Rice Lake SCT-3300 User manual

SCT-3300
Signal Conditioning Transmitter
Installation Manual
PN 190937 Rev AMarch 11, 2020

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© Rice Lake Weighing Systems. All rights reserved.
Rice Lake Weighing Systems® is a registered trademark of
Rice Lake Weighing Systems.
All other brand or product names within this publication are trademarks or
registered trademarks of their respective companies.
All information contained within this publication is, to the best of our knowledge, complete and
accurate at the time of publication. Rice Lake Weighing Systems reserves the right to make
changes to the technology, features, specifications and design of the equipment without notice.
The most current version of this publication, software, firmware and all other product
updates can be found on our website:
www.ricelake.com

Contents
© Rice Lake Weighing Systems ● All Rights Reserved i
Contents
Technical training seminars are available through Rice Lake Weighing Systems.
Course descriptions and dates can be viewed at www.ricelake.com/training
or obtained by calling 715-234-9171 and asking for the training department.
1.0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.0 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.1 Load Cell Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.2 Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.3 Weight Oscillations (Vibration) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.4 Installation Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.5 Mechanical Installation Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.6 Analog Output Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.0 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 Calibration Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1.1 Zero Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1.2 Span Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 Calibration Through Simulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.0 Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.0 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

SCT-3300
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Rice Lake continually offers web-based video training on a growing selection
of product-related topics at no cost. Visit www.ricelake.com/webinars

Introduction
© Rice Lake Weighing Systems ● All Rights Reserved 1
1.0 Introduction
This manual is intended for use by service technicians responsible for installing and servicing SCT-3300 Signal Conditioning
Transmitters/Indicators.
This instrument must not be opened by the user. Any attempt to repair or alter the unit can expose the user to
the danger of electric shock and will void the warranty. If a problem with the unit or system is experienced,
please notify the manufacturer or the dealer.
1.1 Safety
Safety Signal Definitions:
Indicates an imminently hazardous situation that, if not avoided, will result in death or serious injury. Includes
hazards that are exposed when guards are removed.
Indicates a potentially hazardous situation that, if not avoided, could result in serious injury or death. Includes
hazards that are exposed when guards are removed.
Indicates a potentially hazardous situation that, if not avoided, could result in minor or moderate injury.
Indicates information about procedures that, if not observed, could result in damage to equipment or corruption
to and loss of data.
General Safety
Do not operate or work on this equipment unless this manual has been read and all instructions are understood.
Failure to follow the instructions or heed the warnings could result in injury or death. Contact any Rice Lake
Weighing Systems dealer for replacement manuals.
Failure to heed could result in serious injury or death.
Electric shock hazard!
Do not install in areas subject to explosion hazard.
There are no user serviceable parts. Refer to qualified service personnel for service.
Always disconnect from main power before performing any work on the device.
Do not allow minors (children) or inexperienced persons to operate this unit.
Do not operate without all shields and guards in place.
Do not use for purposes other then weighing applications.
Do not place fingers into slots or possible pinch points.
Do not use this product if any of the components are cracked.
Do not make alterations or modifications to the unit.
Do not remove or obscure warning labels.
Do not use near water.
Failure to follow could result in damage to equipment or corruption to and loss of data.
Keep away from heat sources and direct sunlight.
Protect the instrument from environmental factors: rain, snow, dust, etc.
Clean the instrument with a damp cloth, do not use anything but water
Always mount the instrument and platform in a vibration free setting.
All instrument connections must be made with respect to local zone and environment standards.
IMPORTANT
DANGER
WARNING
CAUTION
IMPORTANT
WARNING
IMPORTANT

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2.0 Installation
2.1 Load Cell Connections
Connect up to four load cells. The load cells are summed and provide an analog output signal. Adjustments for zero and span
can be made. There is an adjustment to increase stability to reduce the effect of environmental vibration.
The connections are for four-wire load cells, if using six-wire load cells connect the sense lines to the excitation. Power the unit
with 20–28 VDC. Analog outputs for 0–10 VDC, 0–20 mA or 4–20 mA are provided.
Figure 2-1. Connections
2.2 Start Up
Power on the indicator and wait 10 minutes for all components to reach a steady temperature. Ensure the scale is empty and
free from mechanical constraints.
Using a voltmeter make sure the output is positive and increases when weight is applied to the scale. If the output is negative
check the load cell connection and installation (the + and - signal may need to be reversed, whether the load cell is used in
tension or compression).
2.3 Weight Oscillations (Vibration)
If the displayed weight is not steady it is possible to increase stability by using the analog filter. Turn the potentiometer (P3)
clockwise to reduce the oscillations. To deactivate the filter remove the J2 jumper.
J2
Filter
22
E2
J1
23 2125 2426
1234567891011121314151617181920
SHIELD
+ SIGNAL
– SIGNAL
+ EXCITATION
– EXCITATION
SHIELD
+ SIGNAL
– SIGNAL
+ EXCITATION
– EXCITATION
SHIELD
+ SIGNAL
– SIGNAL
+ EXCITATION
– EXCITATION
SHIELD
+ SIGNAL
– SIGNAL
+ EXCITATION
– EXCITATION
+ mA
+ Volt
– COMMON ANALOG OUT
– SUPPLY 20-28 Vcc
+ SUPPLY 20-28 Vcc
P3
P1
P4

Installation
© Rice Lake Weighing Systems ● All Rights Reserved 3
2.4 Installation Considerations
• Use proper grounding by connecting the upper supporting plate to the lower supporting plate with copper wire, then
connect all the upper plates to the grounding system.
• For optimal functioning of the system, it is necessary to connect the transmitter, load cells, junction box and weighing
structure to a single point ground. Ground the transmitter terminal 26 (SHD) to the earth ground of the system.
• Use conduit to protect the load cell cables.
• Use a waterproof junction box to extend load cell cables or to sum the load cells.
• Load cell cables must have their own conduit and be run as far as possible from any power cables.
• Load cell cables must be shielded separately from high voltage lines to reduce electrical interference when passing
through troughs containing other cables.
• Use RC filters (Quench Arcs) on relays and control switches.
• The board installer is responsible for securing the electrical safety of the instruments (fuses, door-locking switch, etc.).
Avoid welding near load cells.
2.5 Mechanical Installation Check
1. With a voltmeter, measure the load cells excitation supply on the terminals 1 and 2 to read the actual 10 VDC
excitation value.
2. When the scale is empty measure the signal in mV on the terminals 3 and 4.
3. Put a calibration weight on the scale and measure the signal in mV again.
Make sure the signal increase corresponds to the result of the following equation:
mV Total/ FS Capacity = mV Change/ Cal Weight
•mV Total is excitation voltage x mV/V rating of load cells
•FS Capacity is load cell capacity x number of load cells
•mV Change is the millivolt change when the weight is applied
•Cal Weight is the amount of test weight
Example – Assume there are four 2,500 lb load cells for an FS Capacity of 10,000 lb
With a calibration weight of 1,000 lb, the signal increases to 2.0 mV
4. If the value in mV is correct and the output signal is wrong move on to Calibration (Section 3.0 on page 5).
5. If the value in mV is lower than the calculated value move on to the Load Cell Verification.
6. If the value in mV is greater than the calculated value move on to the Load Cell Verification.
If problems exist after completing the installation check, please call Rice Lake Weighing Systems for support.
mV Total =mV Change
FS Capacity Cal Weight
20 mV =XX = 20,000 X = 2.0 mV
10,000 lb 1,000 lb 10,000
IMPORTANT
Note

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2.6 Analog Output Modification
Figure 2-2. Analog Output Modification
• Remove the J1 jumper to obtain an analog output of 0–10 VDC (output on terminals 22–23)
• Remove the J1 jumper to obtain an analog output of 0–20 mA (output on terminals 21–23)
• Close the J1 jumper to obtain an analog output of 4–20 mA (output on terminals 21–23)
• If dead load exceeds 17 mV put a resistance of 10K (1/8 of Watt) instead of R33 (normally is 22 k)
• If signal exceeds 35 mV, add a 49.9K resistance (1% precision and temperature precision of 15 ppm) in parallel to R11
R33
R11
P3
P1
P4
Coarse Span
Coarse Zero
Fine Zero
Fine Span
J1 Jumper
J2 Jumper

Calibration
© Rice Lake Weighing Systems ● All Rights Reserved 5
3.0 Calibration
3.1 Calibration Check
The instrument supplied has already been calibrated. This section provides information to check and adjust the zero and span
calibrations. Always adjust the zero calibration first and then use a test weight equal to at least 50% of the max load capacity on
the scale to check and adjust the span calibration. If the span output is less than expected, verify the error is not caused by a
mechanical influence such as binding, side load, or angular load (see the Mechanical Installation Check, Section 2.5 on page 3 ).
Adjust the zero calibration (Section 3.1.1) before adjusting the span calibration (Section 3.1.2 on page 6).
3.1.1 Zero Calibration
Make sure the scale is empty, verify the output is 0 VDC, 0 mA or 4 mA and adjust as needed. See Table 3-1.
• Make sure the scale is empty
• Use the Fine Zero potentiometer for small variations or the Coarse Zero DIP switches to approach zero
Set DIP Switches of Coarse Zero (Figure 2-2 on page 4):
0 = OFF 1 = ON
Position of DIP Switches
(1234)
Input mV to Set to Zero
mV range with potentiometer
set to counterclockwise
mV range with potentiometer
set to clockwise
0000 -2.4 -0.4
1000 -0.2 2.6
0100 1.7 4.5
1100 3.4 6.2
0010 4.9 7.7
1010 6.2 9.1
0110 7.3 10.2
1110 8.4 11.3
0001 9.4 12.3
1001 10.3 13.2
0101 11.1 14.0
1101 11.8 14.7
0011 12.5 15.4
1011 13.1 16.0
0111 13.7 16.6
1111 14.3 17.2
Table 3-1. Registered Values with Span Dip Switches Set to 1001 (Trim Span Clockwise)

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3.1.2 Span Calibration
To check the span, put a test weight equal to at least 50% of the full scale and use the Fine Span potentiometer (Figure 2-2 on
page 4) to adjust the corresponding output to the exact value. If the fine adjustment isn't sufficient use the DIP switches of
Coarse Span, then verify the zero output is 0 VDC or 0 mA or 4 mA again. If necessary adjust the Zero and then reapply the test
weight and recheck the span output. Repeat this operation until the output is correct.
Set DIP Switches 1-4 corresponding to the input mV to obtain 20 mA or 10 VDC.
Set DIP Switches of Coarse Span (Figure 2-2 on page 4):
0 = OFF 1 = ON
3.2 Calibration Through Simulator
Use a cell simulator and a voltmeter to display in 0.1 of a millivolt.
1. Connect the simulator to the SCT-3300.
2. Measure the mV input on the terminals 4 (+) and 3 (-) and verify 0 mV; verify the mA or VDC output is 0-4 mA or 0 VDC
(in accordance with the model used) otherwise use the DIP switches of coarse zero and the fine zero to set the output
to those values (usually the DIP switch 1 is in position ON).
3. Measure the supply (about 10V +/- 3%) on the terminals 1 (-) and 2 (+).
4. Multiply this value by the rated output of the cells (mV/V) to obtain the mV value in input, set the simulator to obtain this
value on the terminals 4 (+) and 3 (-).
5. Use the DIP switches and the potentiometer for span full scale to obtain in output 20 mA or 10 VDC.
6. Bring the mV input to zero and check the 4 - 0 mA or 0 VDC output, otherwise adjust the new value.
7. Move the mV input to full scale (load cells supply x rated output) and make sure the output signal is 20 mA or 10 VDC.
8. Adjust the full scale (Fine Span) if necessary.
Position of DIP Switches
(1234)
Input mV to Obtain 10 VDC or 20 mA Output
mV range with potentiometer
set to counterclockwise
mV range with potentiometer
set to clockwise
1111 31.2 19.5
0111 20.8 14.8
1011 15.5 12.0
0011 12.5 10.0
1101 10.3 8.6
0101 8.8 7.5
1001 7.7 6.7
0001 6.9 6.1
1110 6.3 5.6
0110 5.8 5.2
1010 5.3 4.8
0010 4.9 4.5
1100 4.5 4.2
0100 4.2 3.9
1000 3.9 3.7
0000 3.7 3.5
Table 3-2. Registered Values with Zero DIP Switches Set to 0000 (Trim Zero Counterclockwise)