Rice Lake Benchmark LP User manual

104742
Benchmark LP
Low-Profile Bench Scale
Installation Manual
TM

Contents
Contents ................................................................................................................................................... i
About This Manual ................................................................................................................................... 1
1.0 Introduction.................................................................................................................................. 1
2.0 Installation ................................................................................................................................... 2
2.1 Site Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.2 Unpacking and Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.3 Summing Board Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.4 Electrical Interface to Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.0 Adjustments and Calibration ....................................................................................................... 5
3.1 Mechanical Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2 Corner Correction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.3 Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.0 Service Information ..................................................................................................................... 7
4.1 Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.2 Periodic Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.3 Load Cell Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.3.1 Load Cell Wiring to Summing Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.4 Replacement Load Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Benchmark LP Limited Warranty............................................................................................................. 9
© 2008 Rice Lake Weighing Systems. All rights reserved. Printed in the United States of America.
Specifications subject to change without notice.
April 2008
Technical training seminarsare available through Rice Lake Weighing Systems.
Course descriptionsand datescan be viewed at www.ricelake.com or obtained by
calling 715-234-9171 and asking for the training department.

ii Benchmark LP Manual

Introduction 1
About This Manual
This manual is intended for use by service technicians
responsible for installing and servicing the
Benchmark™LP low-profile bench scale.
Warning
Some procedures described in this
manual require work inside the summing
board enclosure. These procedures are
to be performed by qualified service
personnel only.
Authorized distributors and their employees
can view or download this manual from the
Rice Lake Weighing Systems distributor
site at www.ricelake.com.
1.0 Introduction
The Benchmark LP is a four-cell, low-profile scale.
Features include:
• Available in sizes from 18 in. x 18 in (.46 m x
46 m) to 36 in x 36 in (.91 m x .91 m).
• Capacities from 100 to 1000 lbs (45 - 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 can be used to allow leveling
of the scale to compensate for minor floor
irregularities.
• Holes are located in the lower frame to be
used for permanent mounting applications.
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 3Ωresistance throughout its length.
Load Cells
• Four (4) 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 1/4in of horizontal.
End Load Capacity
60% of full scale capacity.
Platform Dimensions, Capacity, and Torque Specs
Table 1-1. Platform dimensions and capacity
*Non-NTEP
Part Number Capacity Platform Dimensions (LxWxH) To r qu e To
97662 100 lbs. 18” x 18” x 1.67” (2.63“ with leveling feet) 50 LBSPER IN
97663 250 lbs. 18” x 18” x 1.74” (2.50“ with leveling feet) 125 LBSPER IN
97664 500 lbs. 18” x 18” x 1.93” (2.69“ with leveling feet) 125 LBSPER IN
97665 100 lbs. 24” x 24” x 1.69” (2.66“ with leveling feet) 50 LBSPER IN
97666 250 lbs. 24” x 24” x 2.07” (2.83“ with leveling feet) 125 LBSPER IN
97667 500 lbs. 24” x 24” x 2.26” (3.02“ with leveling feet) 125 LBSPER IN
97668 500 lbs. 30” x 30” x 2.26” (3.02“ with leveling feet) 125 LBSPER IN
97669* 1000 lbs. 30” x 30” x 2.70” (3.47“ with leveling feet) 20 LBSPER FT
97670 500 lbs. 36” x 36” x 2.26” (3.02“ with leveling feet) 125 LBSPER IN
97671* 1000 lbs. 36” x 36” x 2.70” (3.47“ with leveling feet) 20 LBSPER FT

2Benchmark LP Manual
2.0 Installation
Standard installation of the Benchmark™LP floor scale consists of the following steps:
• Select a site
• Check levelness and smoothness of site
• Unpack scale
• Adjust the four feet on the scale
• Connect cable to summing board and
indicator
• Calibrate the unit
2.1 Site Preparation
The scale must not be loaded beyond its capacity, even momentarily. Do not select a site where overweight loads
would have to maneuver to avoid crossing the platform. Avoid areas where the scale might receive damaging
side impacts from wheels or forklift tines, or shock damage from falling objects. Avoid areas 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 1/4inch. 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 and Assembly
1. Remove all packing material and inspect scale for visible damage caused during shipment.
2. Remove the four overload stops on the underside of the scale, shown in Figure 2-1.
Overload
Stops
Overload
Stops
Figure 2-1. Overload Stops to be Removed (4)
3. Remove the black scale cover.
4. Remove the summing board cover in the center of the scale.
5. Wire the homerun cable. Refer to instructions in Section 2.3 on page 3.
6. Properly secure the cable with nylon ties (supplied).
7. Using the bubble level next to the summing board, ensure the scale is level.
8. Replace the black scale cover and use the four mounting screws to secure it in place.
9. If necessary, perform a corner correction. See Section 3.2 on page 5.
10. Replace the summing board cover.
11. Replace the black center cover.
12. Set the stainless steel cover on the scale.

Installation 3
2.3 Summing Board Security
After an NTEP inspector has examined the unit, he/she will install security cables on the summing board cover.
These cables prevent the summing board from being tampered with by an unauthorized individual. If these
cables are removed, NTEP Certification will become void.
Figure 2-2. Summing board cover with security cables installed
2.4 Electrical Interface to Indicator
Twenty feet of 6-wire cable to connect the scale to the weight indicator is supplied with each scale. Both ends
have the wires stripped and tinned.
To access the summing board,
1. Remove the stainless steel platform.
2. Remove lid in the center of the platform, revealing the summing board coverplate.
3. Remove security cables (this will void NTEP Certification).
4. Remove screws on the summing board coverplate 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 small screwdriver or
ballpoint pen. When holding the lever, insert the appropriate wire into the exposed wire opening.
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
Figure 2-3. Summing board indicator terminal

4Benchmark LP Manual
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 5.
3. Check all strain relief for tightness.
Figure 2-4. Homerun cable wired to summing board and secured with nylon ties

Adjustments and Calibration 5
3.0 Adjustments and Calibration
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. Adjust the feet by hand (lift the scale corner slightly with a pry bar) until all feet are contacting the floor
equally. Jam nuts are supplied for locking the feet in place.
When height adjustments are complete, recheck 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 (labeled CELL 1, CELL 2, and so on). See Figure 4-3 on page 8 for scale deck corner numbering.
2. The indicator must be connected and calibrated approximately, but it need not indicate the exact weight
value. A test weight will be required. The recommended test weight for all Benchmark™LP models is
25% of scale capacity: for example, 25 lbs for 100-lb models, 250 lbs for 1000-lb models.
3. With no weight on the scale, zero the indicator.
4. 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.
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
Potentiometers
Jumper Locations
JP1 and JP2
Shaded
Jumper Locations
JP3 and JP4
Shaded
Potentiometers
Figure 3-1. Trim Potentiometers
5. Zero the indicator and place 25% of scale capacity using calibrated test weights over each load cell in
turn.
6. Record the value displayed on the indicator after the test weight is placed in turn on each corner (directly
over the load cell) without allowing the weight to overhang the sides. Allow the scale to return to zero
each time to check for friction or other mechanical problems. Select the load cell which has the lowest
value as your reference point. This cell will not be trimmed.
7. 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 steps 5 and 6.

6Benchmark LP Manual
3.3 Calibration Procedure
Refer to the indicator manual to determine correct calibration procedures.
It is recommended that the scale be "exercised" before calibration to be certain that everything is seated.
1. Load the scale to near capacity two or three times.
2. With no load on the scale, place the indicator in its calibration mode and perform a zero calibration.
3. Place test weights on the platform not exceeding the scale's full capacity. If several weights are used,
they should be evenly distributed around the platform.
4. Perform a span calibration.

Service Information 7
4.0 Service Information
4.1 Troubleshooting Guide
System does not operate—no display
• Power disconnected: Check and reconnect.
• Indicator fuse blown. Replace fuse. Check for
cause.
• Interface cable cut or disconnected: Repair.
•Signal leads incorrectly installed at indicator:
Install according to indicator installation manual
Display stays at zero
• Indicator faulty: Service indicator
•Load cell connections faulty: Check cable
connections in summing board and at indicator
Erratic weights
• Vibration near scale: Remove source of
vibration or move scale.
• Platform not level to within 1/4in: Level
scale by adjusting feet or shimming if
necessary.
• Load cell or cable water damage: Replace.
• Debris under load cells or platform: Clean.
• Indicator faulty: Use simulator to test
indicator for stability. Service indicator.
Consistently high or low weights
• Indicator not properly adjusted to zero: Zero
the indicator according to indicator manual.
• Platform binding: Obtain adequate clearance
for free platform movement.
• Indicator not calibrated: Calibrate according
to indicator manual and Section 3.3
• Load cells faulty: Test and replace load cells
if necessary.
• Feet touching deck underside: Adjust feet
downward to provide clearance.
4.2 Periodic Maintenance
The space beneath the platform must be periodically
cleaned to prevent debris buildup.
Caution
Do not attempt to use scales with load
cells that are not hermetically sealed in
washdown applications. Water damage
is a common cause of failure in
non-hermetically-sealed load cells. Use care with high
pressure steam washdowns for hermetically-sealed
load cells. The steam may not damage the load cells,
but the elevated temperatures may cause incorrect
readings until the unit cools to room temperature.
4.3 Load Cell Replacement
Replacement load cells can be ordered from Rice
Lake Weighing Systems according to the part
numbers in Table 4-2 on page 8. Refer to Table 1-1 on
page 1 for torque settings.
1. Remove defective load cells.
2. Disconnect load cell cable from summing
board and cut cable ties.
14
23
Figure 4-1. Load Cell Arrangement
3. When the cable is freed, pull cable out of the
scale.
4. Lay out each load cell near the corner where it
is to be installed.
5. Attach the cable from each load cell along the
frame and into the summing board as shown
in Figure 4-1.
NOTE: In Figure 4-1, both the scale and the summing board
are viewed from the top. To verify correct load cell/summing
board terminal matching, see the numbers on the terminals
inside the summing board.
6. Check that the threaded holes for the load cell
screws are free of debris. Use compressed air
to blow out holes if necessary.

8Benchmark LP Manual
7. Position load cells with capacity label and
load cell wires facing up, and loosely install
the hex head cap screws (provided).
8. Route the load cell cables along the frame to
the summing board.
9. Secure the cable in position with the
adhesive-backed cables tied supplied in the
hardware kit. See Figure 4-2 for an
illustration of load cell and cable placement.
NOTE: Do not cut load cell cables.
Figure 4-2. Load cell and wire placement
10. Corner correction trimming and calibration is
necessary after load cell replacement. Follow
the instructions in Section 3.2 and
Section 3.3.
4.3.1 Load Cell Wiring to Summing Board
The four load cells are each wired to their respective
terminals in the summing board according to the
corner numbering system shown in Figure 4-3 and the
coloring code in Table 4-1.
34
1
2
Hole for homerun cable
Figure 4-3. Corner numbering (top view)
Table 4-1. Load Cell Wiring
Cable Color Code Summing Board Terminal
Green + Excitation
Black - Excitation
White + Signal
Red - Signal
4.4 Replacement Load Cells
Table 4-2. Replacement load cells
Capacity of Scale Load Mount Load Cell
100 lbs 96823 100272
250 lbs 96824 104645
500 lbs 96825 100273
1000 lbs 96826 100274

9
Benchmark LP Limited Warranty
Rice Lake Weighing Systems (RLWS) warrants that all RLWS equipment and systems properly installed by a
Distributor or Original Equipment Manufacturer (OEM) will operate per written specifications as confirmed by
the Distributor/OEM and accepted by RLWS. All systems and components are warranted against defects in
materials and workmanship for two years.
RLWS warrants that the equipment sold hereunder will conform to the current written specifications authorized
by RLWS. RLWS warrants the equipment against faulty workmanship and defective materials. If any equipment
fails to conform to these warranties, RLWS will, at its option, repair or replace such goods returned within the
warranty period subject to the following conditions:|
• Upon discovery by Buyer of such nonconformity, RLWS will be given prompt written notice with a
detailed explanation of the alleged deficiencies.
• Individual electronic components returned to RLWS for warranty purposes must be packaged to prevent
electrostatic discharge (ESD) damage in shipment. Packaging requirements are listed in a publication,
“Protecting Your Components From Static Damage in Shipment,” available from RLWS Equipment
Return Department.
• Examination of such equipment by RLWS confirms that the nonconformity actually exists, and was not
caused by accident, misuse, neglect, alteration, improper installation, improper repair or improper
testing; RLWS shall be the sole judge of all alleged non-conformities.
• Such equipment has not been modified, altered, or changed by any person other than RLWS or its duly
authorized repair agents.
• RLWS will have a reasonable time to repair or replace the defective equipment. Buyer is responsible for
shipping charges both ways.
• In no event will RLWS be responsible for travel time or on-location repairs, including assembly or
disassembly of equipment, nor will RLWS be liable for the cost of any repairs made by others.
THESE WARRANTIES EXCLUDE ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED,
INCLUDING WITHOUT LIMITATION WARRANTIES OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE. NEITHER RLWS NOR DISTRIBUTOR WILL, IN ANY EVENT,
BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES.
RLWS AND BUYER AGREE THAT RLWS’ SOLE AND EXCLUSIVE LIABILITY HEREUNDER IS
LIMITED TO REPAIR OR REPLACEMENT OF SUCH GOODS. IN ACCEPTING THIS WAR-
RANTY, THE BUYER WAIVES ANY AND ALL OTHER CLAIMS TO WARRANTY.
SHOULD THE SELLER BE OTHER THAN RLWS, THE BUYER AGREES TO LOOK ONLY TO
THE SELLER FOR WARRANTY CLAIMS.
No terms, conditions, understanding, or agreements purporting to modify the terms of this warranty shall have any legal effect
unless made in writing and signed by a corporate officer of RLWS and the Buyer.
© 2008 Rice Lake Weighing Systems, Inc. Rice Lake, WI USA. All Rights Reserved.
RICE LAKE WEIGHING SYSTEMS • 230 WEST COLEMAN STREET • RICE LAKE, WISCONSIN 54868 •USA