Magtrol LMU 212 User manual

Load Monitoring Units
LMU 212 and LMU 217
User’s manual
Via Paolo Uccello 4 - 20148 Milano
Tel [phone] Fax [phone] [email protected] www.dspmindustria.it

First Edition, rev. B – September 2014
While every precaution has been exercised in the compilation of this document to ensure
the accuracy of its contents, Magtrol assumes no responsibility for errors or omissions.
Additionally, no liability is assumed for any damages that may result from the use of the
information contained within this publication.
COPYRIGHT
Copyright ©2008 Magtrol SA. All rights reserved.
Copying or reproduction of all or any part of the contents of this manual without the express
permission of Magtrol is strictly prohibited.

i
The contents of this manual are subject to change without prior notice. Should revisions be necessary, updates to
all Magtrol User’s Manuals can be found at Magtrol’s web site at http://www.magtrol.com/support/manuals.htm
Please compare the date of this manual with the revision date on the web site, then refer to the manual’s Table of
Revisions for any changes/updates that have been made since this edition..
TABLE OF REVISIONS
DATE EDITION CHANGES SECTION
09/12/2014 First Edition rev. B Conguration and Calibration Report updated A.2
07/01/2009 First Edition rev. A 0% hysteresis changed to <0.5% 2.4.4.1 and
2.4.4.2
03 2009 First Edition - -
Revisions To This Manual

ii
Table of Contents
PREFACE................................................................................................................................................................ III
Purpose of This Manual................................................................................................................................................................iii
Who Should Use This Manual......................................................................................................................................................iii
Manual Organization ....................................................................................................................................................................iii
REVISIONS TO THIS MANUAL ................................................................................................................................ I
Table of Revisions ......................................................................................................................................................................... i
TABLE OF CONTENTS ........................................................................................................................................... II
Table of Figures ............................................................................................................................................................................iii
1. INTRODUCTION ................................................................................................................................................. 1
1.1 General information........................................................................................................................................................ 1
1.2 Data Sheet...................................................................................................................................................................... 2
2. INSTALLATION / CONFIGURATION.................................................................................................................. 7
2.1 General information........................................................................................................................................................ 7
2.2 Installation of the LMU 212 and LMU 217 load monitoring units.................................................................................... 7
2.3 Connection of the LMU 212 and LMU 217 load monitoring units................................................................................. 10
2.4 CongurationoftheLoadmonitoringUnit.................................................................................................................... 11
2.4.1 Adaptation of the monitor to the available supply unit................................................................................. 11
2.4.2 Selection of the type of wiring to the strain gauge........................................................................................ 13
2.4.3 Designation of the voltage and current inputs/outputs.................................................................................. 14
2.4.4 Configuration of the detection chains ........................................................................................................... 14
2.4.5 Selection of the pass band............................................................................................................................. 19
2.4.6 Selection of the sensitivity range .................................................................................................................. 19
2.4.7 Selection of the application........................................................................................................................... 20
2.4.8 Division of the transducer signal or the input voltage Ui/p by two ................................................................ 21
2.4.9 Use without transducer.................................................................................................................................. 22
3. CALIBRATION .................................................................................................................................................. 23
3.1 Electrical calibration (standard) .................................................................................................................................... 23
3.1.1 Zero adjustment on the voltage output.......................................................................................................... 23
3.1.2 Zero adjustment on the current output .......................................................................................................... 24
3.1.3 Sensitivity adjustment on the voltage output ................................................................................................ 24
3.1.4 Sensitivity adjustment on the current output................................................................................................. 24
3.1.5 Adjustment of the detection thresholds......................................................................................................... 25
3.2 Quick Calibration .......................................................................................................................................................... 27
3.2.1 Operations preceding a quick calibration...................................................................................................... 27
3.2.2 Calibration procedure.................................................................................................................................... 27
3.3 Calibration of the built-in test equipment (B.I.T.E.) ....................................................................................................... 28
4. APPLICATIONS ................................................................................................................................................ 29
4.1 Using one or several load monitoring units .................................................................................................................. 29
4.1.1 Using one single load monitoring unit LMU 212 ......................................................................................... 29
4.1.2 Using one single load monitoring unit LMU 217 ......................................................................................... 30
4.1.3 Using three load monitoring units LMU 212................................................................................................ 31
4.2 Using transducers in parallel ........................................................................................................................................ 32
4.3 Operational check of the measuring chain ("OK") ........................................................................................................ 32
4.3.1 Checking the transducer signal transmission to the load monitoring unit .................................................... 32
4.3.2 “OK” philosophy........................................................................................................................................... 33

iii
Table of ContentsMagtrol Load Monitoring Units LMU 212 & 217
4.5 Permanent supply check .............................................................................................................................................. 33
4.6 Using B.I.T.E. signal ..................................................................................................................................................... 34
5. REPAIR ............................................................................................................................................................. 36
5.1 Trouble-shooting........................................................................................................................................................... 36
APPENDIX A :
CONFIGURATION AND CALIBRATION REPORT ............................................................................................... 37
A.1 LMU 212....................................................................................................................................................................... 38
A.2 LMU 217....................................................................................................................................................................... 39
APPENDIX B : CE CONFORMITY DECLARATION ............................................................................................. 41
MAGTROL LIMITED WARRANTY......................................................................................................................... 42
Claims 42
TABLE OF FIGURES
2. INSTALLATION / CONFIGURATION
Fig. 2–1 Installation of the LMU 212 load monitoring unit .....................................................................................11
Fig. 2–2 Installation of the LMU 217 load monitoring unit .....................................................................................12
Fig. 2–3 Stuffing gland (overall and exploded view) ................................................................................................13
Fig. 2–4 Load monitoring unit board with location of the selection elements .........................................................14
Fig. 2–5 Jumper and switch configuration................................................................................................................15
Fig. 2–6 LMU grounding when using a 230, 115 or 48 VAC supply ........................................................................16
Fig. 2–7 Wiring types ................................................................................................................................................17
Fig. 2–8 Location of the SWA micro-switches ..........................................................................................................18
Fig. 2–9 Examples of switching delays.....................................................................................................................20
Fig. 2–10 Potentiometer location on the load monitoring unit board ......................................................................21
Fig. 2–11 Location of the SWB micro-switches on the load monitoring unit board.................................................22
Fig. 2–12 Location of the SWC micro-switches on the load monitoring unit board.................................................23
Fig. 2–13 Location of the transducer presence simulation jumpers .........................................................................25
3. CALIBRATION
Fig. 3–1 Location of the potentiometers on the load monitoring unit board............................................................26
Fig. 3–2 Location of the micro-switches SWC3 and SWC4 on the load monitoring unit board...............................28
Fig. 3–3 Location of the relays REL1 and REL2 on the load monitoring unit board...............................................29
4. APPLICATIONS
Fig. 4–1 Using one single load monitoring unit LMU 212.......................................................................................32
Fig. 4–2 Using one single load monitoring unit LMU 217.......................................................................................33
Fig. 4–3 Using three load monitoring units LMU 212 .............................................................................................34
Fig. 4–4 Using one single load monitoring unit LMU 212.......................................................................................35
Fig. 4–5 Permanent supply check LED .....................................................................................................................36
Fig. 4–6 B.I.T.E. control input terminals ..................................................................................................................38

iv
Preface
PURPOSE OF THIS MANUAL
This manual has all the necessary information regarding the installation, connection, calibration and
use of Magtrol's LMU 212 and LMU 217 load monitoring unit. To achieve maximum capability
and ensure proper use of the system, please read this manual in its entirety before operating. Keep
the manual in a safe place for quick reference whenever a question should arise.
WHO SHOULD USE THIS MANUAL
This manual is for users who want to install and use the load monitoring unit LMU 212 or LMU
217 for processing data generated by load measuring pins. The user should have suitable technical
training in mechanics and electronics so as to allow him to install and use this load monitoring unit
without risk.
MANUAL ORGANIZATION
This section gives an overview of the structure of the manual and the information contained within it.
Some information has been deliberately repeated in different sections of the document to minimize
cross-referencing and to facilitate understanding through reiteration.
Summary of the different chapters :
Chapter 1 : INTRODUCTION – Contains the technical data sheet of the load monitoring units
LMU 212 and LMU 217 and gives its technical characteristics as well as a brief
overview of the application fields.
Chapter 2 : INSTALLATION / CONFIGURATION – Contains the mounting and configuration
explanations for the load monitoring unit LMU 212 or LMU 217.
Chapter 3 : CALIBRATION – Describes the calibration procedures of the zero, sensitivity
and relays detection level of the load monitoring unit as well as of test signal level
(B.I.T.E.).
Chapter 4 : APPLICATIONS – Describes examples of applications for one or several load
monitoring units. Explains the use of the test signal (B.I.T.E.).
Chapter 5 : REPAIR – Contains solutions to problems encountered with LMU series load
monitoring units.
Appendix A : CONFIGURATION AND CALIBRATION REPORT – Contains the configuration
and calibration report of the LMU 212 and LMU 217 which must be filled in with
great care when installing the load monitoring unit.
Appendix B : CE CONFORMITY DECLARATION – Contains the CE conformity declaration
of the MAGTROL LMU series load monitoring units.

v
Magtrol Load Monitoring Units LMU 212 & 217 Preface
WARNINGS
SYMBOLS USED IN THIS MANUAL
The following symbols and type styles may be used in this manual to highlight certain parts of the text:
Note: This is intended to draw the operator’s attention to complementary
information or advice relating to the subject being treated. It
introduces information enabling the correct and optimal function
of the product.
Caution: this is used to draw the operator’sattention to information,
direCtives, proCedures, etC. whiCh, if ignored, may result in
damage to the material being used. the assoCiated text desCribes
the neCessary preCautions to take and the ConsequenCes that
may arise if these preCautions are ignored.
WARNING! ThIs INTRoduces dIRecTIves, pRoceduRes,
pRecAuTIoNARy meAsuRes, eTc. WhIch musT be
execuTed oR folloWed WITh The uTmosT cARe
ANd ATTeNTIoN, oTheRWIse The peRsoNAl sAfeTy
of The opeRAToR oR ThIRd pARTy mAy beAT RIsk.
The ReAdeR musT AbsoluTely TAke NoTe of The
AccompANyING TexT, ANd AcT upoN IT , befoRe
pRoceedING fuRTheR.
RISK OF ELECTROCUTION
CAUTION
WARNING : THE INSTALLATION AND THE CALIBRATION IS RESERVED TO THE
QUALIFIED STAFF. PLEASE CONSULT THIS MANUAL BEFORE ANY MANIPULATION
AND FOLLOW ATTENTIVELY THE INSTRUCTIONS.
THE CABLING MUST BE DONE WITH POWER SUPPLY SWITCHED OFF.
THE CALIBRATION REQUIRES TO OBSERV SECURIZED ELECTRICAL WORKING
METHODS.
PLEASE PAY ATTENTION IN DESCRIPTIVE PRESENT ON THE DEVICE
The lightning ash with arrowhead symbol within an equilateral
triangle is intended to alert the user to the presence of uninsulated
dangerous voltage within the product’s enclosure that may be
of sucient magnitude to constitute a risk of electric shock to persons.
.
The exclamation point symbol within an equilateral triangle is
intended to alert the user to the presence of operating
and maintenance instructions in the literature accompanying
the appliance.

1
1.1 GENERAL INFORMATION
The LMU series load monitoring units have been specially designed for applications using load pins
with strain gauge sensors. This range of monitoring units offer a large flexibility for the implementation
of load measuring systems.
Three models of load monitoring units are available :
• LMU212:basicmodel
• LMU217:modelcombiningtwoLMU212placedsidebyside
• LMU216:modelcombiningoneLMU212andacontrolmodule.
Note : Only the two first models - the LMU 212 and LMU 217 - will be
described in this manual. The LMU 216 is the subject of one manual
entirely dedicated to this unit.
The specially robust design of these units allows monitoring load limits in the most challenging
environments.
1. Introduction

2
Magtrol Load Monitoring Units LMU 212 & 217Chapter 1 – Introduction
1.2 DATA SHEET
LMU
Data Sheet
LMU Series
Load Monitoring Units
1
www.magtrol.com
MAGTROL
FEATURES
• Forusewithfull-bridgestraingaugetransducers
(sensitivity0.5to4mV/V)
• Voltageinputforloadsummationorforindividualuse
(withoutsensor)
• 2to4leveldetectorswithrelayoutputcontacts
• 0–20mAor4–20mADCcurrentoutput
• ±10Vvoltageoutput(s)
• Providescontinuousdetectionofsignallinefailureand
shortcircuits(«OK»signals)
• Includesintegratedtestequipment(B.I.T.E.)with
continuouspowersupplymonitoring
• CompatibletoCEStandards
• IP65aluminumhousing
Features of LMU 216 only:
• 4leveldetectorswithoutputcontacts,2ofthemwith
programmablememory
• Summerwith4inputs
• Tarefunction
• Optionalbalancingandcomparatorsub-module
DESCRIPTION
TheMagtrolLoadMonitoringUnitisspeciallydesignedfor
straingaugetransducerapplications.Specificallydeveloped
forusewithMagtrol load measuring pins and load-force-
weightsensors,theLMUSeriesprovidesexcitationcurrent
andamplifiestheoutputsignaloffull-bridgestraingauges.
LoadMonitoringUnitsareflexibleandfullyconfigurable
duetoDIP-switchesandjumperswhichallowtheunitto
beeasilyinstalled—nosolderconnectionsarerequired.The
leveldetectorsandtheoutputscanbededicatedeithertothe
full-bridgeinput,tothevoltageinput,ortothesumofboth
(see “Application Selection” at the top of page 3).Abuilt-in
auto-diagnosticsystemdetectsanyshortcircuitsorsignalline
failures,thus allowing the system to be used in applications
where safety is important.Ifaproblemisdetected,both
relaysaredeactivatedandtheoutputvoltage(respective
current)changesto>10VDCand>20mA.
TheLMUisfullycompatiblewithEuropeanCommunity(CE)
standards.ItsIP65aluminumhousingallowsthesystemto
beusedinharshenvironments.UsingSMD(surfacemounted
device)technology,theLMUallowsthemaximumperformance/
priceratioforstraingaugetransducermonitoring.
LMU 212 LMU 217 LMU 216
Description 1 transducer input 2 transducer inputs (2 × LMU 212) 1 transducer input
Voltage Output 1 × 0–10 V 2 × 0–10 V 3 × 0–10 V
Current Output 1 × 0–20 mA or 4–20 mA 2 × 0–20 mA or 4–20 mA 1 × 0–20 mA or 4–20 mA
Relays 2 4 4
Summation 2 signals 3 signals 4 signals
LMU 217
LMU 216
LMU 212
MODEL COMPARISON

3
Magtrol Load Monitoring Units LMU 212 & 217 Chapter 1 – Introduction
2
MAGTROL
Specifications
* NOTE: To guarantee precise calibration, the impedance of the
connected unit must be indicated at time of order. If this
value is unknown, an impedance of 1 MΩwill be used
for calibration. The resulting deviation will be ≤5%
with an impedance of ≥2 kΩor ≤1% with ≥10 kΩ.
LMU
INPUT CHARACTERISTICS
Power Supply
Voltage
• 115–230 VAC and 20–32 VDC
jumper selectable
• 48 VAC fixed
Maximum Current
Current
Fuse rating
70 mA for 230 VAC 80 mAT
150 mA for 115 VAC 160 mAT
250 mA for 20 VDC 400 mAT
350 mA for 48 VAC 400 mAT
Bridge signal
Supply Voltage 10 VDC
Max. Possible Current 140 mA DC
Sensitivity 0.5 to 4 mV/V
Max. Dynamic
Component of Bridge
Signal
±45 mVDC
Max. Common Mode
Voltage on Input ±10 V
Voltage Input for Summation of Another Load
Input Impedance 70 kΩ
Max. Input Signal
(dynamic) ±10 V
Signal Division by 2 DIP-switch selectable
Use Without Transducer Jumper selectable
Input for Auto-diagnostic Feature (OK I/P)
Type Active if short circuited
OUTPUT CHARACTERISTICS
Relay Outputs
Number of Relays
LMU 212: 2
LMU 217: 4 (2 per input)
LMU 216: 4
Relay Behavior Configurable with DIP-switch
Max. Current per Contact 4 A at 250 V AC
3 A at 30 V (0,5 A at 48 V DC)
Max. Voltage per
Contact
AC : 250 Veff
DC : 48 VDC
Contact Rating 90 W or 1000 VA
Insulation Voltage Contact-contact: 750 Veff
Contact-coil: 1.5 kVeff
Lifetime min. 105 (at 4 A, 250 V AC)
108 (unloaded)
Contact Resistance < 20 mΩ
Current Output
Output Type Current generator
Nominal Current Range 0 to 20 mA DC
Max. Current Range 0 to 25 mA DC
Max. Load < 500 Ω for Imax = 20 mA
Output Impedance > 50 kΩ
Voltage Output
Max. Dynamics ±10 V ≡ EM
Max. Load
≥10 kΩ (ε≤0.5%) [≥1 kΩ (ε≤5%)] *
Output Impedance 50 Ω (in series)
Output for Auto-diagnostic Feature (OK O/P)
Type Open collector
TRANSFER CHARACTERISTICS
Voltage Transfer Ranges (∆UI/P / ∆UO/P)
Range 1 2 3
Bridge Sensitivity
[mV/V]
0.42 to 0.78
(0.6)
0.7 to 1.3
(1)
1.2 to 2.2
(1.7)
Voltage Transfer
(gain)
2380 to 1280
(1670)
1428 to 769
(1000)
833 to 455
(588)
Adjustment Range ±30% ±30% ±30%
Range Selection Selectable using DIP-switches
Signal Division by 2
DIP-switch selectable (the
available sensitivities then
moves from 0.84 to 4.4 mV/V
according to the selected
range)
Measuring Chain Zero
Adjustment
Coarse adjustment using multi-
turn potentiometer: equivalent
to ±10 V/output for range 3
Fine adjustment using multi-
turn potentiometer: 5% of the
coarse adjustment
Temperature drift of the
transfer function ≤200 ppm/°C
T
emperature drift of the
measuring chain zero
value
≤200 ppm of FSD/°C for
0.5 mV/V at the input ≡ ≤1
µV/°C
Current transfer range
Sensitivity Range with
Multi-turn Potentiometer
± 20% of FSD on U
O/P
Nominal Current Range 0 to 20 mA DC
Max. Current Range 0 to 25 mA DC
Zero Adjustment Range ± 5 mA DC for IO/P ≥ 5 mA DC
Selectable low-pass filter
Filter Type Butterworth
Filter Order 2
-3 dB Cut-off Frequency
Selectable using DIP-switches
(0.3 Hz, 1 Hz, 3 Hz, 10 Hz,
100 Hz)
Level detectors
Number of Detectors 1 per relay
Level Adjustment Range
-10 to +10 VDC using multi-turn
potentiometer (measured on
voltage output)
Hysteresis <0.5% or ≈ 5%
(DIP-switch selectable)
Detection Indication < or > (DIP-switch selectable)
Switching Delay
Delay Adjustment Range
0.01 to 4.25 seconds
(adjustment for every relay by
multi-turn potentiometer)

4
Magtrol Load Monitoring Units LMU 212 & 217Chapter 1 – Introduction
3
MAGTROL
Specifications
Basic conFiguration
The LMU Load Monitoring Unit offers unlimited configuration possibilities. It is impossible to list them all in this data sheet.
Please contact Magtrol or one of its subsidiaries or sales agents to discuss your specific applications.
Relay Output Contacts
• LMU 212/117: 2 per channel (RE1, RE2)
• LMU 216: 4 (RE1, RE2, RE3, RE4)
Strain Gauge
Transducer
LMU
Load
Monitoring
Unit Current Output 0–20 mA or 4–20 mA
Voltage Input ±10 V
"OK" Output (OK O/P)
"OK" Input (OK I/P)
Voltage Output(s) ±10 V
• LMU 212: 1
• LMU 216: 3
• LMU 217: 2
Power Supply
• 115–230 VAC (50/60 Hz)
• 20–32 VDC
• 48 VAC
LMU 216 only:
Summer with 4 Voltage Inputs (±10 V)
LMU
aDDitional lMu 216 Functions
SUMMER
Number of Inputs 4 (UA, UB, UC and UD)
Input Voltage ±10 V
Output Voltage
UE1 = (UA + UB ± UC ± UD)X
X adjustable between 0.25 and
10
LATCHING
Control Using DIP-switches
Reset Signal RESET REL3, RESET REL4
CALIBRATION CIRCUIT
Principle
Volatile* digital memory at 12 bits
(memory reset at startup), the stored
digital value is substracted from the
input signal after D/A conversion
*Current interruptions lasting for less
than 30 ms do not lead to the loss of the
stored calibration value
Resolution 1/4096 of the selected range
Storing Time < 2 s
Output Impedence < 200 Ω
Acceptable Load
Resistance ≤ 20 kΩ
TRANSFER CHARACTERISTICS (cont.)
Application selection
Output specific application:
REL1 det. REL2 det. UO/P I O/P
A, B or A+B A, B or A+B A, B or A+B A, B or A+B
A = bride signal; B = voltage input
MECHANICAL CHARACTERISTICS
Housing
Material Aluminum
Stuffing glands
Type and number LMU 212: 3 × PG 11
LMU 216 and 217: 6 × PG 11
Material Nickel-plated brass
Terminal strip
Type MK8 (screw and connection at
45°)
Max. Area of
Connecting Wire
AWG 20 to 16
Cross section: 0.5 to 1.5 mm²
(0.00077 to 0.0023 in²)
ENVIRONMENTAL CHARACTERISTICS
Operating Temperature -40° C to +80° C
Storage Temperature -45° C to +85° C
Protection Class IP 65
Vibration and Shock According to IEC 68.2
EMC According to EN 61326-1
and EN 61326-2-3
SAFETY CHARACTERISTICS
B.I.T.E. test signal
(Built In Test Equipment)
Signal type
Load simulation on request
(calibrated during the
installation)
Control Logic signal, active low, CMOS/
TTL compatible
Reliability
MTBF > 1,500,000 hours

5
Magtrol Load Monitoring Units LMU 212 & 217 Chapter 1 – Introduction
4
MAGTROL
Dimensions
lMu 216 anD lMu 217
lMu 212
LMU
N N P P P N N
J
M
K
E
D
C
H
F
B
A
mm
A287
B272
C190
D175
E≈18
F≈220
H12
J10
K90
M27
N30
P35
mm
A122
B82
C220
D204
E≈16
G20.75
J13.4
K90
L≈1.5
M28
N47
C
D
G
E
B
A
M
N
K J
L
Mounting screw
M6x30
Sealed diecast
aluminum box
Stuffing glands
Ø cable: 5 to 12 mm
Stuffing glands (max. PG 11)
Ø cables : 5 to 12 mm
Mounting screw
M6x30
OVERHEAD VIEW SIDE VIEW
FRONT VIEW
SIDE VIEW
Sealed diecast
aluminum box
OVERHEAD VIEW
Model Weight
LMU 212 2 kg
Model Weight
LMU 216 4 kg
LMU 217 3.750 kg

6
Magtrol Load Monitoring Units LMU 212 & 217Chapter 1 – Introduction
LMU
Due to the continual development of our products, we reserve the right to modify specifications without forewarning.
MAGTROL INC
70 Gardenville Parkway
Buffalo, New York 14224 USA
Phone: [phone]
Fax: [phone]
E-mail: [email protected]
MAGTROL SA
Centre technologique Montena
1728 Rossens / Fribourg, Switzerland
Phone: [phone]
Fax: [phone]
E-mail: [email protected]
www.magtrol.com
Subsidiaries in:
Great Britain
Germany • France
China • India
Worldwide Network
of Sales Agents
Ordering Information
LMU-US 04/10
ORDERING INFORMATION
LOAD MONITORING UNIT P/N 224 - -000-
Model
•LMU 212 (1 input) 212
•LMU 216 (1 input) 216
•LMU 217 (2 inputs) 217
Supply
•115–230 VAC (50/60 Hz) or 20–32 VDC 0
•48 VAC (50/60 Hz) 4
Balancing comparator option (only for LMU 216)
LMU 216:
•No 11
•Ye s 61
LMU 212:
•No (not available) 11
LMU 217:
•No (not available) 11
Configurated and calibrated?
•No (standard) (blank)
•Yes (according to application and Magtrol Configuration and Calibration Protocol) C
ORDERING INFORMATION

7
2. Installation / Configuration
2.1 GENERAL INFORMATION
It is essential to follow and apply the installation and configuration procedure described in this
chapter to avoid any perturbation of the measuring signal processed by an incorrectly installed LMU
212 or LMU 217.
Note : The procedures described in this chapter do not cover all mounting
and connection possibilities. However, they can be used as a guide
for further customer specific applications. In case of doubt, the user
should not hesitate to contact Magtrol's customer service to find a
solution offering the best guaranty for optimal measuring accuracy.
2.2 INSTALLATION OF THE LMU 212 AND LMU 217 LOAD MONITORING UNITS
Note : For optimal operation, the load monitoring unit should be run at
temperatures between -40° C and +80° C.
Both load monitoring units LMU 212 and LMU 217 being structurally very close to each other, their
mounting and the connection procedures are very similar :
1. Select a suitable mounting place free of vibrations. An instrument support, for instance,
offers excellent results.
2. Trace the location of the 4 screw taps on the mounting surface.
3. Drill and tap the 4 holes for the M6 mounting screws. The taps depth must be approximately
15 mm.
4. Remove the cover of the load monitoring housing. The LMU 212 cover is being fixed with
4 screws, the LMU 217 cover with 6 screws (see figures 2-1 and 2-2).
5. Position the housing on the mounting surface and fasten the 4 M6 x 30 mounting screws by
applying a fastening torque corresponding to the type of screw used.
6. Configure and calibrate the load monitoring unit if not already done according to the
procedure described in this chapter.
7. Carry out the necessary electrical connection and make sure that the housing stuffing glands
are water-tight.
8. Insert a copy of the calibration protocol (see Appendix A) into the load monitoring unit
housing before placing the cover back onto the housing and fastening its screws.

8
Magtrol Load Monitoring Units LMU 212 & 217Chapter 2 – Installation / Configuration
M6 washer
Housing M6 x 30 fixing screw
Load monitoring unit
housing
Tap on the mounting
surface
Load monitoring unti cover
Cover fixing screw
82
204
Fig. 2–1 Installation of the LMU 212 load monitoring unit

9
Magtrol Load Monitoring Units LMU 212 & 217 Chapter 2 – Installation / Configuration
M6 washer
M6 x 30 housing
fixing screws
Load monitoring unit housing
Taps on the
assembly surface
Load monitoring unit cover
Fixing screw for cover
272
175
Fig. 2–2 Installation of the LMU 217 load monitoring unit

10
Magtrol Load Monitoring Units LMU 212 & 217Chapter 2 – Installation / Configuration
2.3 CONNECTION OF THE LMU 212 AND LMU 217 LOAD MONITORING UNITS
The LMU 212 and LMU 217 load monitoring units are fitted with stuffing glands maintaining the
connection cables and securing the tightness of the unit's housing. To pass the cables through the
stuffing glands simply apply the following procedure :
1. Uninsulate the conductors of the different cables.
2. Remove the housing cover after having unscrewed the fixing screws.
3. Pass the cables through the stuffing glands as shown on figure 2–3 :
a. Unscrew the hex nut by rotating it counterclockwise. The main body of the stuffing
gland should not be removed from the unit's housing.
b. Extract the internal and external gasket from the hex nut . Both gaskets are used
to compensate for the different cable diameters. Push the internal gasket to extract it
from the external gasket .
c. Pass the cable through the hex nut , the internal gasket (when used), the external
gasket , the sealing ring and the main body .
d. Reassemble the stuffing gland and coat the front part of the external gasket  with
silicone (see figure 2–3) before screwing the hex nut  onto the main body . Tighten
the hex nut in such a way that the internal gasket and/or the external gasket 
protrudes, so as to provide the degree of watertightness required.
e. Ensure also that the cable is held firmly in the stuffing gland.
Caution : donot damage the gaskets with Cutting objeCts. CheCk that no
foreign bodies have slid between the elements of the stuffing
gland. degrease the surfaCe of the Cable whiCh will Come into
ContaCt with the gasket. the seal of the stuffing gland Cannot
be guarantied if these instruCtions are not followed.
Protruding gasket 
Assembled stuffing gland
Cable
Hex nut
Internal gasket
External gasket
Sealing ring
Main body
Only grease
the front part
    
 
Fig. 2–3 Stuffing gland (overall and exploded view)
4. Connect the conductors of the various cables to the load monitoring unit terminals.
5. Put the cover back on the load monitoring unit and tighten up its six screws.

11
Magtrol Load Monitoring Units LMU 212 & 217 Chapter 2 – Installation / Configuration
2.4 CONFIGURATION OF THE LOAD MONITORING UNIT
Note : The asterisks (¶) correspond to the standard configuration of the
LMU 212 version 0XX and LMU 217 version 0XX, that is to say
the basic uncalibrated modules.
The configuration of the LMU 212 and LMU 217 load monitoring units include all start-up operations
which are necessary to achieve a trouble free operation. This ranges from the supply voltage to
the selection of the application, the sensor connection, the energising mode of the relays and their
delay time, the selection of the pass-band and the sensor sensitivity. As a reminder: the LMU 217
is composed of two LMU 212.
2.4.1 AdAptAtion of the monitor to the AvAilAble supply unit
2.4.1.1 Supply voltage
Before connecting the LMU 212 or LMU 217 load monitoring unit, select its operating voltage by
correctly positioning the jumper (DC or AC voltage) and then, in case of an AC supply, choosing
the correct voltage by means of the switch. Finally choose the supply fuse rating.
WARNING! The moNIToRING uNIT cAN be seRIously
dAmAGed If NoT desTRoyed, If ThIs AdvIce Is NoT
folloWed.
The information given in figures 2–4 to 2–6 and in the table on the next page allows the user to
select the operating voltage of the load monitoring unit, to choose the supply fuse and to assign the
supply terminals.
Fig. 2–4 Load monitoring unit board with location of the selection elements
1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
23 24 21 22
Terminal
Supply fuse
Operating voltage selection
jumper and switch

12
Magtrol Load Monitoring Units LMU 212 & 217Chapter 2 – Installation / Configuration
1. Place the jumper according to the selected supply mode (see figure 2–5) :
- 'DC' for a DC type supply with a voltage between 20 and 32 VDC
- 'AC' for an AC type supply (230 VAC, 115 VAC or 48 VAC)
2. In case of an AC supply position the switch on (see figure 2–5) :
- '230 V' for an AC voltage of 230 VAC
- '115 V' for an AC voltage of 115 VAC
- for operating voltages of 48 VAC or 20 to 32 VDC the position of the switch is irrelevant.
Fig. 2–5 Jumper and switch configuration
3. Check the rating of the fuse inserted in its support according to the following table:
Operating
voltage
Supply terminals Fuse Switch
0 V (18) N (19) P (20)
¶230 VAC earth neutral phase 80 mAT 230 V
115 VAC earth neutral phase 160 mAT 115 V
48 VAC earth neutral phase 400 mAT irrelevant
20 - 32 VDC 0 V — 20 - 32 V 400 mAT irrelevant
A fuse of each rating is supplied with each load monitoring unit.
WARNING! foR sAfeTy ReAsoNs IT Is ImpoRTANT To secuRe
The sTAbIlITy of The supply uNIT used ANd
RespecT The opeRATING volTAGe selecTed oN
The lmu.
Note : Do not forget to report the designation of the collected external
signals connected to the supply terminal on the configuration and
calibration form (see Appendix A).
Operating voltage
20 to 32 VDC
Operating voltage
48 VAC
Operating voltage
115 VAC
Operating voltage
230 VAC

13
Magtrol Load Monitoring Units LMU 212 & 217 Chapter 2 – Installation / Configuration
4. When using a 230 VAC, 115 VAC or 48 VAC supply always connect the LMU to the ground as
shown on figure 2–6 :
B
C
B
A
N.Buri
A.Rappo
Corinne B.
14.03.97
14.03.97
14.03.97
Pos.17 removed !
Pos.5 and 6 changed; pos. 9 removed !
Pos. 18 added
N.B.
N.B.
N.B.
C.S.
C.S.
C.B.
02076
01062
97133
12.12.02
03.12.01
02.07.97
LMU 112
LOAD MONITORING UNIT
1:5
LMU212mise à terre
1
3
2
1
3
2
A
B
C
C
D
D
Approved
Checked
Drawn
DRAWING N°
Scale
Repl. for:
Repl. by :
Appr.
Finish:
Material:
Tolerances: ± mm to 50mm, ± mm over 50mm
Drawn
PM
Date
Rev.
1
2
3
4
5
6
THE INFORMATION DISCLOSED HEREIN WAS ORIGINATED BY AND IS THE PROPERTY OF MAGTROL SA.
MAGTROL SA RESERVES ALL PATENT PROPRIETARY, DESIGN, USE, SALE, MANUFACTURING AND
REPRODUCTION RIGHTS THERETO.
Fig. 2–6 LMU grounding when using a 230, 115 or 48 VAC supply
Connect the earth wire to the ground screw and the LMU terminal n° 18 to the ground screw.
WARNING! WheN usING A 48 / 115 / 230 vAc supply AlWAys
mAke suRe ThAT The lmu housING Is AdequATely
coNNecTed To The GRouNd!
2.4.2 selection of the type of wiring to the strAin gAuge
The choice of the type of wiring depends on the length of the cable between the LMU and the strain
gauge transducer, on the impedance of the transducer and the linear resistance of the cable.
If the linear resistance of the cable is ≤0,1 W/m, the impedance of the strain gauge transducer is
≥200 Wand the length of the cable is ≤100 m, the wiring of type 1 can be selected (see figure 2–7).
The wiring of the type 2 of figure 2–7 applies to cable lengths of more then 100 m or when the cable
length has been changed after the calibration of the load monitoring unit.