background image

 

Ohaus Corporation  www.ohaus.com 

11 

Defender

™ Series Bases Service Manual 

 

CHAPTER 2  TROUBLESHOOTING 

 

Aside from installing components and leveling adjustments, the Defender Series Base does not require any 
other adjustments as shipped from the factory. 

 

Operational difficulties that may be encountered can often be traced to simple causes such as: 

 

Loose or incorrect wiring connections 

 

Failure to remove the shipping spacers 

 

Obstructions to the base frame 

 

Unstable environments 

 

Incorrect calibration or setup of the indicator 

 

2.1 

Troubleshooting 

This section of the manual provides guidelines for evaluating the condition and performance of a Base unit, 
and a standard troubleshooting methodology to follow. 

2.1.1  Checking Load Cells for Trouble 

 

Visual Check:

  Examine the Load Cell for signs of bending, twisting or corrosion. 

–  Clean the unit before evaluating any mechanical problems.  In some cases, debris may have 

accumulated inside the Base Housing.  Make sure there is no buildup of any foreign material. 

–  Examine the Base Housing for dents, bent Platform or signs of physical abuse that could 

cause the Base to malfunction.  Make sure that the proper Platform is supplied with the Base. 
Replace all damaged parts.  See Chapter 5 for parts list. 

– 

Remove the Platform from the Base.  Check that the Overload Stops are not touching the Top 
Plate. This would restrict movement, causing improper operation of the Base.  If the Overload 
Stops are improperly set, adjust them.  (See Section 3.3.)

 

–  Check the metal surfaces of the Platform.  All surfaces should be parallel.   

If the platform is deformed, it should be replaced. 

–  Check the cables leading to the Load Cell for cuts, abrasions or other signs of excessive wear 

and tear. 

–  Check for a bent or twisted Load Cell:

  

Place the top surface and then each of the sides of the 

Load Cell on a flat surface, to see if it rests flat and even. A gap indicates a bent or twisted 
Load Cell. 

–  Examine the Load Cell for corrosion due to high humidity or exposure to chemicals. 

–  A Load Cell that is even slightly bent or corroded should be replaced. 

Perform a Resistance Test

, to determine if the Load Cell is severely damaged or a short 

circuit to the frame has occurred.  (See Chapter 4 for details.) 

Perform an Output Voltage Test

:

  

Measure the no load, 50% load and full load output.

 

The reading should meet the Load Cell specifications.  (See Chapter 4.) 

– 

The Load Cell output should be very close to linear over its capacity range.  

 

 

 

Содержание Defender 6000 Series

Страница 1: ...ustin Ft Worth NicolScales com 800 225 8181 Contact Us Nicol Scales Measurement is an ISO Accredited Calibration Company that has provided calibration repair and sales of all types of weighing and mea...

Страница 2: ...DefenderTM 6000 Series Base Service Manual...

Страница 3: ...hecking Load Cells for Trouble 11 CHAPTER 3 MAINTENANCE AND REPAIR PROCEDURES 12 3 1 Preventive Maintenance 12 3 1 1 Preventive Maintenance Checklist 12 3 2 Replacing the Load Cell 12 3 3 Overload Sto...

Страница 4: ...uides for operational and performance tests and adjustments Chapter 5 Parts Identification Contains exploded views of Defender series Bases and parts identifying all serviceable components with parts...

Страница 5: ...intended for indoor use and should only be operated in dry locations Operate the equipment only under ambient conditions specified in the user instructions Do not operate the equipment in hazardous o...

Страница 6: ...irements of ASTM Class or OIML Mass values 3kg to 600kg depending on the Base model The full scale rated capacity of the Base should be used for Span calibration 1 7 Service Strategy The Load Cells us...

Страница 7: ...Capacity 3 kg 6 kg 15 kg 30 kg 60 kg 150 kg Approved Resolution OIML 3000e Safe Overload Capacity 150 of capacity Pan Dimensions 254 x 254 mm 10 x 10 in 305 x 305 mm 12 x 12 in 400 x 500 mm 15 7 x 19...

Страница 8: ...400 x 500 mm 15 7 x 19 6 in Base Construction Stainless Steel platform with stainless steel frame and rubber leveling feet Repeatability std deviation 2d Linearity 2d Load Cell Capacity 10 kg 20 kg 50...

Страница 9: ...Pan Dimensions 254x 254 mm 305 x 305 mm 400 x 500 mm 600 x 800 mm Base Construction Stainless Steel platform with stainless steel frame and rubber leveling feet Load Cell Capacity 10 kg 10 kg 20 kg 5...

Страница 10: ...luences such as moisture physical damage or electrical interference The strain gauges are wired into a Wheatstone Bridge Circuit See Figure 1 1 Figure 1 1 Downward force on the Platform bends the beam...

Страница 11: ...eight is loaded to the Load Cell For example a 500kg Load Cell with 2mV V output and 5V excitation would have a change of 0 02mV per kg change in the load that is 10mV 500 0 02mV per kg At a load of 2...

Страница 12: ...com 10 Defender Series Bases Service Manual Type2 For models i D150K1L i D300K1VZH i D600K1VZH bases FUNCTION WIRE COLOR Excitation Green Excitation Black Signal White Signal Red Sense Light Yellow Se...

Страница 13: ...unction Make sure that the proper Platform is supplied with the Base Replace all damaged parts See Chapter 5 for parts list Remove the Platform from the Base Check that the Overload Stops are not touc...

Страница 14: ...efore using the base 3 1 1 Preventive Maintenance Checklist The scale should be inspected and checked regularly as follows 1 Clean the base 2 Remove the Platform to inspect and clean the area beneath...

Страница 15: ...m Frame and the Load Cell Spacer aside 4 Remove the Top Load Cell Mounting Bolts washers and spacer The Load Cell assembly can now be removed from the Top Frame 5 Remove the Mounting Block Bolts from...

Страница 16: ...t and re check the Gap 4 Re adjust if necessary 5 Cover the Platform and check for full capacity See Table 3 1 for Gap settings TABLE 3 1 OVERLOAD GAP SETTINGS FOR DEFENDER SERIES BASES Base Model Bas...

Страница 17: ...ARTTENTION Make sure the test area is free from drafts and that the base rests on a level and vibration free surface 4 2 Load Cell Resistance Checks Use an ohm meter to measure across each pair of wi...

Страница 18: ...nnect the excitation signal shield and sensing wires if provided to the Indicator Calibrate the Indicator to read the load in the units required for example kilograms or grams Consult the Indicator in...

Страница 19: ...NG 3 Using an mV meter measure and record the signal voltage 4 Obtain the mV V output figure from the Load Cell data supplied with the Load Cell and compare the signal changes seen with the theoretica...

Страница 20: ...ssed the Load Cell must be adjusted or replaced Prior to starting this test the Base must be connected to a properly functioning Indicator with capacity and readability values set according to the spe...

Страница 21: ...Move the weight to point D and record the reading 7 If the reading at point A is negative file at points 1 and 4 AT AN ANGLE 8 If the reading at point B is negative file at points 1 and 2 STRAIGHT ACR...

Страница 22: ...ll cases where a part is replaced the base must be thoroughly checked after the replacement is made The base MUST meet the parameters of all applicable specifications in this manual If further technic...

Страница 23: ...R S Base Figure 5 1 Defender 6000 series Base R S Base Drawing Item Description Comments 1 Plate S Base i DT61 Plate R Base i DT61 2 Loadcell 1 PW15AHC3 10KG 1 i D3K1S i D5K1S i D6K1S i D3K1SZH i D6K1...

Страница 24: ...L Base Drawing Item Description Comments 1 Pan 400x500 SUS316 i DT61 2 Loadcell 1 PW15AHC3 100KG 1 i D50K1L i D60K1L i D60K1LZH Loadcell SSH 200kg 2 5m i D150K1L Loadcell SSH 300kg 2 5m i D150K1LZH 3...

Страница 25: ...ll SSH 500kg 2 5m i D300K1VZH Loadcell SSH 1t 2 5m i D600K1VZH 3 Level Kit D52 SST Base 4 Hardware Kit V Base i DT61 5 Foot 4 S R L base i DT61 6 Rubber Support SST Base i DT61 NS Box V D52 NS Box Com...

Страница 26: ...ugh typically there may be a small offset voltage at zero load Over the full rated capacity of the load cell the mV output will change The amount by which it changes depends upon the resistance change...

Страница 27: ...S Corporation 7 Campus Drive Suite 310 Parsippany NJ 07054 USA Tel 1 973 377 9000 Fax 1 973 944 7177 With offices worldwide www ohaus com 30655626 P N 30655626A 2021 OHAUS Corporation all rights reser...

Отзывы: