Rice Lake CLS Series User manual

CLS-Series
Cargo Lift Scale
Service Manual
211569 Rev B
January 10, 2022

Contents
About This Manual ................................................................................................................................... 1
1.0 Introduction.................................................................................................................................. 1
1.1 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.0 Load Cell Replacement................................................................................................................ 2
2.1 Required Tools for Replacing a Load Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3.0 Junction Box Replacement ....................................................................................................... 12
4.0 Lithium-Ion Battery Charge and Replacement .......................................................................... 17
4.0.1 Lithium-Ion Battery Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.0.2 Charging the Lithium-Ion Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.0.3 Calibrating the Lithium-Ion Battery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.0.4 Battery Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.1 Wireless Battery Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.1.1 Installing Wireless Option on Existing Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.1.2 Battery Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.2 Battery Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.0 Board Replacement ................................................................................................................... 21
5.1 CLS-420 CPU Board Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.1.1 Cable Grounding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.1.2 DC Power Wiring Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.1.3 Serial Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
5.1.4 Board Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
5.2 CLS-920i CPU Board Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.2.1 Enclosure Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.2.2 Cable Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.2.3 Cable Grounding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.2.4 Serial Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.2.5 Digital I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.2.6 Installing Option Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.2.7 Enclosure Reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.2.8 CPU Board Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.2.9 Fuse Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5.2.10 Battery Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5.2.11 Parts Kit Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5.2.12 Downloading CLS Configuration and User Program Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.0 Replacement Parts .................................................................................................................... 38
6.0.1 CLS 420 Indicator Replacement Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
6.0.2 CLS-920 Replacement Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
6.1 CLS-Series Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
©Rice Lake Weighing Systems. All rights reserved. Printed in the United States of America.
Specifications subject to change without notice.
Version 1.0, May 16, 2013
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.

ii CLS-Series Service Manual
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 1
About This Manual
This manual is intended for use by individuals responsible for servicing the CLS-920i and the CLS-420 Cargo Lift
scale.
This manual contains technical instructions and procedures for servicing the CLS Series scales and covers
information on load cell replacement, junction box replacement, replacement parts and troubleshooting procedures.
Any repairs to the indicator include instructions on CPU board and fuse replacement.
This manual does not attempt to cover actual unpacking, installation and operating procedures as they are covered
in the CLS-920i Installation Manual, PN 96312, and CLS-420 Installation Manual, PN 96483.
1.0 Introduction
The CLS Series Cargo Lift scale is a rugged, dependable cargo lift scale that can withstand many years of use.
When mounted on a forklift, the CLS Series can weigh, transfer and collect data in one efficient operation. It saves
operator time, equipment costs and eliminates the middle step.
The CLS Series is used with either Rice Lake’s 920i®HMI digital weight indicator or the 420 digital weight
indicator.
Figure 1-1. CLS Series Cargo Lift Scale
The following sections of this manual deal with any servicing issues that might arise with this product.
Areas described include:
• Load cell replacement
• Junction box/board replacement
• CPU board replacement
• Troubleshooting

2CLS-Series Service Manual
1.1 Safety
Safety Signals
Safety Symbol Definitions:
Important
CAUTION
WARNING
DANGER
Indicates an imminently hazardous situation that, if not avoided, will result in death or serious injury.
Indicates a potentially hazardous situation that, if not avoided could result in death or serious injury, and
includes hazards that are exposed when guards are removed.
Indicates a potentially hazardous situation that, if not avoided may 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
WARNING
Do not operate or work on this equipment unless you have read and understand the instructions and
warnings in this manual. 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. Proper care is your
responsibility.
Failure to heed may result in serious injury of death.
Some procedures described in this manual require work inside the power/communication box. These procedures are to
be performed by qualified service personnel only.
Take all necessary safety precautions when installing the scale carriage including wearing safety shoes, protective eye
wear, and using the proper tools.
DO NOT allow minors (children) or inexperienced persons to operate this unit.
DO NOT operate without all shields and guards in place.
DO NOT jump on the scale.
DO NOT use for purposes other then weight taking.
DO NOT place fingers into slots or possible pinch points.
DO NOT use any load bearing component that is worn beyond 5% of the original dimension.
DO NOT use this product if any of the components are cracked.
DO NOT exceed the rated load limit of the unit.
DO NOT make alterations or modifications to the unit.
DO NOT remove or obscure warning labels.
DO NOT use near water.
Keep hands, feet and loose clothing away from moving parts.

Load Cell Replacement 2
2.0 Load Cell Replacement
This section describes procedures for replacing the load cell should it need to be changed. A replacement parts kit
is available (PN 97883), see Section 6.1 for parts included.
Following the instructions below for a seamless and easy load cell replacement.
Take all necessary safety precautions when installing or replacing the scale parts including wearing safety
shoes, protective eye wear, and using the proper tools.
WARNING
2.1 Required Tools for Replacing a Load Cell
The following list of tools is necessary for replacing a load cell on the CLS Series Scale. Ensure that you have these
necessary tools handy.
Table 2-1. Required Tools for Replacing a Load Cell
Part # Item Description
96196 Modified box wrench (included in kit PN 97883)
Crescent wrench
3/4” Socket wrench, with extensions
Hammer
1-1/8” wrench for overload stop
Chisel
Allen wrench for overload stops
Digital voltmeter (capable of reading millivolts)
Torque wrench
Pry bar
Note
Adequate light is necessary to change the load cell. Try to position the forklift close to a good source of natural
light or if not possible, have a good source of lighting available.
Use the following steps to replace a load cell.
1. Raise the forklift carriage just slightly for forklift tine removal.
2. Slide the fork lift tines to the middle of the carriage to allow for removal of tines and set tines aside.
Slide tines to the middle of scale carriage
Figure 2-1. Forklift Tine Removal

#1 Upper Hex Nut
#2 Upper Hex Nut
#3 Spherical Washer Set
#4 Upper Block
#5 Spherical Washer Set
#6 Hex Nut
#7 Jam Nut
#8 Flexure Rod
#9 Jam Nut
#10 Load Cell
#11 Jam Nut
#12 Flexure Rod
#13 Jam Nut
#14 Hex Nut
#15 Spherical Washer Set
#16 Lower Block
#17 Spherical Washer Set
#18 Hex Nut
#19 Hex Nut
Modied
Wrench
3CLS-Series Service Manual
Figure 2-2. Load Cell Assembly Reference Parts
3. Raise the fork lift carriage to a comfortable working height for the load cell replacement.
4. Remove the top hex nut (#1) with a socket wrench.
Note
It’s okay if the load cell slightly rotates up against the front or back plate of the scale.
Figure 2-3. Removal of Hex Nut (Item #1 in Figure 2-2)

Load Cell Replacement 4
5. Loosen jam nut from the upper block using the special modified box wrench (PN 96196 - supplied with
load cell replacement kit) shown in Figure 2-2.
6. Loosen jam nut (#13) from the lower block.
7. Remove the top hex nut (#2) and the top spherical washer set (#3).
8. Loosen the two bottom hex nuts (#18 and #19) with a socket wrench.
Figure 2-4. Loosen and Remove Bottom Hex Nut (#18 and #19 in Figure 2-2)
Note
It’s okay if the load cell slightly rotates up against the front or back plate of the scale.
9. Remove the bottom hex nuts (#18 and #19) and the bottom spherical washer set (#17).
10. Loosen the hex nut located under the upper block (#6).
11. Loosen the jam nut located on top of the load cell (#9).
12. Loosen the hex nut (#14) located on top of the lower block.
13. Loosen the hex nut (#11) on the lower side of the load cell.
14. Remove the bottom flexure rod (#12) and the top flexure rod (#8) sliding the remaining washer sets (#5
and #15) with it.
15. Disconnect the load cell cable from the junction box. Refer to Section 3 for steps.
16. Loosen cable clips and remove the load cell.
.
Ensure flexure rod
threads are free of
debris and paint by
running a nut the full
distance of the rod.
Figure 2-5. Remove Flexure Rod with Nuts and Washers
17. Check the flexure rod threads for smooth operation by running a nut the full distance of the rod making
sure it does not get stuck anywhere along the way. If so, clean off any paint using a wire brush and oil.

5CLS-Series Service Manual
18. Oil the spherical washers using a standard machine shop oil.
Detach load
cell clip away
from back
plate of scale
using a large
screwdriver.
Figure 2-6. Load Cell Cable Clips
19. Back off upper and lower overload stops using a 1-1/8" wrench.
Overload stops
looking at top view.
Figure 2-7. Overload Stops Illustrated on a 34" Carriage
20. Position a new load cell with its cable facing towards the center and opening of the S-beam facing the
flexures.
Load cell cable should
face towards the center
of the scale.

Load Cell Replacement 6
21. Install the top and bottom flexure rod with hardware ensuring that the flexure rod be oriented with the short
thread of rod facing nearest the load cell.
Short threads
facing nearest
the load cell
Figure 2-8. Installing Flexure into Scale
22. Insert the load cell and thread flexure rods into top and bottom of the load cell making sure the appropriate
hex nuts, jam nuts, and spherical washers are in the correct order per Figure 2-2.
23. Screw in the rod and tighten jam nut but leave approximately two threads exposed outside of the jam nut.
Do both the top and bottom of the load cell.
24. Use hex nuts to position the load cell in the center of the mounting blocks with an equal amount of flexure
rod on top and bottom of the load cell.
25. Tighten the jam nuts on top and bottom of the load cell. Make sure they are tight and load cell is
completely vertical to the scale. To accomplish this, you can use a pry bar or chisel to hold the cell straight
as illustrated in Figure 2-9.
Use chisel to hold load cell
straight.
Figure 2-9. Use Chisel to Hold the Load Cell in Straight
26. Install the spherical washer set and hex nut on the bottom flexure rod ensuring that the fat washer is
mounted towards the mounting block.

7CLS-Series Service Manual
Figure 2-10. Install Spherical Washer Set
27. Install a flat bladed screwdriver in upper mounting block between the hole and the flexure rod, forcing the
flexure rod in the direction of the flexures.
Insert flat blade
screwdriver here to help
center the flexure rod
Figure 2-11. Centering the Flexure Rod
28. Use a pry bar or chisel to hold the load cell (bottom half of the cell), straight while using a torque wrench
to tighten the bottom hex nut on the lower mounting block to 110 ft/lb. Install the other hex nut on the
bottom of the flexure rod and torque it to 110 ft/lb.

Load Cell Replacement 8
Figure 2-12. Centering the Load Cell Using a Chisel
Figure 2-13. Tightening the Lower Hex Nut
29. Use the special modified box wrench to tighten the jam nut (#13) on the lower block.
30. Remove the flat bladed screwdriver as used in Step 25 and inspect the flexure rod. The flexure rod needs to
be in the center of the hole. If it is not, use a hammer and an angled diamond chisel to hit the bottom
mounting plate spherical washer set to adjust it to center.
31. Install the spherical washer set (#3) and hex nut (#2) on the top of the upper block.
32. Wire up the load cell cable to the junction box at this time.
33. Make sure that ZTRKBN is set to Off on the indicator.
34. Torque the hex nut (#2) on the upper mounting block until you see 100 lb on the indicator display. Tighten
the lower hex nut (#6) below the upper mounting block using the modified box wrench and try to get the
display as close to zero as possible.
35. Torque the top hex nut (#1) with a torque wrench to 110 ft/lb. Use a pry bar or chisel to ensure the load cell
stays centered while tightening and doesn’t touch the sides of front or back plate
36. Install the final hex nut on the top mounting plate and torque to 110 ft/lb. Use a pry bar or chisel to keep the
load cell centered.
37. Tighten the jam nut on the lower mounting block assembly.
38. Zero out the indicator display.
39. Exercise the scale heel to toe by placing a weight (1000 lb) on the heel then the toe to check if the assembly
was installed correctly. Do this for both sides. If the weight is off, check assemblies.
40. Place a weight in the center of the fork and check side to side values. If they are equal, you are done.
41. Tighten the overload stops when complete.
42. Make sure to set ZTRKBN to On on the indicator.

12 CLS-Series Service Manual
3.0 Junction Box Replacement
The CLS Series scale uses a NEMA 4X polycarbonate junction box. The junction box is located between the front
and back panel of the scale and is covered by a metal cover plate on the top of the scale. Use the following
procedures for replacing a junction box on the CLS Series Cargo Lift Scale.
1. Remove the bolt that holds the top metal cover plate in place which conceals the junction box.
Remove bolt that
holds the top cover
plate on the scale to
access the smart
junction box.
Smart Junction
Box Location
Figure 3-1. Top Cover Plate (scale shown not mounted on the forklift)
2. Remove the top cover plate and set aside.
3. Lift the fork lift to a comfortable working height.
4. Remove the two screws securing the junction box to the scale. See Figure 3-2 for screw location.
Screw
locations
Figure 3-2. Screw Locations

Junction Box Replacement 13
5. Remove the indicator cable from the junction box (not applicable for wireless models).
Remove indicator
cable from junction
box (if using the wired
model)
Remove load cell
cable from junction
box
Figure 3-3. Junction Box Location Inside the Scale (wireless version shown above)
6. Loosen the load cell clips that hold the load cell cable to the scale back frame and their general location
noted in Figure 2-6 on page 5.
7. Slip the junction box downward out of its current location between the front and back plates of the CLS.
8. Using a phillips head screwdriver, open the junction box cover to expose the inside and set the cover aside.
J4 load cell
connector
J5 load cell connector
Bottom Board Information
Figure 3-4. Inside of Junction Box - Bottom Board
The junction box has two boards within the box. To access the bottom board, remove the screws that hold the top
board in place and flip the top board up and back out of the way as the wires that connect the top and bottom boards
are long enough to accommodate this. The bottom board which is shown in Figure 3-4 connects the wiring for both
load cells one and two. Table 3-1 lists the wiring assignments for the bottom board.

14 CLS-Series Service Manual
9. Reconnect the wires to the bottom board per Figure 3-4, Figure 3-5, and Table 3-1 listed below.
Table 3-1. Load Cell Wiring
J4 Wiring Connector
(Cell #1 - the left cell as viewed from the
forklift drivers seat) J4 Function
1+ SIGNAL
2- SIGNAL
3+ EXCITATION
4- EXCITATION
5SHIELD
J5 Wiring Connector
(Cell #2 - the right cellas viewed from the
forklift drivers seat) J5 Function
1+ SIGNAL
2- SIGNAL
3+ EXCITATION
4- EXCITATION
5SHIELD
J8 Wiring Connector
(From the MS Connector)
J8 Function
1+ V (Red)
2- V (Black)
Exits out
to right
cell #2
Exits out to
left cell #1
J4 - Wiring
for the right
load cell #2
as viewed
from the
driver’s seat
J5 - Wiring for
the left load cell
#1 as viewed
from the driver’s
seat
Figure 3-5. Bottom Board Wiring
Once wiring is complete, place the upper board back and secure screws holding the upper board.

Junction Box Replacement 15
Upper/Top Board Information
The second board, or the upper board is pictured in Figure 3-6.
Figure 3-6. Inside of Junction Box - Top Board
The wiring from the bottom board is then brought up to be wired into the top board as shown in Figure 3-6,
connecting into J3 and J6 connectors.
.
Table 3-2. Top Board Wiring Connections
J3 Wiring Connector
(From the MS connector)
Function and (Wire Color)
1TX1 (blue)
2RX1 (white)
3GND (green)
4TX2 (N/C)
5RX2 (N/C)
6GND (N/C)
J6 Wiring Connector
(From the battery - wirless version only)
Function and (Wire Color)
1KEY (N/C)
2POS (red)
3CLOCK (blue)
4DATA (brown)
5TEMP (green)
6NEG (black)
Table 3-2 shows the wiring to the top board connections.
Note
J6 wiring is only used in the wireless version of the CLS series and goes directly to the battery box.

16 CLS-Series Service Manual

Lithium-Ion Battery Charge and Replacement 17
4.0 Lithium-Ion Battery Charge and Replacement
If using a wireless version of the CLS Series Cargo Lift Scale, the CLS scale uses a supplied lithium-ion battery to
supply power to the indicator. The lithium-ion battery is located on the top of the cover plate in a painted enclosure.
Replacement part numbers are as follows:
Table 4-1. Battery Replacement Parts
RLWS Part Number Description
96343 Lithium-Ion Battery
96344 2-Bay Battery Charger
96345 10-Bay Battery Charger
Figure 4-1. Lithium-Ion Battery Location
4.0.1 Lithium-Ion Battery Specifications
Table 4-2. Battery Specifications
Nominal Capacity 6600 mAh
Nominal Voltage 11.1 V
Charging Method Constant Current
Constant Voltage
Charging Voltage 12.6 V
Charging Current 4.0 A
Charging Time 100% @ 8 hours
Ambient Temperature Charge 0º - +40ºC (32º-104ºF)
Discharge -20º - +60ºC (-4º-140ºF)
Storage -20º - +50ºC (-4º-122ºF)
Weight (Maximum) 430 g
Dimensions (Maximum) Depth 22.80 mm
Length 214.0 mm
Volumetric Energy Density 466 Wh/I
Gravimetric Energy Density 167 Wh/kg
Maximum Hours of Charge 24 hours
Nominal Capacity 6600 mAh

18 CLS-Series Service Manual
4.0.2 Charging the Lithium-Ion Battery
The lithium-ion battery comes with a two-bay, level-3 stand alone smart battery charger, a DC power jack, and a
AC power cord as shown in Figure 4-2.
To calibrate the battery
pack, press the button on
front label.
Figure 4-2. Two-Bay Battery Charger and Parts for the Lithium-Ion Battery
The average charge time for the battery is eight hours each.
Use the following steps to charge the battery prior to use:
1. Insert the plug end of the power cable into the DC power jack on the battery charger and the AC plug into
an outlet.
2. Insert battery into the bay.
3. There is one LED indicator in front of each bay which will illuminate to indicate the status of the battery as
follows:
Table 4-3. Battery Charging LED Signals
Signal Description
Off No Battery
Green Flashing Fast Charging
Green Solid Fully Charged
Yellow Flashing Recalibrating
Yellow/Green Alternating Recalibrating
Yellow Solid Standby
Red Flashing Error
4.0.3 Calibrating the Lithium-Ion Battery
In order to keep the battery fuel gauge as accurate as possible, it is necessary to run the pack through a recalibration
cycle on a quarterly basis. To do this, place the battery in the left bay of the charger and press the button on the
front label (see Figure 4-2). This will initiate the recalibration sequence in the left bay only. The process can take
up to nine hours to complete and a recommended recalibration should be done once a month to keep the battery
accurate.
4.0.4 Battery Removal
The lithium-ion battery itself is housed inside of the battery box which is located on the top plate of the scale and is
encased in a foam core protecting it from vibration.
Open Cover
Remove Battery
Figure 4-3. Lithium-ion Battery Removal
Figure 4-3 shows how to pull the lithium-ion battery out of the battery box.