Rice Lake Benchmark LP User manual

BenchMark® LP
Low-Profile Bench Scale
Installation Manual
PN 104742 Rev DOctober 23, 2020

An ISO 9001 registered company
© 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
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.
© Rice Lake Weighing Systems ● All Rights Reserved i
1.0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.0 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1 Site Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2 Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3 Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.4 Summing Board Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.5 Electrical Interface to Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.0 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 Mechanical Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 Corner Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.3 Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.0 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.2 Load Cell Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.3 Wiring to Summing Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.0 Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.0 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

BenchMark LP Low-Profile Bench Scale
Rice Lake continually offers web-based video training on a growing selection
of product-related topics at no cost. Visit www.ricelake.com/webinars
ii Visit our website www.RiceLake.com

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 the BenchMark LP Low-Profile
Bench Scale.
Manuals and additional resources are available from the Rice Lake Weighing Systems website at www.ricelake.com
Warranty information can be found on the website at www.ricelake.com/warranties
The BenchMark LP is a four-cell, low-profile scale. Features include:
• Available in sizes from 18'' x 18'' (.46 m x .46 m) to 36'' x 36'' (.91 m x .91 m)
• Capacities from 100 lb to 1000 lb (45 kg to 453 kg)
• Fully electronic low-profile load receivers
• Four corner-mounted, FM-approved planar beam load cells
• Signal-trim summing board for any necessary corner corrections, mounted under a stainless steel cover that can be
sealed for Legal-for-Trade
• All models come pre-trimmed; corner corrections should not be necessary
• Load cell cables are held down with replaceable cable ties near each corner
• Adjustable feet to compensate for minor floor irregularities
• Holes located in the lower frame to be used for permanent mounting applications
1.1 Overview
Model Designations
The model identification label is located on the side of the frame. Include both model number and serial number when ordering
replacement parts.
Electrical Grounding
For systems where the scale is connected to a 115 VAC circuit, the indicator must be directly connected to an earth ground with
a ground interface cable of no more than 3 Ω resistance throughout its length.
Load Cells
• Four Rice Lake RLBLP (planar beam)
• Rated Excitation: 5-15 VDC
Grade Level Requirement
The supporting surface of the scale (encompassing four feet) must be level within 1/4'' of horizontal.
End Load Capacity
End load capacity is 60% of full scale capacity.
Part No. Capacity
Platform Dimensions
L x W x H1 (H2*) Torque To
97662 100 lb (50 kg) 18'' x 18'' x 2.63'' ( 1.67'') 50 lb per inch
97663 250 lb (125 kg) 18'' x 18'' x 2.50'' (1.74'') 125 lb per inch
97664 500 lb (250 kg) 18'' x 18'' x 2.69'' (1.93'') 125 lb per inch
97665 100 lb (50 kg) 24'' x 24'' x 2.66'' (1.69'') 50 lb per inch
97666 250 lb (125 kg) 24'' x 24'' x 2.83'' (2.07'') 125 lb per inch
97667 500 lb (250 kg) 24'' x 24'' x 3.02'' (2.26'') 125 lb per inch
97668 500 lb (250 kg) 30'' x 30'' x 3.02'' (2.26'') 125 lb per inch
97669** 1,000 lb (500 kg) 30'' x 30'' x 3.47'' (2.70'') 20 lb per foot
97670 500 lb (250 kg) 36'' x 36'' x 3.02'' (2.26'') 125 lb per inch
97671** 1,000 lb (500 kg) 36'' x 36'' x 3.47'' (2.70'') 20 lb per foot
* Height without adjustable leveling feet
** Non-NTEP or Measurement Canada Approved
Table 1-1. Platform Dimensions and Capacity

BenchMark LP Low-Profile Bench Scale
2 Visit our website www.RiceLake.com
1.2 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.
Failure to heed may result in serious injury or death.
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.
Before opening the unit, ensure the power cord is disconnected from the outlet.
Keep hands, feet and loose clothing away from moving parts.
DANGER
WARNING
CAUTION
IMPORTANT
WARNING

Installation
© Rice Lake Weighing Systems ● All Rights Reserved 3
2.0 Installation
This section provides an overview of BenchMark LP Low-Profile Bench Scale installation instructions.
2.1 Site Preparation
The scale must not be loaded beyond its capacity, even momentarily. Select a site where there is no chance of overload
weights crossing the platform. Avoid areas where the scale might receive damaging side impacts from wheels or forklift tines,
shock damage from falling objects or where water may damage the scale.
The interface cable between the scale and the indicator must be protected against crushing, cutting or moisture damage. If the
chosen site has such potential dangers, some method of protection, such as running the cable in conduit, will be necessary.
In operation, the scale must be level within 1/4''. Either choose a site where the floor is close to this standard to avoid excessive
shimming, or modify the floor at the chosen site to meet this standard.
2.2 Unpacking
Immediately after unpacking, visually inspect the BenchMark LP to ensure all components are included and undamaged.
If any parts were damaged in shipment, notify Rice Lake Weighing Systems and the shipper immediately.
Remove the four overload stops on the underside of the scale (Figure 2-1).
Figure 2-1. Remove Overload Stops
2.3 Assembly
1. Remove the black scale cover.
2. Remove the summing board cover in the center of the scale.
3. Wire the homerun cable (Section 2.4 on page 4).
4. Properly secure the cable with nylon ties (supplied).
5. Using the bubble level next to the summing board, ensure the scale is level.
6. Replace the black scale cover and use the four mounting screws to secure it in place.
7. If necessary, perform a corner correction (Section 3.2 on page 6).
8. Replace the summing board cover.
9. Replace the black center cover.
10. Set the stainless steel cover on the scale.
Overload Stops Overload Stops

BenchMark LP Low-Profile Bench Scale
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2.4 Summing Board Security
After an NTEP inspector has examined the unit, a security cable will be installed on the summing board cover. These cables
prevent the summing board from being tampered with by unauthorized individuals. If these cables are removed, NTEP
Certification will become void.
Figure 2-2. Summing Board Security Cable
2.5 Electrical Interface to Indicator
20' of 6-wire cable (used to connect the scale to the weight indicator) is supplied with each scale. Both ends have the wires
stripped and tinned. Use the following instructions to access the summing board.
1. Remove the stainless steel platform.
2. Remove the lid in the center of the platform, revealing the summing board cover plate.
3. Remove security cables (this will void NTEP Certification).
4. Remove screws on the summing board cover plate and remove lid.
Wire Connections
Remove the summing board cover and connect the wires to the indicator terminal (Figure 2-3). To connect the indicator wires to
the appropriate connectors, push in the quick connect lever with a non-conductive tool. When holding the lever, insert the
appropriate wire into the exposed wire opening.
Figure 2-3. Summing Board Indicator Terminal
JP4
JP2
PT4 PT3 JP3
PT1
EXP
PT2
JP1
1
CELL4
1
CELL1
1
CELL3
1
CELL2
IND
-EX
-SI
SHD
+SI
+EX
M
R
N
I
-SI
S2C
I
A
G
+EX
+SI
-SI
SHD
-EX
I
S
G
A
L
T+SI
M
S
I
N
L
T
R
+EX
-EX
-SI
SHD
+SI
+EX
+SI
-EX
-SI
SHD
-EX
SHD
+SE
-SE
+EX

Installation
© Rice Lake Weighing Systems ● All Rights Reserved 5
Cable Routing
The cable must be routed to the indicator in a manner that will protect the cable from damage. When planning cable routing,
leave a loose coil of excess cable under the scale to facilitate future lifting of the scale for servicing or cleaning.
1. When the interface cable is protected and in its final position, complete connections to the indicator. See indicator
installation manual for wiring information.
2. If necessary, trim corners as described in Section 3.2 on page 6.
3. Check all strain relief for tightness.
4. Secure with nylon ties.
Figure 2-4. Homerun Cable Wired to Summing Board

BenchMark LP Low-Profile Bench Scale
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3.0 Calibration
This section provides an overview of BenchMark LP Low-Profile Bench Scale calibration instructions.
3.1 Mechanical Adjustments
To accommodate minor floor unevenness, scale feet can be used to adjust scale height up or down a fraction of an inch.
Carefully lift each corner of the scale and adjust the feet by hand until all feet are contacting the floor equally. Be sure to support
the scale while adjusting the feet. Jam nuts are supplied for locking the feet in place.
When height adjustments are complete, recheck the level of the deck with a spirit level. The deck must be level within 1/4''.
3.2 Corner Correction
All assembled BenchMark LP scales are delivered with the summing board corner-trimmed. Corner trimming is only necessary
after replacing a load cell.
To calibrate the scale, the output from each load cell must be matched by adjusting the signals with potentiometers at the
summing board—a process known as trimming.
1. Remove the summing board cover and identify the correct load cell terminal corresponding to each corner.
See Figure 4-3 on page 10 for scale deck corner numbering.
2. Calibrate the indicator (it does not need to be exact) using a test weight that is 25% of the scale capacity.
Example: Use a 25 lb test weight for 100 lb models, or a 250 lb test weight for 1000 lb models.
3. Remove weight from the scale.
4. Zero the indicator.
5. Turn all four potentiometers fully clockwise (shaded areas of Figure 3-1) to increase the reading until a clicking sound
is heard from each potentiometer. This ensures the maximum signal from each load cell.
Figure 3-1. Trim Potentiometers
6. Zero the indicator and place 25% of scale capacity (using calibrated test weights) over each load cell in turn.
7. Record the value displayed on the indicator after the test weight is placed on each corner (directly over the load cell)
without allowing the weight to overhang the sides. Allow scale to return to zero each time to check for friction or other
mechanical issues. Select the load cell which has the lowest value as the reference point. This cell will not be trimmed.
8. Replace the same test load over each cell in turn. Using the corresponding potentiometer, trim each cell down to equal
the reference load cell. As corner corrections are somewhat interactive, check all cells again for repeatability.
If necessary, repeat Step 5 and Step 6.
JP4
JP2
PT4 PT3 JP3
PT1
EXP
PT2
JP1
1
CELL4
1
CELL1
1
CELL3
1
CELL2
IND
-EX
-SI
SHD
+SI
+EX
M
R
N
I
-SI
S2C
I
A
G
+EX
+SI
-SI
SHD
-EX
I
S
G
A
L
T+SI
M
S
I
N
L
T
R
+EX
-EX
-SI
SHD
+SI
+EX
+SI
-EX
-SI
SHD
-EX
SHD
+SE
-SE
+EX
Jumper Locations JP1 and JP2 are Shaded
Jumper Locations JP3 and JP4 are Shaded
Potentiometers
Potentiometers