ICA4 Manual - Straightpoint
Contents
1. amp with the power off c Check the Excitation voltage is at 8V dc d Check the calibration e Check the Zero offset is correct for the sensor this too is a common reason for low outputs 3 High Output This is when an output is present but higher in span or zero than expected High output is not normally a problem It is most likely to be incorrect connections and as such the output would be high and fixed a Check the sensor is connected typically reading 350 Ohm across output amp with the power off b Check the Excitation voltage is at 8V dc c Check the Zero offset d Check the calibration 4 Unstable Output This is when the output is unstable or varies The cause could be a poor installation or b a noisy environment Poor Installation This is when an output is present but higher or lower in span or zero than expected a Check the installation for problems and repair where necessary b Poor termination c High resistance on cable leads d Low insulation impedance e Proximity to High Voltage Equipment Transformers Contactors Motors etc Noisy Environment a Check if the source can be found and remove noise b Check the cable shielding and ensure it is correctly installed and terminated 5 Calibration This section assumes that the unit is providing an output that is not stuck at top or bottom of the scale See paragraphs 1 3 if this is the case Ensure you are connected to the correct2. via the external supply through the load towards ground OV This mode has the advantage that the negative output connection is common to the load cell Excitation terminal In Sink mode the positive end of the load is connected to the positive of the power supply a separate external power supply may be used if desired and the negative end of the load is connected to the ICA4 output terminal The current through the load is sunk by the ICA4 towards the negative of the supply OV When in this mode neither connection to the output load is electrically common to the load cell Note If the ICA4 is required to operate in source mode common negative as per the Figure 2 2 then the above 4 wire cabling should be adhered to in order to provide the ICA4 with maximum protection If however a 3 wire cabling installation is required or unavoidable the on board protection circuit will limit the fault current in the load to approximately 55mA in the event of the negative supply connection to the ICA4 becoming open circuit 2CA4 User Manual Issue 1 7 3 Calibration Figure 4 1 Connection Details for Calibration Source Mode Ammeter Display Sink Mode Ammeter Display 1 Turn both potentiometers fully clockwise Now turn the S potentiometer seven turns anti clockwise mid way 2 Apply the low calibration conditions weight force or mV V Set the output to approximately 4mA using the Z pote
3. SP straightpoint world leaders in load monitoring technology ICA4 analogue output option Setup and user guide 1 Power Connections The power supply for the ICA4 is 24V dc within the limits of 13V to 28 V Figure 2 2 Connection Details for Current Source Mode ICA4 Source Mode Connection For optimum EMC performance connect to load cell body Load Cell Body Note Output is connected internally to the Supply terminal Current flow Supply L tp OUtput ICA4 Output Stage ICA4 Supply or Common Figure 2 3 Connection Details for Current Sink Mode ICA4 Sink Mode Connection Supply 5 For optimum EMC performance connect to load cell body Output Load Cell Body Note Output is connected internally to the Supply terminal Current flow Supply ey eo Supply or Common end of load can be connected to separate 5 30 V supply if required ICA4 User Manual Issue 1 7 2 Output Connections The ICA4 analogue output is 4 to 20 mA other modules in the ICA range offer DC voltage outputs The DC current output supports both sink and source modes of operation A link provides the means of selecting the desired mode See Figures 2 2 and 2 3 for details In Source mode the positive end of the load is connected to the ICA4 output terminal and the current is sourced by the ICA4 output
4. de Configuration sink or source mode Connections Solder pads 4 strain gauge 3 or 4 for power amp signal Environmental Approvals Emissions BS EN 55011 1998 Immunity BS EN 61000 4 2 1995 IEC 6100 4 2 1995 BS EN 61000 4 3 2002 BS EN 61000 4 4 2004 BS EN 61000 4 11 2004 Output shall not exceed the sum of uncertainties when subjected to an electric field of 10V m over the frequency range 80 to 600MHz Safety Low voltage Directive 73 23 EEC as amended by 93 68 EEC BS EN 61010 1 2001 IEC 61010 1 2001 ICA4 User Manual Issue 1 7 Units V dc Ohms mvV V t FS FS Ohms Hz C C FS 2G RH
5. ntiometer Note the exact reading 3 Apply the known high calibration conditions ideally between 75 and full scale and adjust the S potentiometer to give the required increase in output current for the known input e g 16mA increase for 4 20mA final calibration 4 Apply the low calibration conditions again and note the new value Apply the high conditions and re adjust the S potentiometer for the required change 5 Repeat steps 2 and 3 until the span is correct 6 Apply the low calibration conditions and adjust the Z potentiometer for the required output reading ICA4 User Manual Issue 1 7 4 Troubleshooting 1 No Output a Check power supply is present and the correct polarity b Check the output connections are correct with no open circuit connections c Check terminations ensure there are no dry joints d Check the sensor is connected typically reading 350 Ohm across output amp with the power off e Check the Excitation voltage is correct f Check the load is connected and is not open or short circuited g Check Span and Gain calibration 2 Low Output This is when an output is present but not of sufficient magnitude to meet the required value Remember to allow for Tare Weight and ensure it is measured and allowed for in the output from the ICA a Check power supply is within specified limits i e is not low b Check the sensor is connected typically reading 350 Ohm across output
6. sensor and not to another adjacent unit Ensure you have the correct calibration data from the sensor manufacturer This must include a certified table with offset zero and linearity Ensure you have the calibration set up correctly installed i e mV source and output as required Ensure the temperature and other environmental parameters are within specification and where necessary taken into account when calibrating should such parameters have an effect on the calibration 6 Fine Span Gain and Zero Offset Adjustment Problems If the adjustment cannot reach the maximum output desired then check the tare is not too high If the potentiometer does not alter the output the unit must be repaired remove from service It is always wise to check a known good ICA against the problem Installation before rejecting the suspect ICA 4CA4 User Manual Issue 1 7 5 Specifications for ICA4 Load Cell Amplifiers Table 8 1 Output from the ICA4 4 20mA Parameter Minimum Typical Maximum Power supply reverse protected 13 24 28 Bridge excitation 8 Bridge resistance 350 Bridge sensitivity 0 5 2 5 30 Gain adjustment Pot fine adj 8 Zero adjustment Pot fine adj 2 Output load 3 1000 Bandwidth 0 2000 Zero temperature stability 0 002 Span temperature stability 0 005 Linearity 0 02 Operating temperature range 40 85 Humidity 95 FS Full scale t set by calibration resistor 24V minimum supply sink mo
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