3 2 Replacing the Board BEE 4 16 4 3 3 Replacing the Spider Assembly Loadcell 4 18 CHAPTER 5 DRAWINGS AND PARTS LISTS 5 1 Drawings and Parts EEN 5 1 5 1 1 Trooper Exploded View er een 5 2 TABLE CONTENTS Cont LIST OF TABLES TABLE NO TITLE PAGE NO 1 1 Trooper Calibration Masses ko 1 3 1 2 Trooper Model Specifications ern eek 1 4 1 3 Trooper General Specifications 1 4 3 1 Bra aaa aaea a 3 2 3 2 Efron Codes iniciado 3 3 4 1 Calibration MASSES EE 4 5 4 2 Types of performance Tests usais ii 4 10 4 3 Linearity Test Masses u nee 4 11 4 4 RS232 COMMANGS 4 14 5 1 Trooper Parts EISE Gt tas 5 3 LIST
21. e When QUIT is reached the next press on the PRINT UNITS button will return to the CALIBRATION or SETUP menu 4 3 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 4 Trooper Scale Menu Operation Cont 4 2 4 3 How to Enter an Individual Menu A short press on the G N T MENU button YES and you can enter a specific menu 4 2 4 4 How to Enter an Individual Menu Item When in any menu a short press on the G N T MENU button YES and you can enter a specific menu item To advance through a given menu make short presses on the PRINT UNITS NO button 4 2 4 5 How to Save and Store an individual menu item When a menu item has been changed once the desired selection is shown make a short press on G N T MENU button Quit appears on the display If NO is selected by pressing the PRINT UNITS button the next menu item appears If yes is selected by pressing G N TMENU StorE appears Pressing the G N T MENU button will store the change and return the scale to a weighing mode If NO is selected the menu change is ignored and the scale is returned to weighing mode 4 2 4 6 Howto Quit the Menus A short press on the PRINT UNITS button NO When in MENU MODE short presses will advance through the menus until QUIT is reached Toquit makea short press onthe G N T MENUbutton StorE appears answer YES to save changes and the scale returns to the weighing mode or NO to ignore changes and return to the weighing mode 4 2 5 Calibration Span calibration ensure
22. etup menu After the desired calibration unit has been chosen advance to the LOCSW menu to turn the calibration lock switch off This software lock is in place to prevent accidental calibration 4 4 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 5 Calibration Cont I1 Procedure TURNING CALIBRATION LOCK SWITCH OFF To turn the software lock off Press and hold the G N T MENU button until MENU appears Release it SETUP appears if already in the main menu skip to the next step Repeatedly press the PRINT UNITS button until LOCSW is displayed Repeatedly press the G N T MENU button until LCL ON is displayed Press the PRINT UNITS button to scroll through the choices until LCLOFF appears Press the G N T MENU button repeatedly until the scale returns to weighing Before calibrating make sure that you have the correct masses available TABLE 4 1 CALIBRATION MASSES 2 4 6kg 5 10 15kg TR30RS 10 20 30kg 2 amp 3kg 4 amp 6kg 10 amp 15 kg 20 amp 30 kg Cal in Ib Linearity cal fixed 4 amp 6lb 10 amp 15 Ib 20 amp 30 Ib 40 amp 60 Ib TR6RS TR15RS TR30RS 5 10 15 Ib 10 20 30 Ib 20 40 60 Ib 4 5 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 5 Calibration Cont For span calibration there are a number of choices for calibration The highlighted number is the default To change the span calibration value read the setup section of the menu In the Setup menu change the CP
23. g the six screws at the bottom of the scale which secure the upper housing 13 Replace the platform on top of the scale 14 After installation check all operations if possible set the original customer settings back into the scale and calibrate the scale 4 17 CHAPTER 4 MAINTENANCE PROCEDURES 4 3 3 Replacing the Spider Assembly Loadcell The Spider assembly is centrally located inside the scale and contains the loadcell See Figure 4 10 This assembly is factory assembled and the downstops are preadjusted There are no adjustments to be made on this assembly after installation 1 2 Remove power from the scale Carefully lift and remove the platform from the scale Turn the scale over on it S bottom and remove the six screws which hold the upper housing CAUTION Use care in the next step as the keypad wiring is attached to the PC board Turn the scale over again to its normal upright position and carefully lift the upper housing from the bottom housing about two to three inches Reach under the upper housing from the front and carefully disconnect the flexible cable from the PC board Carefully remove the wires coming from J4 which is used to connect to the loadcell See figure 4 9 for wire color and locations Remove the four screws holding the Spider Assembly to the bottom housing Lift the Spider Assembly out of the bottom housing and replace with a new Connect the color coded wiring fro
24. h Functions The four button switches located on the right hand side of the scale provide basic operation and menu setups Please read the following information before pressing any of these buttons um BUTTONS PRIMARY FUNCTION SECONDARY FUNCTION ON ZERO Short press Turns scale ON if OFF When scale is ON short press zeros the OFF Long press Turns scale OFF if ON scale PRINT Short press Sends current weight to When in MENU MODE short press NO printer UNITS Long press Changes UNITS G N T Short presses Toggles display between When in MENU MODE short press YES MENU Gross Net Tare if tare value is stored Noactionfor5secs scaledisplay reumsto NET Long press Enter MENU TARE Short press enter TARE 4 2 4 Trooper Scale Menu Operation This section describes the menu operation The menu permits matching the scale to specific weighing needs In the menu you can change the settings of the scale and activate functions The Main Menu contains 6 sub menus Each of the six sub menus are described in detail in the Operating Manual supplied with the scale gt E gt E gt 4 2 4 1 How to Enter the Menus To enter the menus press and hold the G N T MENU button until MENU appears When you release G N T MENU button Setup appears 4 2 4 2 How to Select a Specific Menu A short press on the PRINT UNITS button NO When in MENU MODE short presses will advance to the next menu as shown abov
25. he PC board 5 Onthe upper housing lift up the defective keypad membrane if necessary carefully prying it up with a knife and gently peel it off the upper housing 6 Carefully clean the upper housing keypad area removing all traces of adhesive 7 Peel off the protective film from the new keypad membrane and carefully affix the latter to the upper housing 8 Press the keypad membrane down uniformly 9 Position the upper housing in place over the scale and connect the flexible cable from the keypad to the socket on the PC board 10 Reassemble the scale by replacing the six screws at the bottom of the scale which secure the upper housing 11 Replace the platform on top of the scale 4 15 CHAPTER 4 MAINTENANCE PROCEDURES 4 3 2 Replacing the PC Board The PC Board is located inside the scale towards the front To replace the PC Board it is necessary to disassemble the scale 1 Remove power from the scale 2 Carefully lift and remove the platform from the scale You will find that one rubber foot remains attached to the platform this is normal This is used to ensure the platform is properly located on the weighing loadcell when replaced Turn the scale over on it s bottom and remove the six screws which hold the upper housing CAUTION Use care in the next step as the keypad wiring is attached to the PC board 4 Turn the scale over again to its normal upright position and carefully lift the upper housing from
26. he SEN and EXC for a four wire system 2 3 9 Load Cell Excitation Voltage A six 6 wire interface for the analog load cells is provided at J4 located on the PC board Excitation voltage for the load cells is 5 Vdc 2 3 10 RS232 Operation The RS232 half duplex operation is controlled by the microcontroller U1 MAX 202 Signals supported are RXD TXD and GND There is no handshake interface The serial port may receive the external Tare Zero and Print command in ASCII code CHAPTER 2 THEORY OPERATION 2 3 PRINTED CIRCUIT BOARD THEORY Cont ND ANALOG UC CONVERTER INPUT Ee LCD DISPLAY amp EL PANEL BACK LIGHT BL2 DRIVER BL1 MICROPROCESSOR 5V BATTERY VOLTAGE U7 MONITOR D RS232 DRIVER RXD1 2 5 95232 5V BATTERY 3 Ut 2 3 VOLTAGE L MONITOR 5V DC LOWBAT RXD TXD LOWBAT GND MFG TEST GND arena 1 a BEEPER DRIVE 2 BUZZER e KEYBOARD Gees A BEEPER INPUT 4 5 c3 wi Te MFG s st 1024 oO en U11 Figure 2 1 Trooper Block Diagram 2 3 CHAPTER 2 THEORY OPERATION 2 4 CHAPTER 3 TROUBLESHOOTING 3 1 TROUBLESHOOTING This section of the manual specifies problem areas of the scale which can occur Information is contained to isolate specific problems using Table 3 1 Diagnostic Guide and Table 3 2 Error Codes Follow all directions step by step Make certain that the work a
27. isplayed When you release the G N T MENU button CAL is displayed Press G N T MENUbutton SPAN Y is displayed Press PRINT UNITS button Lin Y is displayed Press G N T MENU button C is displayed The scale MUST be stable during this period and is establishing a zero point After a few seconds thedisplay flashes LIN CP twice and the re quested weight value is displayed The sample illustration indicates a 4kg mid point for a 6kg scale Linearity calibration for Trooper is 0 2 3 and full capacity Place the indicated mass on the platform Keep the platform stable during this period Press G N T MENU button C is displayed The scale MUST be stable during this period and is establishing a zero point After a few seconds the display flashes FULLCP and the requested weight value is displayed Place the indicated mass on the platform and press the G N T MENU button C is displayed If linearity calibration was successful the cali bration mass is displayed and the calibration data is saved automatically If unsuccessful re fer to the troubleshooting section Remove calibration masses from platform After calibration turn the Calibration Lock Switch On NOTE If the Scale is to be used for legal for trade applications it must be calibrated and the Lock Switch must be set to lock out the menus Refer to paragraph 4 2 6 for sealing for legal for trade use 4 8 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 6 Legal for Tra
28. m the loadcell to connector J4 Check that color coded wiring is correctly installed See Figure 4 9 10 Position the upper housing in place over the scale and connect the flexible cable from the keypad to the socket on the PC board 11 Reassemble the scale by replacing the six screws at the bottom of the scale which secure the upper housing 12 Replace the platform on top of the scale 13 After installation check all operations if possible set the original customer settings back into the scale and calibrate the scale 4 18 CHAPTER 4 MAINTENANCE PROCEDURES DC POWER JACK BATTERY BOX RS232 CONNECTOR SPIDER ASSEMBLY FERRITE CORE LOADCELL LOCK SWITCH RS232 CABLE BATTERY BOX LOADCELL amp CABLE POWER CONNECTOR CABLES PC BOARD KEYPAD CONNECTOR LED DISPLAY Figure 4 10 Trooper Component Locations 4 19 CHAPTER 4 MAINTENANCE PROCEDURES 4 20 CHAPTER 5 DRAWINGS AND PARTS LISTS 5 1 DRAWINGS AND PARTS LISTS This section of the manual contains an exploded view schematic diagrams interconnection diagram and a spare parts list for the Trooper scales The exploded view drawing identifies the replaceable parts which can be serviced on the scale in the field NOTE In all cases where a part is replaced the scale must be thoroughly checked after the replacement is made The scale MUST meet the parameters of all applicable specifi cations in this manual If further technical i
29. nformation is needed in the United States call toll free 1 800 526 0659 between 8 00 a m and 4 00 p m EST An Ohaus factory service technician will be available to provide assistance Outside the U S A please contact Ohaus Corporation 19A Chapin Road P O Box 2033 Pine Brook NJ 07058 2033 USA Tel 973 377 9000 Fax 973 593 0359 CHAPTER 5 DRAWINGS AND PARTS LISTS 5 1 1 Trooper Exploded View Figure 5 1 Exploded View of Trooper Scale 5 2 0 Ooooh MIMI hl sch sch sch RI 22 NOTE Items with no part number specified are non proprietary and are not offered as available items PART NO 71133849 71133037 71102326 71133034 71133746 71133747 71133748 71133749 71134281 71121101 71102619 71133660 71133035 71133036 71127394 71127396 71133155 71127395 71115201 71118549 TABLE 5 1 TROOPER PARTS LIST DESCRIPTION Assembly Platter Trooper Keyboard amp Overlay Bubble Level Dia 16 5mm Upper Housing Trooper Screw 4 8 Load Cell Assembly 3kg With Frame Load Cell Assembly 6kg With Frame Load Cell Assembly 15kg With Frame Load Cell Assembly 30kg With Frame Assembly main PCB Trooper Screw M4x6 Screw M3x8 Washer Dia 3mm Nut DSO26AS Nut M3 GB6170 86 Harness PWR COM Trooper Bottom Housing Trooper Cover Battery Trooper Reed CD11 Reed Il CD11 Co
30. play as well as parameter storage to EEPROM U11 A TTL level signal is also provided to U1 202 for 5232 communications 2 3 4 MELSI U8 The MELSI U8 is a digital controller used in conjunction with the A D Converter It provides all digital functions required to run two independent A D channels The oscillator of the MELSI works with an external crystal Y2 which operates at a frequency of 11 0592MHz 2 3 5 Memory Storage The EEPROM U11 isthe user memory storage device for the indicator It contains 1024 bits of memory and stores the calibration data and the selected units which are enabled and disabled When the scale is turned off all previous settings are retained 2 3 6 LCD Display Information The display information for the LCD comes directly from microprocessor U7 and is decoded with it s internal circuits The LCD is backlit by panel BL1 and driver circuitry BL2 operated from BKLIT signal from microprocessor U7 2 3 7 Display ON OFF The unit contains an ON OFF button There is a power save mode in the software When this feature is enabled the scale will automatically turn off after 5 minutes after last keypad operation 2 38 Converter The A D converter takes the analog input voltage from the load cells and produces a digital output code which represents the analog input This is derived through U3 04 and U5 circuitry The SEN line is to compensate for temperature influence Two jumpers Jump1 and Jump 2 may short t
31. played readings are compared with the tolerances listed in Table 4 2 Tolerance values are expressed in counts A one count change is equal to the last digit shown on the scale display TABLE 4 2 TYPES OF PERFORMANCE TESTS PERFORMANCE TEST TOLERANCE COUNTS 9 Repeatability SD EE EE The following performance tests are used to evaluate the scale operation before and after repairs Each scale tested must meet the requirements specified in each test as well as the specifications listed in Tables 1 2 and 1 3 depending upon the model Before proceeding with the following tests all the procedures starting with paragraph 4 2 must have been accomplished on the scale first 4 2 7 1 Repeatabilty Test To conduct a Repeatability Test proceed as follows 1 With the scale calibrated place a mass on the Platform equal to the capacity of the scale Record the reading 2 Remove the mass from the Platform the scale should return to Og Record the reading 3 Repeat steps 1 and 2 ten more times Subtract the lowest from the highest reading to determine the difference Maximum allowable difference is as listed in Table 4 2 4 10 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 7 2 Off Center Load Test The Off Center Load Test is used to determine whether displayed weight values will be affected by moving the sample to different areas of the Platform See Figure 4 6 Place 1 2 ofthe scale capacity in the center of the Platform Press the ON ZER
32. ply pressing PRINT UNITS Data Out TXD Data In RXD ae 00000 roun ODAO Figure 4 7 RS232 Interface Pin Connections 1 2 3 4 5 6 7 8 9 4 13 CHAPTER 4 MAINTENANCE PROCEDURES 4 2 8 1 Connecting the RS232 Interface Cont RS232 Commands All communication is accomplished using standard ASCII format Only the characters shown in the RS232 Command Table 4 4 are acknowledged by the scale Invalid command response ES error indicates the scale has not recogonized the command Commands sent to the scale must be terminated with a line feed LF or carriage return line line feed CRLF Data output by the scale is always terminated with a carriage return line feed CRLF TABLE 4 4 5232 COMMANDS Command Character Description Printcurrent mode kg g Ib oz Same as pressing PRINT button E GE 2 Same as pressing TARE button Same as pressing ZERO button 5 Print Stable only Where x 0 Off and x 1 On Automatically send data when stable after motion xxxxS Send at interval Where 1 to 3600 seconds Send as fast as possible continuous print M Incrementto next enabled unit To turn auto printing interval printing or continuous printing off send P to reset normal printing mode 4 2 9 Print Test 1 Remove all weight from the platform 2 Press the ON ZERO OFF button once 0 0g should be displayed 3 Place a mass on the Platform 4 Press Print U
33. rea is clean and use care when handling components of the scale 3 2 DIAGNOSTIC GUIDE Table 3 1 is a diagnostic guide designed to help locate the problem area quickly and easily To use the table first locate the symptom that you are observing Follow the symptom column and review the probable cause column and remedy column The probable causes are listed with the most common cause first Ifthe first remedy does notfixthe problem proceed onto the nextremedy Before attempting to repair the scale read all chapters of this manual to familiarize yourself with the scale components and operation Do not attempt repairs unless you fully understand the operation of the scale 3 2 4 Diagnosis 1 Isolate and identify the symptom 2 Referto Table 3 1 Diagnostic guide and locate the symptom 3 Follow the suggested remedies in the order that they appear 4 Perform the indicated checks or see the appropriate section of the manual 5 Repair or replace the defective section of the scale NOTE If more than one symptom is observed it is necessary to approach one area at a time and also remember that the symptoms may be interrelated In the event that erratic or fluctuating weight readings are observed it is necessary to isolate the problem to either the mechanical area or the electronic area of the scale If a problem arises that is not covered in this manual contact Ohaus Corporation 19A Chapin Road P O Box 2033 Pine Brook 07058
34. s that the Scale reads correctly within specifications For best results calibrate at full capacity Calibration unit can be set to either kg or Ib NOTE When the Scale is used in Legal for trade applications the calibration menu is locked out and is not accessable This is to prevent unauthorized personnel from changing calibration IMPORTANT Before beginning calibration make sure masses are available If you begin calibration and realize calibration masses are not available exit the menu The Scale will retain previously stored calibration data Calibration should be performed as necessary to ensure accurate weighing You have a choice of either span or linearity calibration Span calibration checks zero and full span calibration points Linearity calibration checks zero mid span and full span points Before calibrating the scale first determine if a recalibration is really needed Place the available calibration masses onto the platform As each mass is added the scale display should show the correct weight to within 1 scale division If the scale is within the tolerance there is no need to recalibrate the scale If itis determined that the scale must be recalibrated do not continue until you are certain that you have suitable calibration masses If calibration masses are available you must select the correct calibration units bound masses or kilogram masses before calibrating the scale The desired unit can be chosen in the s
35. t be restored or the Scale must be recalibrated using the current settings CHAPTER 3 TROUBLESHOOTING 3 4 CHAPTER 4 MAINTENANCE PROCEDURES 4 1 PREVENTIVE MAINTENANCE Ohaus scales are precision instruments and should be carefully handled stored in a clean dry area which is dust free and cleaned periodically It is recommended that when a scale has had chemicals or liquids spilled on it the scale should be cleaned as soon as possible Use warm water on a damp cloth to clean all exterior surfaces Do not leave a mass on the scale when not in use When moving the scale from a storage area which is at a different temperature than the area where itis to be operated allow sufficient time for the scale s mechanism to temperature stabilize This time can vary quite a bit depending upon the temperature differences Allow one 1 hour for each 5 degrees Fahrenheit temperature change before using the scale Also after turning the scale ON allow one hour after temperature stabilization for the scale electronics to stabilize 4 1 1 Preventive Maintenance Checklist On a regular basis the scale should be inspected and checked as follows 1 Remove the Platform and inspect and clean the area beneath the Platform Remove any accumulated dirt or dust 2 Clean the outside of the scale using a damp cloth with water CAUTION DO NOT USE CHEMICAL CLEANERS OR SOLVENTS OF ANY TYPE SOME CLEANERS ARE ABRASIVE AND MAY AFFECT THE FINISH OF THE SCALE
36. tthe calibration unit is the same as the displayed unit listed TABLE 1 3 TROOPER GENERAL SPECIFICATIONS General Specifications Platform Size w x d in cm 135X9 34 X 23 Scale Dimensions w x d x h in cm 13 5 X 14 5 X 45 34 3 X 36 8 X 11 4 Shipping Dimensions w x d x h in cm 17X17X8 5 42 2X 422 X 21 6 Weight Ib kg 8 6 3 9 Resolution NTEP 1 3000 Resolution Maximum 6 000 7 500 depending on model Stabilization time 1 4seconds depending upon filter selection Keyboard 4 function membrane switches Weighing units Ib kg g oz Display Backlit LCD 25 4mm 1 Power AC Adapter or 6 alkaline C type batteries Typical Battery Life Up to 100 hours Span Calibration 1 3 to full capacity Linearity Calibration 3 point calibration Al models Auto zero tracking Off 0 5 1 or 3 divisions Construction Stainless steel weighing pan ABS plastic housing Protection IP 43 Operating Temperature 14 F to 104 F 10 C to 40 C Storage Temperature 40 F to 140 F 20 C to 60 C NOTE All Trooper models meet the requirements of Approval Agencies UL FCC CSA CE NTEP approval 1 4 CHAPTER 2 THEORY OPERATION 2 1 TROOPER THEORY OF OPERATION This chapter contains information on the basic theory of operation of the Loadcell and scale circuit descriptions of the printed circuit board An exploded view drawing is included in Chapter 5 which identifies all servicable components of the scale The descriptions in this manual refer
37. tton Short press prints data which is displayed on the Scale Long press changes unit of measure Longer press enters counting mode When in menus each press advances horizontally through the menus Finalizes a menu selection Tare button When pressed enters tare value into memory G N T Menu button Recalls Gross Net Tare Long press allows entry into menus When in menus advances through individual menu items LCD indicator when lit indicates weight in kilograms LCD indicator when lit indicates weight in grams LCD indicator when lit indicates weight in pounds LCD indicator when lit indicates weight in ounces Stability indicator when lit indicates stable weight 1 1 CHAPTER 1 INTRODUCTION 1 2 INTRODUCTION This service manual contains instructions for the repair and maintenance work to be performed by service engineers on the Trooper Scales It is assumed that the reader is familiar with the operation of the Scale and can refer to the relevant operating instructions when necessary This manual covers maintenance on the following Trooper Scales capacities 3kg 6kg 15kg and 30kg The contents of this manual is contained in five chapters Chapter 1 Introduction Contains information regarding service facilities tools and test equipment test masses and specifications Chapter 2 Theory of Operation Contains a basic information on circuit and loadcell operation Chapter 3 Troubleshooting Contains a
38. ver sealing Trooper Reed CD11 Foot Tiger Screw Sealing M4x8 Screw M4x8 CHAPTER 5 DRAWINGS AND PARTS LISTS QUANTITY CHAPTER 5 DRAWINGS AND PARTS LISTS Harness PWR COM GND 71133660 Load Cell 6 5kg 71132247 15kg 71134510 30kg 71134509 40kg 71134830 KBD Overlay Main Trooper 71134281 71133037 Figure 5 2 Trooper Scale Interconnection Diagram ao COMM PRINT UNITS KEYBOARD 3 G N T_ amp MENU OUTPUT y ON ZERO amp OFF TARE 5 1 2 Figure 5 3 Keypad Wiring Diagram 5 4 SERVICE MANUAL TROOPER SCALES P N 80250901
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