Vega VEGAFLEX 81 User manual

Operating Instructions
TDR sensor for continuous level and
interface measurement of liquids
VEGAFLEX 81
Four-wire 4 … 20 mA/HART
Coax probe
Document ID: 42280

2
Contents
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
Contents
1 About this document ............................................................................................................... 4
1.1 Function ........................................................................................................................... 4
1.2 Target group ..................................................................................................................... 4
1.3 Symbols used................................................................................................................... 4
2 For your safety ......................................................................................................................... 5
2.1 Authorised personnel ....................................................................................................... 5
2.2 Appropriate use................................................................................................................ 5
2.3 Warning about incorrect use............................................................................................. 5
2.4 General safety instructions............................................................................................... 5
2.5 EU conformity................................................................................................................... 6
2.6 NAMUR recommendations .............................................................................................. 6
2.7 Installation and operation in the USA and Canada ........................................................... 6
2.8 Environmental instructions ............................................................................................... 6
3 Product description ................................................................................................................. 8
3.1 Conguration.................................................................................................................... 8
3.2 Principle of operation........................................................................................................ 9
3.3 Packaging, transport and storage................................................................................... 11
3.4 Accessories and replacement parts ............................................................................... 12
4 Mounting................................................................................................................................. 14
4.1 General instructions ....................................................................................................... 14
4.2 Mounting instructions ..................................................................................................... 15
5 Connecting to power supply................................................................................................. 18
5.1 Preparing the connection ............................................................................................... 18
5.2 Connecting..................................................................................................................... 19
5.3 Wiring plan, double chamber housing ............................................................................ 21
5.4 Double chamber housing with VEGADIS-Adapter.......................................................... 22
5.5 Supplementary electronics............................................................................................. 23
5.6 Switch-on phase............................................................................................................. 23
6 Set up with the display and adjustment module ................................................................ 25
6.1 Insert display and adjustment module............................................................................ 25
6.2 Adjustment system......................................................................................................... 26
6.3 Parameter adjustment - Quick setup .............................................................................. 27
6.4 Parameter adjustment - Extended adjustment................................................................ 28
6.5 Saving the parameterisation data................................................................................... 46
7 Setup with PACTware............................................................................................................. 47
7.1 Connect the PC.............................................................................................................. 47
7.2 Parameter adjustment with PACTware............................................................................ 48
7.3 Set up with the quick setup............................................................................................. 49
7.4 Saving the parameterisation data................................................................................... 50
8 Set up with other systems .................................................................................................... 51
8.1 DD adjustment programs ............................................................................................... 51
8.2 Field Communicator 375, 475 ........................................................................................ 51
9 Diagnostics and servicing .................................................................................................... 52
9.1 Maintenance .................................................................................................................. 52
9.2 Diagnosis memory ......................................................................................................... 52

3
Contents
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
9.3 Status messages............................................................................................................ 53
9.4 Rectify faults................................................................................................................... 56
9.5 Exchanging the electronics module................................................................................ 59
9.6 Software update ............................................................................................................. 60
9.7 How to proceed if a repair is necessary.......................................................................... 60
10 Dismount................................................................................................................................. 61
10.1 Dismounting steps.......................................................................................................... 61
10.2 Disposal ......................................................................................................................... 61
11 Supplement ............................................................................................................................ 62
11.1 Technical data ................................................................................................................ 62
11.2 Dimensions .................................................................................................................... 71
11.3 Industrial property rights................................................................................................. 73
11.4 Trademark ...................................................................................................................... 73
Safety instructions for Ex areas
TakenoteoftheExspecicsafetyinstructionsforExapplications.
These instructions are attached as documents to each instrument
with Ex approval and are part of the operating instructions.
Editing status: 2018-11-05

4
1 About this document
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
1 About this document
1.1 Function
This operating instructions provides all the information you need for
mounting, connection and setup as well as important instructions for
maintenance,faultrectication,theexchangeofpartsandthesafety
of the user. Please read this information before putting the instrument
into operation and keep this manual accessible in the immediate
vicinity of the device.
1.2 Target group
This operating instructions manual is directed to trained personnel.
Thecontentsofthismanualmustbemadeavailabletothequalied
personnel and implemented.
1.3 Symbols used
Document ID
This symbol on the front page of this instruction refers to the Docu-
ment ID. By entering the Document ID on www.vega.com you will
reach the document download.
Information, tip, note
This symbol indicates helpful additional information.
Caution: If this warning is ignored, faults or malfunctions can result.
Warning: If this warning is ignored, injury to persons and/or serious
damage to the instrument can result.
Danger: If this warning is ignored, serious injury to persons and/or
destruction of the instrument can result.
Ex applications
This symbol indicates special instructions for Ex applications.
• List
The dot set in front indicates a list with no implied sequence.
→ Action
This arrow indicates a single action.
1 Sequence of actions
Numbers set in front indicate successive steps in a procedure.
Battery disposal
This symbol indicates special information about the disposal of bat-
teries and accumulators.

5
2 For your safety
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
2 For your safety
2.1 Authorised personnel
All operations described in this documentation must be carried out
onlybytrained,qualiedpersonnelauthorisedbytheplantoperator.
During work on and with the device, the required personal protective
equipment must always be worn.
2.2 Appropriate use
VEGAFLEX 81 is a sensor for continuous level measurement.
Youcannddetailedinformationabouttheareaofapplicationin
chapter "Product description".
Operational reliability is ensured only if the instrument is properly
usedaccordingtothespecicationsintheoperatinginstructions
manual as well as possible supplementary instructions.
2.3 Warning about incorrect use
Inappropriate or incorrect use of this product can give rise to applica-
tion-specichazards,e.g.vesseloverllthroughincorrectmounting
or adjustment. Damage to property and persons or environmental
contamination can result. Also, the protective characteristics of the
instrument can be impaired.
2.4 General safety instructions
This is a state-of-the-art instrument complying with all prevailing
regulations and directives.The instrument must only be operated in a
technicallyawlessandreliablecondition.Theoperatorisresponsi-
ble for the trouble-free operation of the instrument.When measuring
aggressive or corrosive media that can cause a dangerous situation
if the instrument malfunctions, the operator has to implement suitable
measures to make sure the instrument is functioning properly.
During the entire duration of use, the user is obliged to determine the
compliance of the necessary occupational safety measures with the
current valid rules and regulations and also take note of new regula-
tions.
The safety instructions in this operating instructions manual, the na-
tional installation standards as well as the valid safety regulations and
accident prevention rules must be observed by the user.
For safety and warranty reasons, any invasive work on the device
beyond that described in the operating instructions manual may be
carried out only by personnel authorised by the manufacturer. Arbi-
traryconversionsormodicationsareexplicitlyforbidden.Forsafety
reasons,onlytheaccessoryspeciedbythemanufacturermustbe
used.
To avoid any danger, the safety approval markings and safety tips on
the device must also be observed and their meaning read in this oper-
ating instructions manual.

6
2 For your safety
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
2.5 EU conformity
ThedevicefullsthelegalrequirementsoftheapplicableEUdirec-
tives.ByaxingtheCEmarking,weconrmtheconformityofthe
instrument with these directives.
YoucanndtheEUconformitydeclarationonourwebsiteunder
www.vega.com/downloads.
Electromagnetic compatibility
Instruments in four-wire or Ex-d-ia version are designed for use in an
industrial environment. Nevertheless, electromagnetic interference
from electrical conductors and radiated emissions must be taken into
account, as is usual with class A instruments according to EN 61326-
1.Iftheinstrumentisusedinadierentenvironment,theelectromag-
netic compatibility to other instruments must be ensured by suitable
measures.
2.6 NAMUR recommendations
NAMUR is the automation technology user association in the process
industry in Germany. The published NAMUR recommendations are
acceptedasthestandardineldinstrumentation.
ThedevicefullstherequirementsofthefollowingNAMURrecom-
mendations:
• NE 21 – Electromagnetic compatibility of equipment
• NE 43 – Signal level for fault information from measuring transduc-
ers
• NE53–Compatibilityofelddevicesanddisplay/adjustment
components
• NE107–Self-monitoringanddiagnosisofelddevices
For further information see www.namur.de.
2.7 Installation and operation in the USA and
Canada
This information is only valid for USA and Canada. Hence the follow-
ing text is only available in the English language.
Installations in the US shall comply with the relevant requirements of
the National Electrical Code (ANSI/NFPA 70).
Installations in Canada shall comply with the relevant requirements of
the Canadian Electrical Code.
2.8 Environmental instructions
Protection of the environment is one of our most important duties.
That is why we have introduced an environment management system
with the goal of continuously improving company environmental pro-
tection.Theenvironmentmanagementsystemiscertiedaccording
to DIN EN ISO 14001.
Pleasehelpusfullthisobligationbyobservingtheenvironmental
instructions in this manual:
• Chapter "Packaging, transport and storage"

7
2 For your safety
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
• Chapter "Disposal"

8
3 Product description
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
3 Product description
3.1 Conguration
Thetypelabelcontainsthemostimportantdataforidenticationand
use of the instrument:
2
1
12
13
14
15
11
10
5
3
6
4
7
8
9
Fig. 1: Layout of the type label (example)
1 Instrument type
2 Product code
3 Approvals
4 Power supply and signal output, electronics
5 Protection rating
6 Probe length (measurement accuracy optional)
7 Process and ambient temperature, process pressure
8 Material wetted parts
9 Order number
10 Serial number of the instrument
11 Symbol of the device protection class
12 ID numbers, instrument documentation
13 Reminder to observe the instrument documentation
14 NotiedauthorityforCEmarking
15 Approval directives
The type label contains the serial number of the instrument. With it
youcanndthefollowinginstrumentdataonourhomepage:
• Product code (HTML)
• Delivery date (HTML)
• Order-specicinstrumentfeatures(HTML)
• Operating instructions and quick setup guide at the time of ship-
ment (PDF)
• Order-specicsensordataforanelectronicsexchange(XML)
• Testcerticate(PDF)-optional
Go to "www.vega.com", "Search". Enter the serial number.
Alternatively, you can access the data via your smartphone:
• Download the VEGA Tools app from the "Apple App Store" or the
"Google Play Store"
• Scan the Data Matrix code on the type label of the instrument or
Type label
Serial number - Instru-
ment search

9
3 Product description
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
• Enter the serial number manually in the app
This operating instructions manual applies to the following instrument
versions:
• Hardware from 1.0.0
• Software from 1.3.0
• OnlyforinstrumentversionswithoutSILqualication
Theinstrumentcanbesuppliedintwodierentelectronicsversions.
Eachelectronicsversioncanbeidentiedviatheproductcodeonthe
type label as well as on the electronics.
• Standard electronics with operating voltage 90 … 253 V AC;
50/60Hz:TypFX80B.-
• Standard electronics with supply voltage 9.6 … 48 V DC;
20 … 42 V AC:Type FX80I.-
The scope of delivery encompasses:
• Sensor
• Optional accessory
• Optionally integrated Bluetooth module
• Documentation
– Quick setup guide VEGAFLEX 81
– Instructions for optional instrument features
– Ex-specic"Safety instructions" (with Ex versions)
– Ifnecessary,furthercerticates
Information:
In this operating instructions manual, the optional instrument features
are described.The respective scope of delivery results from the order
specication.
3.2 Principle of operation
The VEGAFLEX 81 is a level sensor with coax probe for continuous
level or interface measurement, suitable for applications in liquids.
High frequency microwave pulses are guided along a steel cable or
a rod. Upon reaching the product surface, the microwave pulses are
reected.Therunningtimeisevaluatedbytheinstrumentandoutput
as level.
Scope of this operating
instructions
Versions
Scope of delivery
Application area
Functional principle -
level measurement

10
3 Product description
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
d
h
1
Fig. 2: Level measurement
1 Sensorreferenceplane(sealsurfaceoftheprocesstting)
d Distance to the level
h Height - Level
High frequency microwave impulses are guided along a steel cable or
rod. Upon reaching the product surface, a part of the microwave im-
pulsesisreected.Theotherpartpassesthroughtheupperproduct
andisreectedbytheinterface.Therunningtimestothetwoproduct
layers are processed by the instrument.
TS
d1
h1
h2
d2
1
L2
L1
L3
Fig. 3: Interface measurement
1 Sensorreferenceplane(sealsurfaceoftheprocesstting)
d1 Distance to the interface
d2 Distance to the level
TS Thickness of the upper medium (d1 - d2)
h1 Height - Interface
h2 Height - Level
L1 Lower medium
L2 Upper medium
L3 Gas phase
Functional principle - in-
terface measurement

11
3 Product description
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
Upper medium (L2)
• The upper medium must not be conductive
• The dielectric constant of the upper medium or the actual distance
to the interface must be known (input required). Min. dielectric con-
stant:1.6.Youcanndalistofdielectricconstantsonourhome
page: www.vega.com.
• The composition of the upper medium must be stable, no varying
products or mixtures
• Theuppermediummustbehomogeneous,nostratications
within the medium
• Min. thickness of the upper medium 50 mm (1.97 in)
• Clear separation from the lower medium, emulsion phase or detri-
tus layer max. 50 mm (1.97 in)
• If possible, no foam on the surface
Lower medium (L1)
• The dielectric constant must be 10 higher than the dielectric
constant of the upper medium, preferably electrically conductive.
Example: upper medium dielectric constant 2, lower medium at
least dielectric constant 12.
Gas phase (L3)
• Air or gas mixture
• Gas phase - dependent on the application, gas phase does not
always exist (d2 = 0)
The instrument is always preset to the application "Level measure-
ment".
For the interface measurement, you can select the requested output
signal with the setup.
3.3 Packaging, transport and storage
Your instrument was protected by packaging during transport. Its
capacity to handle normal loads during transport is assured by a test
based on ISO 4180.
The packaging of standard instruments consists of environment-
friendly, recyclable cardboard. For special versions, PE foam or PE
foil is also used. Dispose of the packaging material via specialised
recycling companies.
Transport must be carried out in due consideration of the notes on the
transport packaging. Nonobservance of these instructions can cause
damage to the device.
The delivery must be checked for completeness and possible transit
damage immediately at receipt. Ascertained transit damage or con-
cealed defects must be appropriately dealt with.
Up to the time of installation, the packages must be left closed and
stored according to the orientation and storage markings on the
outside.
Prerequisites for inter-
face measurement
Output signal
Packaging
Transport
Transport inspection
Storage

12
3 Product description
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
Unless otherwise indicated, the packages must be stored only under
the following conditions:
• Not in the open
• Dry and dust free
• Not exposed to corrosive media
• Protected against solar radiation
• Avoiding mechanical shock and vibration
• Storage and transport temperature see chapter "Supplement -
Technical data - Ambient conditions"
• Relative humidity 20 … 85 %
With instrument weights of more than 18 kg (39.68 lbs) suitable and
approved equipment must be used for lifting and carrying.
3.4 Accessories and replacement parts
The display and adjustment module PLICSCOM is used for measured
value indication, adjustment and diagnosis. It can be inserted into the
sensor or the external display and adjustment unit and removed at
any time.
The integrated Bluetooth module (optional) enables wireless adjust-
ment via standard adjustment devices:
• Smartphone/tablet (iOS or Android operating system)
• PC/notebook with Bluetooth USB adapter (Windows operating
system)
Youcanndfurtherinformationintheoperatinginstructions"Display
andadjustmentmodulePLICSCOM" (Document-ID 36433).
The interface adapter VEGACONNECT enables the connection of
communication-capable instruments to the USB interface of a PC. For
parameter adjustment of these instruments, the adjustment software
PACTware with VEGA-DTM is required.
Youcanndfurtherinformationintheoperatinginstructions"Interface
adapterVEGACONNECT" (Document-ID 32628).
The VEGADIS 81 is an external display and adjustment unit for VEGA
plics®sensors.
For sensors with double chamber housing the interface adapter
"VEGADISadapter" is also required for VEGADIS 81.
Youcanndfurtherinformationintheoperatinginstructions
"VEGADIS81" (Document-ID 43814).
The VEGADIS adapter is an accessory part for sensors with double
chamber housings. It enables the connection of VEGADIS 81 to the
sensor housing via an M12 x 1 plug.
Youcanndfurtherinformationinthesupplementaryinstructions
"VEGADISadapter" (Document-ID 45250).
Storage and transport
temperature
Lifting and carrying
PLICSCOM
VEGACONNECT
VEGADIS 81
VEGADIS adapter

13
3 Product description
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
VEGADIS 82 is suitable for measured value indication and adjustment
of sensors with HART protocol. It is looped into the 4 … 20 mA/HART
signal cable.
Youcanndfurtherinformationintheoperatinginstructions
"VEGADIS824…20mA/HART" (Document-ID 45300).
PLICSMOBILE T81 is an external GSM/GPRS/UMTS radio unit for
transmission of measured values and for remote parameter adjust-
ment of HART sensors.The adjustment is carried out via a PC with
PACTware and the corresponding DTM or via smartphone/tablet with
the VEGA Tools app.The connection is made via the Bluetooth inter-
face integrated in PLICSMOBILE.
Youcanndfurtherinformationintheoperatinginstructions
"PLICSMOBILET81/B81/S81" (Document-ID 55234).
The protective cover protects the sensor housing against soiling and
intense heat from solar radiation.
Youwillndadditionalinformationinthesupplementaryinstructions
manual "Protective cover" (Document-ID 34296).
Screwedangesareavailableindierentversionsaccordingtothe
following standards: DIN 2501, EN 1092-1, BS 10, ASME B 16.5,
JIS B 2210-1984, GOST 12821-80.
Youcanndadditionalinformationinthesupplementaryinstructions
manual "FlangesaccordingtoDIN-EN-ASME-JIS".
The electronics module VEGAFLEX series 80 is a replacement part
forTDRsensorsofVEGAFLEXseries80.Thereisadierentversion
available for each type of signal output.
Youcanndfurtherinformationintheoperatinginstructionsmanual
"ElectronicsmoduleVEGAFLEXseries80".
The display and adjustment module can be optionally replaced by a
display and adjustment module with heating function.
You can use this display and adjustment module in an ambient tem-
perature range of -40 … +70 °C.
Youcanndfurtherinformationintheoperatinginstructions"Display
and adjustment module with heating" (Document-ID 31708).
If the standard sensor housing is too big or in case of strong vibra-
tions, an external housing can be used.
Then the sensor housing is made of stainless steel. The electronics is
located in the external housing which can be mounted in a distance of
up to 10 m (147 ft) to the sensor by using a connection cable.
Youcanndadditionalinformationintheoperatinginstructions
manual "Externalhousing" (Document-ID 46802).
VEGADIS 82
PLICSMOBILE T81
Protective cover
Flanges
Electronics module
Display and adjustment
module with heating
External housing

14
4 Mounting
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
4 Mounting
4.1 General instructions
Ondeviceswithathreadedtting,thehexagonontheprocesstting
must be tightened with a suitable wrench.
See chapter "Dimensions"forwrenchsize.
Warning:
The housing or the electrical connection may not be used for screw-
ing in! Tightening can cause damage, e. g. to the rotation mechanism
of the housing.
Protect your instrument against moisture ingress through the following
measures:
• Use a suitable connection cable (see chapter "Connectingto
power supply")
• Tighten the cable gland or plug connector
• Whenmountinghorizontally,turnthehousingsothatthecable
gland or plug connector point downward
• Lead the connection cable downward in front of the cable entry or
plug connector.
This applies mainly to outdoor installations, in areas where high
humidity is expected (e.g. through cleaning processes) and on cooled
or heated vessels.
To maintain the housing protection, make sure that the housing lid is
closed during operation and locked, if necessary.
Makesurethatthedegreeofcontaminationspeciedinchapter
"Technical data" meets the existing ambient conditions.
Metric threads
In the case of instrument housings with metric thread, the cable
glands are screwed in at the factory. They are sealed with plastic
plugs as transport protection.
You have to remove these plugs before electrical connection.
NPT thread
In the case of instrument housings with self-sealing NPT threads, it is
not possible to have the cable entries screwed in at the factory. The
free openings for the cable glands are therefore covered with red dust
protection caps as transport protection.The dust protection caps do
notprovidesucientprotectionagainstmoisture.
Prior to setup you have to replace these protective caps with ap-
proved cable glands or close the openings with suitable blind plugs.
Make sure before mounting that all parts of the instrument exposed to
the process are suitable for the existing process conditions.
These are mainly:
• Active measuring component
• Processtting
• Process seal
Screwing in
Protection against mois-
ture
Cable glands
Suitability for the process
conditions

15
4 Mounting
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
Process conditions in particular are:
• Process pressure
• Process temperature
• Chemical properties of the medium
• Abrasionandmechanicalinuences
Youcannddetailedinformationontheprocessconditionsinchapter
"Technical data" as well as on the type label.
The instrument is suitable for standard and extended ambient condi-
tions acc. to IEC/EN 61010-1.
4.2 Mounting instructions
In vessels with conical bottom it can be advantageous to mount the
sensor in the center of the vessel, as measurement is then possible
nearly down to the lowest point of the bottom. Keep in mind that
measurement all the way down to the tip of the probe may not be pos-
sible.The exact value of the min. distance (lower dead band) is stated
in chapter "Technical data".
Fig. 4: Vessel with conical bottom
Before beginning the welding work, remove the electronics module
from the sensor. By doing this, you avoid damage to the electronics
through inductive coupling.
Donotmounttheinstrumentsinorabovethellingstream.Makesure
thatyoudetecttheproductsurface,nottheinowingproduct.
Suitability for the ambient
conditions
Installation position
Welding work
Inowingmedium

16
4 Mounting
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
Fig.5:Mountingofthesensorwithinowingmedium
The reference plane for the measuring range of the sensors is the
sealingsurfaceofthethreadorange.
Keep in mind that a min. distance must be maintained below the refer-
ence plane and possibly also at the end of the probe - measurement
in these areas is not possible (dead band).These dead bands are
listed in chapter "Technical data". Keep in mind for the adjustment that
the default setting for the measuring range refers to water.
Theprocessttingmustbesealedifthereisgaugeorlowpressurein
the vessel. Before use, check if the seal material is resistant against
the measured product and the process temperature.
Themax.permissiblepressureisspeciedinchapter"Technical
data" or on the type label of the sensor.
If there is a risk of the coaxial probe touching the vessel wall during
operation due to product movements or agitators, etc., the measuring
probeshouldbesecurelyxed.
Avoidundenedvesselconnections,i.e.theconnectionmustbe
eithergroundedreliablyorisolatedreliably.Anyundenedchangeof
this condition can lead to measurement errors.
If there is a danger of the coaxial probe touching the vessel wall, then
the probe must be fastened at the bottom end.
Keep in mind that measurement is not possible below the fastening
point.
Measuring range
Pressure
Fasten

17
4 Mounting
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
1
2
1
2
Fig. 6: Fasten the probe
1 Coaxprobe
2 Retaining sleeve

18
5 Connecting to power supply
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
5 Connecting to power supply
5.1 Preparing the connection
Always keep in mind the following safety instructions:
Warning:
Connect only in the complete absence of line voltage.
• The electrical connection must only be carried out by trained,
qualiedpersonnelauthorisedbytheplantoperator.
• If overvoltage surges are expected, overvoltage arresters should
be installed.
Note:
Install a disconnecting device for the instrument which is easy to
access.The disconnecting device must be marked for the instrument
(IEC/EN 61010).
In this case, the instrument is designed in protection class I. To main-
tain this protection class, it is absolutely necessary that the ground
conductor be connected to the internal ground terminal.Take note of
the national installation regulations.
Supply voltage and current signal are carried on separate connection
cables if reliable separation is required.The supply voltage range can
dierdependingontheinstrumentversion.
Thedataforpowersupplyarespeciedinchapter"Technical data".
In this case, the instrument is designed in protection class II. Gener-
allyconnecttheinstrumenttovesselground(potentialequalization)
or with plastic vessels to the next ground potential. For this purpose, a
ground terminal is located laterally on the instrument housing.
An approved, three-wire installation cable with PE conductor is
required for voltage supply with mains voltage.
The 4 … 20 mA current output is connected with standard two-wire
cable without screen. If electromagnetic interference is expected
which is above the test values of EN 61326-1 for industrial areas,
screened cable should be used.
Make sure that the cable used has the required temperature resist-
anceandresafetyformax.occurringambienttemperature
Use cable with round cross section for instruments with housing and
cable gland. Use a cable gland suitable for the cable diameter to
ensurethesealeectofthecablegland(IPprotectionrating).
Metric threads
In the case of instrument housings with metric thread, the cable
glands are screwed in at the factory. They are sealed with plastic
plugs as transport protection.
You have to remove these plugs before electrical connection.
Safety instructions
Voltage supply via mains
voltage
Voltage supply via low
voltage
Connection cable
Cable glands

19
5 Connecting to power supply
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
NPT thread
In the case of instrument housings with self-sealing NPT threads, it is
not possible to have the cable entries screwed in at the factory. The
free openings for the cable glands are therefore covered with red dust
protection caps as transport protection.
Prior to setup you have to replace these protective caps with ap-
proved cable glands or close the openings with suitable blind plugs.
On plastic housings, the NPT cable gland or the Conduit steel tube
must be screwed into the threaded insert without grease.
Max. torque for all housings, see chapter "Technical data".
If screened cable is required, we recommend connecting the cable
screening on both ends to ground potential. In the sensor, the cable
screening must be connected directly to the internal ground terminal.
The ground terminal on the outside of the housing must be connected
to the ground potential (low impedance).
In Ex systems, the grounding is carried out according to the installa-
tion regulations.
In electroplating plants as well as plants for cathodic corrosion protec-
tionitmustbetakenintoaccountthatsignicantpotentialdierences
exist. This can lead to unacceptably high currents in the cable screen
if it is grounded at both ends.
Information:
Themetallicpartsoftheinstrument(processtting,sensor,concen-
tric tube, etc.) are connected with the internal and external ground
terminal on the housing.This connection exists either directly via
the conductive metallic parts or, in case of instruments with external
electronics, via the screen of the special connection cable.
Youcanndspecicationsonthepotentialconnectionsinsidethe
instrument in chapter "Technical data".
5.2 Connecting
The voltage supply and signal output are connected via the spring-
loaded terminals in the housing.
Connection to the display and adjustment module or to the interface
adapter is carried out via contact pins in the housing.
Information:
The terminal block is pluggable and can be removed from the
electronics. To do this, lift the terminal block with a small screwdriver
and pull it out. When reinserting the terminal block, you should hear it
snap in.
Proceed as follows:
1. Unscrew the housing lid
2. Loosen compression nut of the cable gland and remove blind
plug
Cable screening and
grounding
Connection technology
Connection procedure

20
5 Connecting to power supply
VEGAFLEX 81 • Four-wire 4 … 20 mA/HART
42280-EN-190131
3. Remove approx. 10 cm (4 in) of the cable mantle (signal output),
strip approx. 1 cm (0.4 in) insulation from the ends of the indi-
vidual wires
4. Insert the cable into the sensor through the cable entry
Fig.7:Connectionsteps5and6
5. Insert the wire ends into the terminals according to the wiring plan
Information:
Solidcoresaswellasexiblecoreswithwireendsleevesareinsert-
eddirectlyintotheterminalopenings.Incaseofexiblecoreswithout
end sleeves, press the terminal from above with a small screwdriver,
the terminal opening is then free. When the screwdriver is released,
the terminal closes again.
6. Check the hold of the wires in the terminals by lightly pulling on
them
7. Connect the cable screening to the internal ground terminal, con-
nect the outer ground terminal to potential equalisation in case of
power supply via low voltage
8. Connect the lead cable for voltage supply in the same way ac-
cording to the wiring plan, in addition connect the ground conduc-
tor to the inner ground terminal when powered with mains voltage.
9. Tighten the compression nut of the cable glands.The seal ring
must completely encircle the cables
10. Screw the housing lid back on
Theelectricalconnectionisnished.
Information:
The terminal blocks are pluggable and can be removed from the
housing insert. To do this, lift the terminal block with a small screwdriv-
er and pull it out. When inserting the terminal block again, you should
hear it snap in.