Vega VEGAFLEX 81 User manual

Operating Instructions
TDR sensor for continuous level and
interface measurement of liquids
VEGAFLEX 81
Two-wire 4 … 20 mA/HART
Coax probe
Document ID: 42279

2
Contents
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
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................................................................................................................... 5
2.6 NAMUR recommendations .............................................................................................. 6
2.7 Installation and operation in the USA and Canada ........................................................... 6
2.8 Environmental instructions ............................................................................................... 6
3 Product description ................................................................................................................. 7
3.1 Conguration.................................................................................................................... 7
3.2 Principle of operation........................................................................................................ 9
3.3 Packaging, transport and storage................................................................................... 11
3.4 Accessories.................................................................................................................... 11
4 Mounting................................................................................................................................. 13
4.1 General instructions ....................................................................................................... 13
4.2 Mounting instructions ..................................................................................................... 14
5 Connecting to power supply................................................................................................. 17
5.1 Preparing the connection ............................................................................................... 17
5.2 Connecting..................................................................................................................... 18
5.3 Wiring plan, single chamber housing.............................................................................. 19
5.4 Wiring plan, double chamber housing ............................................................................ 20
5.5 Wiring plan, Ex-d-ia double chamber housing................................................................ 22
5.6 Double chamber housing with VEGADIS-Adapter.......................................................... 23
5.7 Wiring plan - version IP66/IP68, 1 bar ............................................................................ 24
5.8 Supplementary electronics............................................................................................. 24
5.9 Switch-on phase............................................................................................................. 24
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................................................................................... 45
7 Setup with PACTware............................................................................................................. 47
7.1 Connect the PC.............................................................................................................. 47
7.2 Parameter adjustment with PACTware............................................................................ 47
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

3
Contents
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
9 Diagnostics and servicing .................................................................................................... 52
9.1 Maintenance .................................................................................................................. 52
9.2 Diagnosis memory ......................................................................................................... 52
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 .................................................................................................................... 72
11.3 Industrial property rights................................................................................................. 77
11.4 Trademark ...................................................................................................................... 77
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: 2021-08-19

4
1 About this document
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
1 About this document
1.1 Function
This instruction provides all the information you need for mounting,
connection and setup as well as important instructions for mainte-
nance,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, note, tip: This symbol indicates helpful additional infor-
mation and tips for successful work.
Note: This symbol indicates notes to prevent failures, malfunctions,
damage to devices or plants.
Caution: Non-observance of the information marked with this symbol
may result in personal injury.
Warning: Non-observance of the information marked with this symbol
may result in serious or fatal personal injury.
Danger: Non-observance of the information marked with this symbol
results in serious or fatal personal injury.
Ex applications
This symbol indicates special instructions for Ex applications.
• List
The dot set in front indicates a list with no implied sequence.
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 • Two-wire 4 … 20 mA/HART
42279-EN-210914
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.
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.
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.
The EU conformity declaration can be found on our homepage.

6
2 For your safety
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
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
A Class 2 power supply unit has to be used for the installation in the
USA and Canada.
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"
• Chapter "Disposal"

7
3 Product description
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
3 Product description
3.1 Conguration
The scope of delivery encompasses:
• Sensor VEGAFLEX 81
• Optional accessory
• Optionally integrated Bluetooth module
The further scope of delivery encompasses:
• 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:
Optional instrument features are also described in this operating
instructions manual.The respective scope of delivery results from the
orderspecication.
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typelabelcontainsthemostimportantdataforidenticationand
use of the instrument:
Scope of delivery
Scope of this operating
instructions
Type label

8
3 Product description
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
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
Move to "www.vega.com"andenterinthesearcheldtheserial
number of your instrument.
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 QR-code on the type label of the device or
• Enter the serial number manually in the app
Serial number - Instru-
ment search

9
3 Product description
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
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 medium surface, the microwave pulses are
reected.Therunningtimeisevaluatedbytheinstrumentandoutput
as level.
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 medium 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.
Application area
Functional principle -
level measurement
Functional principle - in-
terface measurement

10
3 Product description
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
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
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)
Prerequisites for inter-
face measurement

11
3 Product description
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
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 consists of environment-friendly, recyclable card-
board. 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.
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
The instructions for the listed accessories can be found in the down-
load area on our homepage.
The display and adjustment module is used for measured value indi-
cation, adjustment and diagnosis.
The integrated Bluetooth module (optional) enables wireless adjust-
ment via standard adjustment devices.
The interface adapter VEGACONNECT enables the connection of
communication-capable instruments to the USB interface of a PC.
Output signal
Packaging
Transport
Transport inspection
Storage
Storage and transport
temperature
Lifting and carrying
PLICSCOM
VEGACONNECT

12
3 Product description
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
The VEGADIS 81 is an external display and adjustment unit for VEGA
plics®sensors.
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.
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.
PLICSMOBILE 81 is an internal GSM/GPRS/UMTS radio unit for
HART sensors for transmitting measured values and for remote
parameterization.
The 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 protective cover protects the sensor housing against soiling and
intense heat from solar radiation.
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.
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.
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 15 m (49.2 ft) to the sensor by using a connection cable.
VEGADIS 81
VEGADIS adapter
VEGADIS 82
PLICSMOBILE 81
PLICSMOBILE T81
Protective cover
Flanges
Display and adjustment
module with heating
External housing

13
4 Mounting
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
4 Mounting
4.1 General instructions
Deviceswiththreadedttingarescrewedintotheprocessttingwith
a suitable wrench via the hexagon.
See chapter "Dimensions"forwrenchsize.
Warning:
The housing or the electrical connection may not be used for screw-
ing in! Depending on the device version, tightening can cause dam-
age, 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
• 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.
Note:
Make sure that during installation or maintenance no moisture or dirt
can get inside the instrument.
To maintain the housing protection, make sure that the housing lid is
closed during operation and locked, if necessary.
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.
Note:
For safety reasons, the instrument must only be operated within the
permissibleprocessconditions.Youcannddetailedinformationon
the process conditions in chapter "Technical data" of the operating
instructions or on the type label.
Screwing in
Protection against mois-
ture
Cable glands
Process conditions

14
4 Mounting
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
Hence make sure before mounting that all parts of the instrument ex-
posed to the process are suitable for the existing process conditions.
These are mainly:
• Active measuring component
• Processtting
• Process seal
Process conditions in particular are:
• Process pressure
• Process temperature
• Chemical properties of the medium
• Abrasionandmechanicalinuences
4.2 Mounting instructions
In vessels with conical bottom it can be advantageous to mount the
device 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 blocking distance) 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mediumsurface,nottheinowingproduct.
Installation position
Welding work
Inowingmedium

15
4 Mounting
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
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 (blocking distance).These blocking
distances 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 sealing 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

16
4 Mounting
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
1
2
1
2
Fig. 6: Fasten the probe
1 Coaxprobe
2 Retaining sleeve

17
5 Connecting to power supply
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
5 Connecting to power supply
5.1 Preparing the connection
Always keep in mind the following safety instructions:
• Carryoutelectricalconnectionbytrained,qualiedpersonnel
authorised by the plant operator
• If overvoltage surges are expected, overvoltage arresters should
be installed
Warning:
Onlyconnectordisconnectinde-energizedstate.
Power supply and current signal are carried on the same two-wire
cable.Theoperatingvoltagecandierdependingontheinstrument
version.
Thedataforpowersupplyarespeciedinchapter"Technical data".
Provide a reliable separation between the supply circuit and the
mains circuits according to DIN EN 61140 VDE 0140-1.
Power the instrument via an energy-limited circuit acc. to IEC 61010-
1, e.g. via Class 2 power supply unit.
Keepinmindthefollowingadditionalfactorsthatinuencetheoperat-
ing voltage:
• Lower output voltage of the power supply unit under nominal load
(e.g. with a sensor current of 20.5 mA or 22 mA in case of fault
signal)
• Inuenceofadditionalinstrumentsinthecircuit(seeloadvaluesin
chapter "Technical data")
The instrument is connected with standard two-wire cable without
shielding. If electromagnetic interference is expected which is above
the test values of EN 61326-1 for industrial areas, shielded cable
should be used.
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).
We generally recommend the use of shielded cable for HART
multidrop mode.
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.
Note:
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
Safety instructions
Voltage supply
Connection cable
Cable glands

18
5 Connecting to power supply
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
free openings for the cable glands are therefore covered with red dust
protection caps as transport protection.
Note:
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 shielded 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.
Note:
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. If a display and adjustment module is installed, remove it by turn-
ing it slightly to the left
3. Loosen compression nut of the cable gland and remove blind
plug
Cable screening and
grounding
Connection technology
Connection procedure

19
5 Connecting to power supply
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
4. Remove approx. 10 cm (4 in) of the cable mantle, strip approx.
1 cm (0.4 in) of insulation from the ends of the individual wires
5. Insert the cable into the sensor through the cable entry
1 2
Fig.7:Connectionsteps5and6
1 Single chamber housing
2 Double chamber housing
6. Insert the wire ends into the terminals according to the wiring plan
Note:
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.
7. Check the hold of the wires in the terminals by lightly pulling on
them
8. Connect the shielding to the internal ground terminal, connect the
external ground terminal to potential equalisation
9. Tighten the compression nut of the cable entry gland. The seal
ring must completely encircle the cable
10. Reinsert the display and adjustment module, if one was installed
11. Screw the housing lid back on
Theelectricalconnectionisnished.
5.3 Wiring plan, single chamber housing
The following illustration applies to the non-Ex, Ex-ia and Ex-d ver-
sion.

20
5 Connecting to power supply
VEGAFLEX 81 • Two-wire 4 … 20 mA/HART
42279-EN-210914
5
12
+
( ) (-)
678
4...20mA
2
3
4
1
Fig.8:Electronicsandconnectioncompartment-singlechamberhousing
1 Voltage supply, signal output
2 For display and adjustment module or interface adapter
3 For external display and adjustment unit
4 Ground terminal for connection of the cable screening
5.4 Wiring plan, double chamber housing
The following illustration applies to the non-Ex, Ex-ia and Ex-d ver-
sion.
5678
4...20mA
12
+
( ) (-)
2
1 1
Fig.9:Electronicscompartment-doublechamberhousing
1 Internal connection to the connection compartment
2 For display and adjustment module or interface adapter
Electronics and connec-
tion compartment
Electronics compartment