manualshive.com logo in svg

OHAUS CKW-55, Service Manual, Page: 24 / 68

Share
Download
OHAUS CKW-55 Service Manual Download Page 24

3-4

CHAPTER 3 INDICATOR TESTING

5. Using a DVM, measure the power supply voltage across pins 1 and 3 of J5, location A in Figure

3-3, it should be 12 volts dc, +0.24V dc.  This is the power source for the Main PC board and
is regulated.   If the voltage is low or is not present, refer to section 3.3 and test the Power
Supply Board.  If the Power Supply board is defective, refer to section 4.4 and replace the board
and continue with this procedure.  If the board is OK, continue with this procedure.

NOTE

: All voltage measurements are made with respect to case ground.

Figure 3-2. Interconnection Diagram.

3.2.1 Voltage Measurements (Cont.)

EP3 

Summary of Contents for CKW-55

Page 1: ...Ohaus Corporation 19A Chapin Road P O Box 2033 Pine Brook NJ 07058 973 377 9000 CKW 55 INDICATOR SERVICE MANUAL T...

Page 2: ......

Page 3: ...sumes no liability arising from the use or misuse of this material Reproductionofthismaterialisstrictlyprohibited Material in this manual is subject to change Copyright 2006 Ohaus Corporation all righ...

Page 4: ......

Page 5: ...3 3 2 2 Simulator Testing 3 6 3 3 Power Supply Testing 3 7 3 3 1 Voltage measurements 3 7 3 4 Battery Testing 3 8 3 4 1 General Information 3 8 3 4 2 Troubleshooting the Battery 3 9 3 5 Recharge Board...

Page 6: ...Housing 4 1 4 2 Replacing the Membrane Switch 4 1 4 3 Replacing the Main PC Board 4 2 4 4 Replacing the Power supply 4 2 4 5 Replacing the Optional Recharge Board 4 3 4 6 Replacing the Optional Relay...

Page 7: ...4 2 7 Relay Operation Failure Optional board 2 4 2 8 Indicator Display Incorrect or Unstable 2 5 2 9 Unable to Maintain Time and Date Functions 2 5 2 10 Error Code Table 2 6 3 1 Membrane Switch Contin...

Page 8: ...3 14 3 8 Relay Board Without Terminal Cover 3 14 3 9 RS422 485 Typical 4 wire Duplex Connection 3 18 3 10 RS422 485 Typical 2 Wire Half Duplex Connection 3 18 3 11 RS422 485 Location in Housing 3 19...

Page 9: ...pter 4 RepairProcedures ContainsdetailedrepairproceduresforallmajorassembliesoftheCKW 55 Indicator including the optional Relay Board RS422 485 Communication Board the Recharge Board and Battery Chapt...

Page 10: ...librationmassesrequiredisdependentonthecapacityandreadabilityofthebaseused Themasses required to test the CKW 55 Indicator when connected to an Ohaus CKW base must meet the requirements of ASTM Class...

Page 11: ...om the AC power line pull out the plug The Indicator contains sensitive electronic components that are sensitive to electrostatic discharge We recommend that you wear a grounding wrist strap when doin...

Page 12: ...1 4 CHAPTER 1 INTRODUCTION...

Page 13: ...1 and observe and record power on information codes and software revision Record all menu settings if possible as received See section 3 9 4 On indicators equipped with an optional battery allow the...

Page 14: ...repair performOperationalTestsinsection3 9 2 1 INDICATOR WILL NOT TURN ON WITH AC POWER Cont SYMPTOM Indicator will not turn on using battery power PROBABLE CAUSE Battery discharged or defec tive Wir...

Page 15: ...Replaceifnecessary See Repair Procedure 4 2 If membrane switches are OK refer to section 3 2 and test the Main PC Board If defective replace the Main PC Board SeeRepairProcedures4 3 Afterrepair perfo...

Page 16: ...on 3 9 TABLE 2 6 RS422 485 COMMUNICATIONS FAILURE OPTIONAL BOARD SYMPTOM Cannot communicate using RS232 PROBABLE CAUSE Menusettingsimproperlyset Main PC board defective REMEDY Refer to the Instruction...

Page 17: ...nd date PROBABLE CAUSE Real Time Clock RTC bat tery depleted Main PC Board defective TABLE 2 9 UNABLE TO MAINTAIN TIME AND DATE FUNCTIONS REMEDY Replace the Real Time Clock battery Refer to section 4...

Page 18: ...te the Indicator Clear platform of excess mass or recalibrate to establish a new zero point Go through all menus and re establish all settings or go to each menu and reset to default settings Check op...

Page 19: ...al low battery to charge Refer to section 3 4 and test the battery Replace if necessary See Repair Proce dure 4 8 Clear platform of excess masses or recalibrate to establish a new zero point Refer to...

Page 20: ...2 8 CHAPTER 2 DIAGNOSIS...

Page 21: ...ld be replaced NOTE Depending upon pressure placed on the individual switch the resistance reading can vary anywhere from approximately 15 to 70 Ohms This is normal Check each switch on the panel The...

Page 22: ...3 1 MEMBRANE SWITCH CONTINUITY TEST FUNCTION SWITCH MEASURE ACROSS PINS LIBRARY 2 11 NEXT 2 10 TARGET 3 10 ON ZERO 8 9 PRINT 4 11 G N T 4 10 TARE 3 11 1 5 10 2 5 11 3 5 12 4 6 10 5 6 11 6 6 12 7 7 10...

Page 23: ...s Transistor Q1 and provides turn on of 12 V dc power to rest of circuit B IC U13 regulator provides 5 V dc to the board C IC U14 regulator provides the 5 V excitation for the external Load Cell D IC...

Page 24: ...and is regulated If the voltage is low or is not present refer to section 3 3 and test the Power Supply Board If the Power Supply board is defective refer to section 4 4 and replace the board and con...

Page 25: ...cell If this voltage is above or below these limits the Main PC Board should be replaced Refer to section 4 3 and replace the Main PC Board 9 Measure the voltage at IC U22 pin 2 location E it should...

Page 26: ...sing refer to procedure 4 1 3 Disconnect the Load Cell cable from connector J2 on the Main PC Board Refer to Figure 3 3 for connector location 4 Connect the Simulator to connector J2 See Figure 3 2 fo...

Page 27: ...se Check the fuse with an Ohmmeter If defective replace with a new fuse of the same type Reinstall protective fuse cover and reconnect ac power and measure voltage at connector CN2 If voltage is not p...

Page 28: ...ssembly Battery Monitor Chip The battery assembly contains a monitor chip that monitors voltage and temperature The chip also contains a small amount of non volatile memory The number of charge cycles...

Page 29: ...ttery operates the Indicator for less than 5 hours it should be replaced See section 4 8 for battery replacement procedures Note The power save function should be turned off to allow testing battery l...

Page 30: ...he maintenance charge starts A red LED indicates the detection of a battery system failure If the battery is new and has never been charged a one time extended time trickle charge is started this one...

Page 31: ...oard is working To confirm this momentarily press the C button at 1 or 2 minute intervals and note the battery voltage on the indicator display It should increase slightly with each button press As an...

Page 32: ...n replaced allow the battery to charge several hours WARNING HAZARDOUS VOLTAGES ARE PRESENT WITH THE INDICATOR HOUSING OPENED AND AC POWER IS APPLIED USE CARE WHEN MAKING ALL MEASUREMENTS 3 5 3 Voltag...

Page 33: ...s are replaceable The fuses one for each solid state relay output are replaceable 3 6 2 Relay Testing There are several reasons why the relays can fail they are listed as follows A Improper menu setti...

Page 34: ...3 14 CHAPTER 3 INDICATOR TESTING Figure 3 7 Relay Board with Terminal Cover Figure 3 8 Relay Board without Terminal Cover 3 6 2 Relay Testing Cont...

Page 35: ...er to the indicator Refer to the instruction manual and set the Indicator up to provide a test of each relay 3 For dc relay types use an Ohmmeter providing a minimum of 5 Volts DC and check each relay...

Page 36: ...PC board voltage checks should be normal in accordance with section 3 2 NOTE A possible failure could have occurred on the Main PC board RS232 components and still have normal operating voltages pres...

Page 37: ...ent Input Modes not used in range Mode xU Set weighing unit Where x 1 to 6 1 g 2 kg 3 lb 4 oz 5 lb ox 6 if x blank then increment to next available mode The unit can not be selected if it is not enabl...

Page 38: ...e the jumper arrangement shown in Figure 3 10 and 3 11 RS422 485 Typical 4 Wire and Typical 2 Wire Connections Note W1 must be shorted to allow 2 wire communications W2 must be shorted on the last sca...

Page 39: ...r and enter the COM menu and set the Baud Rate Parity Data Length Stop Bit Handshake Type to RS485 and address number then exit the menu 6 On the computer set the correct COM port and all settings on...

Page 40: ...elay operation Stop Tare Start Stop T S S The first external input signal initiates a Tare function The second external input signal enables the output relay operation Start The third external input s...

Page 41: ...and annunciators will light simul taneously at the previously selected setup brightness for 1 second Simultaneously the Beeper will sound at the previously selected setup volume for 1 2 sec Power On...

Page 42: ...ion may be different depending on the last set up of the Indicator When Tare is not active Gross weight is displayed by default If Tare is active NET weight is displayed 3 9 2 Turning Off the Indicato...

Page 43: ...WARNING HAZARDOUS VOLTAGES ARE PRESENT WITH THE INDICATOR HOUSING OPENED AND AC POWER IS APPLIED 1 Disconnect power from the Indicator Remove the line cord plug from the power source 2 Open the Front...

Page 44: ...l OFF Display Signal OFF Graph Incr Auto Graph Display Bar Print Menu Print Stable ON Auto Print OFF Print Content On Date Time GMP User ID GMP Proj ID GMP Scale ID GMP Name ID Format Column Feed OFF...

Page 45: ...ht 3 0 kg 6 61 lb Operating Temperature Range 10 C to 40 C 14 F to 104 F Power 100 240 VAC 50 60 Hz Universal Power Supply Hardwire Cord Optional Internal Rechargeable NiMH Battery 10 hour operation i...

Page 46: ...ect the wires to Terminal Strip J2 according to the proper signal names See Figure 3 12 Tighten all terminal screws securely 5 When connecting a 2 mv v load cell Jumper W1 is to be left in place short...

Page 47: ...ress the TARE button anytime during the process The Indicator will retain previously stored calibration data 3 12 1 SpanCalibration Span Calibration uses two points to adjust the scale One point is ca...

Page 48: ...ation was successful the calibration weight is displayed and the scale exits automatically to the active weighing mode Remove the weight and begin weighing operations 3 12 2 LinearityCalibration Linea...

Page 49: ...ndicator When any selection within the Read GMP menu is enabled calibration test results are automatically printed NOTE The Calibration Test function is available even when the CAL menu is locked out...

Page 50: ...the Geo factor is set to correspond to the geographical location where the calibration is being performed Following calibration the Geo factor is changed to match the location where the scale is to b...

Page 51: ...11 11 41 12 42 19 16 16 15 15 14 14 13 13 12 12 11 42 19 43 26 17 16 16 15 15 14 14 13 13 12 12 43 26 44 32 17 17 16 16 15 15 14 14 13 13 12 44 32 45 38 18 17 17 16 16 15 15 14 14 13 13 45 38 46 45 1...

Page 52: ...s of troubleshooting and calibration 1 Remove power from the Indicator Refer to section 4 1 and open the Front Housing 2 See Figure 3 14 Printed Circuit Board Connections and remove the switch cover R...

Page 53: ...and perform a span calibration 2 Follow the Indicator prompts When the Indicator indicates a given mass should be placed on the base set the Simulator to an equivalent value to simulate the output for...

Page 54: ...DINGS FOR CKW BASES NOMINAL OUTPUT IN MILLIVOLTS AT 5 VOLTS EXCITATION CAPACITY ZERO 50 100 3 kg 4 3 2 0 Zero 2 3 Zero 4 7 6 kg 1 6 2 0 Zero 2 8 Zero 5 6 15 kg 1 7 2 0 Zero 2 4 Zero 4 8 30kg 1 3 2 0 Z...

Page 55: ...fer to section 4 1 and open the Front Housing 3 With the Housing opened disconnect the connector from J1 on the Main PC board This is the cable from the Membrane Switch 4 Facing the front panel of the...

Page 56: ...place and remove the Main PC board One screw contains a grounding clip 7 Replace the Main PC board and install the four screws previously removed Make sure the grounding clip is in place under one of...

Page 57: ...r screws holding the Recharge board in place and remove the Recharge board 5 Replace the Recharge board and install the four screws previously removed 6 Reconnect connectors J1 and J2 to the Recharge...

Page 58: ...ON BOARD The RS422 485 Communication board is supplied as an optional kit NOTE Read this procedure through first before proceeding 1 Remove AC power from the Indicator 2 Refer to section 4 1 and open...

Page 59: ...ure 5 1 6 While holding the battery in place mount the center bracket using the supplied screws The mounting screws must remain loose at this step NOTE The center bracket is the part without the extra...

Page 60: ...older 5 To install a new battery into the holder hold the battery with the mark facing up Slide the battery under the Contact Clip until the Retaining Clip springs up and locks the battery in place CA...

Page 61: ...is made The Indicator MUST meets the parameters of all applicable specifications in this manual If further technical information is needed in the United States call toll free 1 800 526 0659 between 8...

Page 62: ...5 2 CHAPTER 5 PARTS LISTS 5 1 CKW 55 INDICATOR EXPLODED VIEW Figure 5 1 Exploded View of CKW 55 Indicator...

Page 63: ...g P7 CKW 7mm ID 17 71209067 I O Fitting P9 CKW 9mm ID 19 71209084 Cable Power Supply CKW 20 71209078 Fuse Power Supply Kit of 2 CKW 21 71209061 LFT Cover with hardware CKW 24 71154804 Gasket CKW 80251...

Page 64: ...olumn TABLE 5 2 CKW 55 COLUMN PARTS LIST ITEM NO PART NO DESCRIPTION 1 71167972 Column Mount Accessory SS CKW Tube 230mm 1 80251059 Column Mount Accessory SS CKW Tube 6800 mm 2 71128010 Cable Clamp CK...

Page 65: ...SV Enters the Monitor Mode esc RS Reset the scale similar to power off and on and exits the Monitor Mode esc EPX Indicator is set to 10 times expanded display mode X 1 ON X 0 OFF esc DF Resets all sca...

Page 66: ...C 099 c 036 068 D 100 d 037 069 E 101 e 038 070 F 102 f 039 071 G 103 g 040 072 H 104 h 041 073 I 105 i 042 074 J 106 j 043 075 K 107 k 044 076 L 108 l 045 077 M 109 m 046 078 N 110 n 047 079 O 111 o...

Page 67: ......

Page 68: ...19A Chapin Road P O Box 2033 Pine Brook NJ 07058 USA Tel 973 377 9000 Fax 973 944 7177 www ohaus com With offices worldwide www ohaus com P N 80251063 Ohaus Corporation 2006 all rights reserved Printe...

Reviews:

No comments