Rice Lake BenchMark Series Supplement

22125
BenchMark Series
Single Point Bench Scales
Installation/Service
Manual
TM

i
Contents
1.0 Introduction.................................................................................................................................. 1
1.1 10"x10" and 12"x12" SL Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 12", 18", and 24" Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 12" x 18" Stainless Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.4 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4.1 10" x 10" and 12" x 12" SL Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4.2 12" x 18" Stainless Steel Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4.3 12", 18" and 24" Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.0 Installation ................................................................................................................................... 4
2.1 Leveling Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Connecting the Load Cell Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.3 Grounding the Scale Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.0 Calibration ................................................................................................................................... 5
4.0 Troubleshooting Guide................................................................................................................. 5
5.0 Load Cell Replacement................................................................................................................ 6
5.1 10"x10" and 12"x12" SL Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.2 12", 18", and 24" Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.0 Load Cell Replacement Table...................................................................................................... 8
7.0 Installing Protective Clamshells ................................................................................................. 8
8.0 Replacement Parts - 10" x 10" and 12" x 12" SL Models ......................................................... 9
9.0 Replacement Parts - 12" Models (Mild Steel Only).................................................................. 10
10.0 Replacement Parts - 12" x 18" SST Model............................................................................... 11
11.0 Replacement Parts - 18" and 24" Models ................................................................................ 12
12.0 BenchMark Series Limited Warranty ........................................................................................ 13
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© 2007 Rice Lake Weighing Systems. All rights reserved. Printed in the United States of America. Specifications subject to
change without notice.
December 2007

Introduction 1
1.0 Introduction
Congratulations on choosing a scale from the
BenchMark™series, the highest-quality single-point
benchtop scale available. The following types of
NTEP-approved BenchMark scales are available: Authorized distributors and their employees can
view or download this manual from the Rice Lake Weighing
Systems distributor site at: www.ricelake.com
• The light-capacity SL series featuring stainless steel construction in 10"x10" and 12"x12" platforms with
capacities from 5 lb to 100 lb.
• A mid-range model with a 12"x18" platform and a cover and frame that are constructed of stainless steel.
This model is available in capacities from 50 lb to 100 lb.
•The medium-capacity series is constructed with stainless steel covers, and mild steel—or optional
stainless steel—frame construction. This series is available in sizes from 12" x 12" up to 24" x 24" in
capacities from 30 lb to 1,000 lb. This manual covers each scale series.
One exciting feature of the BenchMark series is its ability to be converted into a checkweigher. By adding the
neck and head from a CW-80 CheckWeigher to your BenchMark scale, the features of a checkweigher are
available to you. Contact your Rice Lake Weighing Systems distributor for more information.
1.1 10"x10" and 12"x12" SL Models
All seven models of the 10" x 10" and 12"x12" SL series have stainless steel covers and frame systems. All
models use an RL1042 load cell. The 10, 20, 30, 50, and 100 lb models come standard with a potted RL1042 load
cell that offers extra protection against water infiltration but is not designed for washdown use. The 30, 50, and
100 lb models can also be supplied with an RL1140 stainless steel load cell. Extra load cell protection is also
available in optional stainless steel “clamshells” which enclose the load cell. See Section 7.0 for information
about clamshell installation. All load cells come with 10 feet of cable.
Figure 1-1. Overload Springs
The SL series scales use a sensitive 4-point, spring-plate suspension to minimize shock and overload damage
susceptible of light-capacity scales. The system uses a bolt and an overload protection spring at each of four
loading points beneath the top cover (see Figure 1-1). Each spring is set for a specific tension so that it will
compress to prevent overload damage. If a potentially damaging load is placed on a corner of the scale, the spring
at that corner compresses. When the spring compresses, the load is taken off the load cell. This eliminates the
possibility of overloading the load cell. Likewise, if a load more than 150% of total capacity is placed anywhere
on the deck, the springs will compress and remove the load from the load cell.
In addition to the overload protection spring, the SL models incorporate a load cell overload protection screw
beneath the load cell to help prevent overload damage.
To protect the load cell from being accidentally forced upward and damaged by improperly lifting the scale by
the spider, a lift up protection screw is incorporated into the design (see Figure 1-2).
Figure 1-2. Lift up Protection Screw
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2Benchmark Series Installation & Service Manual
1.2 12", 18", and 24" Models
Larger models in the series use mild steel frames and stainless steel deck covers for light washdown with a damp
sponge. All models are available with mild steel or optional stainless steel underbody frame construction. The
standard load cell is either an RL1042 or RL1260, depending on capacity. Options include a stainless steel
RL1140 load cell for 12" x 12" and 12" x 18" models and protective stainless steel clamshells for all models
using RL1042 or RL1260 load cells. All load cells come with 10 feet of cabling.
Figure 1-3. 12" x 12" With Overloads
These medium-capacity bench scales provide overload protection for the load cell by positive stops located
beneath each corner of the top frame (see Figure 1-3). These stops are set at the factory for 100% of scale
capacity. Additional overload protection is provided by an overload screw beneath the load cell to help prevent
shock damage.
1.3 12" x 18" Stainless Steel
The 12" x 18" model has a stainless steel cover and underbody frame to meet USDA requirements and make it
ideal for washdown use. The 12" x 18: comes standard with an RL1042 load cell; a stainless steel load cell is
optional for both the 50 lb and 100 lb models. Extra load cell protection is available with the optional stainless
steel "clamshell" that encloses the load cell. See Section 7.0 for information about clamshell installation. All
locad cells come with 10 feet of cabling.
These medium capacity bench scales provide overload protection with positive stops located beneath each corner
of the top frame. These stops are set at the factory for 100% of scale capacity. Additional overload protection is
provided by an overload screw beneath the load cell to help prevent shock damage.
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Introduction 3
1.4 Specifications
1.4.1 10" x 10" and 12" x 12" SL Models
Load Cell: RL1042-N5 potted single point
(5 lb is not potted)
RL1140 potted single point, stainless
steel load
cell optional on 30, 50, and 100 lb
models
Rated Output: 0.91 mV/V
Maximum Overload: 200%
Overload Protection: Spring loaded spider
Cable Length: 10 ft. (3 m) – 6 wire shielded
Output Impedance (ohms): 350Ω
Compensated
Temperature Range: -10°C/14°F to +50°C/122°F
Safe Temperature Range:-30°C/-22°F to +70°C/158°F
Dimensions/Capacities:
1.4.2 12" x 18" Stainless Steel Model
Load Cell: RL1042-N5 potted single point
RL1140 potted single point, stainless
steel load cell
optional on 50 lb and 100 lb models
Rated Output: 0.91 mV/V
Maximum Overload: 200%
Overload Protection: 5 point, independently adjusted
Cable Length: 10 ft. (3 m) – 6 wire shielded
Output Impedance (ohms): 350Ω
Compensated
Temperature Range: -10°C/14°F to +50°C/122°F
Safe Temperature Range:-30°C/-22°F to +70°C/158°F
Dimensions/Capacities:
1.4.3 12", 18" and 24" Models
Load Cell: 12"x12" and 12"x18":
RL1042-N5 potted single-point
18"x18", 18"x24" and 24"x24":
RL1260-N5 potted single-point
Overload Protection: 5 point, independently adjusted
Cable Length: 10 ft. (3 m) – 6 wire shielded
Rated Output: 0.91 mV/V
Output Impedance: 350Ω
Maximum Overload: 200%
Compensated
Temperature Range: -10°C/14°F to +50°C/122°F
Safe Temperature Range:-30°C/-22°F to +70°C/158°F
Dimensions/Capacities:
Size Capacity Height
10" x 10"/254mm x 254mm 5 lb / 2.3 kg 3.15" / 80 mm
10 lb / 4.5 kg 3.15" / 80 mm
20 lb / 9.1 kg 3.15" / 80 mm
30 lb / 13.6 kg 3.15" / 80 mm
12" x 12"/305mm x 305mm 30 lb / 15 kg 3.25" / 92 mm
50 lb / 25 kg 3.25" / 92 mm
100 lb / 50 kg 3.25" / 92 mm
Table 1-1. 10" x 10" and 12" x 12" SL Model Sizes
Size Capacity Height
12" x 18" / 305mm x 457mm 50 lb / 25 kg 4.00" / 102mm
100 lb / 50 kg 4.00" / 102mm
Table 1-2. 12" x 18" Stainless Steel Model Sizes
Size Capacity Height
12" x 12" / 305mm x 305mm 30 lb / 13.6 kg 3.62" / 92mm
50 lb / 25 kg
100 lb / 50 kg
12" x 18" / 305mm x 457mm 50 lb / 25 kg 3.62" / 92mm
100 lb / 50 kg
18" x 18" / 457mm x 457mm 50 lb / 25 kg 5.25" / 133mm
100 lb / 50 kg
150 lb / 75 kg
200 lb / 100 kg
250 lb / 125 kg
300 lb / 150 kg
500 lb / 250 kg
1000 lb / 500 kg
18" x 24" / 457mm x 610mm 50 lb / 25 kg 5.25" / 133mm
100 lb / 50 kg
150 lb / 75 kg
200 lb / 100 kg
250 lb / 125 kg
300 lb / 150 kg
500 lb / 250 kg
1000 lb / 500 kg
24" x 24" / 610mm x 610mm 100 lb / 50 kg 5.25" / 133mm
150 lb / 75 kg
200 lb / 100 kg
250 lb / 125 kg
300 lb / 150 kg
500 lb / 250 kg
1000 lb / 500 kg
Table 1-3. 12", 18, and 24" Model Sizes

4Benchmark Series Installation & Service Manual
2.0 Installation
2.1 Leveling Scale
Remove the scale from the shipping container and place it in the desired location. Lift off the deck cover and
locate the bubble level. Adjust the four corner feet until the scale is level and all feet contact the support surface
so the scale does not rock. Lock the jam nuts on the feet when the final level is correct.
2.2 Connecting the Load Cell Cable
All models come with 10 feet of color-coded load cell cable. Do not cut this cable. The load cell is
temperature-compensated for an exact cable length of 10 feet.
See your indicator manual to determine the proper load cell cable input connectors. Use the following color
codes to wire the load cell cable.
For 6-wire operation: For 4-wire operation:
* Connect Sense and Excitation wires together if using 4-wire
system without sense leads.
2.3 Grounding the Scale Base
Bench scales can build up a static electricity charge during weighing operations. If powerful enough, this charge
can travel through the load cell cable to the indicator. To prevent this, all bench scales should be adequately
grounded so that static charges and transient electrical surges can drain directly to ground. Recommended
practice is to connect the scale base to an AC ground circuit using at least #12 wire. All BenchMark scales have
either a grounding screw or a hole for such a grounding screw located on the bottom of the lower frame for this
purpose.
6-Wire Color Code Function
Red + Signal
White - Signal
Green + Excitation
Black - Excitation
Blue + Sense
Brown - Sense
Yellow or Bare Shield
Table 2-1. Load Cell Wiring - 6 Wire
4-Wire Color Code Function
Red - Signal
White + Signal
Green and Blue* + Excitation
Black and Brown* - Excitation
Yellow or Bare Shield
Table 2-2. Load Cell Wiring - 4 Wire

Calibration 5
3.0 Calibration
It is recommended that the scale be “exercised” by loading it to near capacity 2 or 3 times before calibration to be
certain that everything is seated. To calibrate your BenchMark:
1. With no load on scale, place the indicator in its calibration mode and perform a zero calibration.
2. Place test weights on platform equal to 70%–100% of scale’s capacity. If several weights are used, they
distribute them evenly around the platform.
3. Perform a span calibration.
4. Remove the test weights and check the zero reading. If necessary, repeat the calibration process.
See the indicator manual for the specific indicator calibration procedure.
4.0 Troubleshooting Guide
Use the following troubleshooting tips for the Benchmark scale if necessary.
Symptom Probable Cause Remedy
No display Power disconnected Connect power
Cable cut or disconnected Repair cable
Signal leads incorrectly wired at indicator Connect according to the manual
Display starts at zero Incorrect load cell cable connections Connect according to the manual
Faulty indicator Service indicator
Erratic Weight display Vibration near the scale Remove the source of the vibration, or
adjust digital averaging of indicator to
minimize erratic display
Scale not level Level the scale
Water damage to the load cell or cable Replace the load cell
Faulty indicator Service the indicator
Loose load cell screws Tighten to correct torque
Faulty load cell Test and replace if necessary
Consistently low weight Indicator not properly adjusted to zero Zero indicator correctly
Scale deck cover binding Obtain adequate clearance
Overload stops set too high Reset the stops correctly
Indicator not calibrated for scale Calibrate the scale
Faulty load cell Test and replace if necessary
Table 4-1. Benchmark Troubleshooting Table

6Benchmark Series Installation & Service Manual
5.0 Load Cell Replacement
5.1 10"x10" and 12"x12" SL Models
1. Unplug AC power from indicator and disconnect load cell cable from indicator.
2. Lift off scale top cover. Locate two upper load cell screws. Use 7/16" wrench to unscrew and remove
those two load cell screws. Do not remove four spring-loaded screws that attach load plate to spider
assembly. Lift off load plate/spider assembly as a unit. Remove spacer between load plate and load cell
and set it aside.
Figure 5-1. Load Cell Mount Diagram
3. Turn scale over and back off overload protection screw one complete turn. Completely unscrew and
remove lift up protection screw.
4. Use 7/16" wrench to unscrew and remove two lower load cell screws. The load cell and cable can now be
removed from scale. Do not lose shim beneath load cell.
5. Thread cable of replacement load cell through rubber grommet. Position load cell on shim and screw in
two lower load cell screws. Torque to 80 in-lb.
6. Replace lift up protection screw by screwing it in until it lightly bottoms, then back it off 1/4 turn.
7. Turn scale right side up. Position spacer on load cell, then place load plate/spider assembly into position.
Screw in two upper load cell screws. Torque to 80 in-lb.
8. Using an accurate caliper, check compressed spring length on four overload springs (Figure 5-2). If
necessary, adjust spring length to specifications shown in Table 5-1. Replace top cover and re-level scale
if necessary.
9. Connect load cell cable to indicator.
10. Recalibrate scale as described in Section 3.0.
11. Adjust overload protection screw on bottom of scale by loading scale to 125% capacity. Place this weight
on top cover, centered on platform. Use a hex wrench to screw in overload protection screw until it
touches load cell, then back off 1/6 turn. Recheck calibration.
Figure 5-2. Spring Height
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Scale Model Spring Length "H"
10 x 10 - 5 Lb 1.06
10 x 10 - 10 Lb .94
10 x 10 - 20 Lb .97
10 x 10 - 30 Lb 1.43
12 x 12 - 30 Lb 1.43
12 x 12 - 50 Lb 1.12
12 x 12 - 100 Lb 1.16
Table 5-1. Overload Spring Length
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Load Cell Replacement 7
5.2 12", 18", and 24" Models
1. Unplug AC power from indicator and disconnect load cell cable from indicator.
2. Lift off scale top cover. Locate upper load cell screws. Depending on model of scale, there will be either
two or four upper load cell screws. Unscrew and remove those load cell screws. Lift off top spider.
Remove spacer plate and set it aside.
Figure 5-3. 12" x 12" Load Cell Mount
3. Loosen four overload stop screws and turn each screw in one turn to provide ample clearance for the new
load cell. Turn scale over and back off overload protection screw one complete turn to provide clearance.
4. Unscrew and remove lower load cell screws. Depending on model of scale, there will be either two or
four lower load cell screws. Remove bottom shim beneath load cell and set it aside. Remove load cell
and cable from scale.
5. Thread cable of replacement load cell through rubber grommet. Position bottom shim directly beneath
load cell and screw in lower load cell screws. Torque to 80 in-lbs for 12" x 12" and 12" x 18" scales, to
120 in-lb for 18" x 18", 18" x 24", and 24" x 24" scales.
6. Turn scale right side up. Position spacer plate on load cell, then place top spider into position. Screw in
four upper load cell screws. Torque to 80 in-lbs for 12" x 12" and 12" x 18" scales, to 120 in-lb for
18" x 18", 18" x 24", and 24" x 24" scales.
7. Connect load cell cable to indicator.
8. Recalibrate scale as described in Section 3.0 of this manual.
9. Adjust overload protection screw on bottom of scale by loading scale to 125% capacity. Place this weight
on top cover, centered on platform. Use a hex wrench to screw in overload protection screw until it
touches the load cell, then back off 1/6 turn. Recheck calibration.
10. To reset corner overload stop screws, load top spider over one corner with approximately 30% of scale
capacity. Adjust screw under that corner to just touch top frame. Place a drop of a non-permanent,
high-strength locking compound such as LOCTITE®on the thread. Back screw off slightly so it is not
touching.
LOCTITE is a registered trademark of the Loctite Corporation
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