Page 1
VEGATROL 10 Ex 1
VEGATOR 526W Ex
on
TIB • Technical Information • Operating Instructions
Fail safe overfill
protection for
pressurized vessels
storing liquid gas
Approved acc. to the
VdTÜV-information
"Overfill protection" 100
no. TÜV.ÜS.94-32
liquid gas PN 25
Corresponds to the
requirements to
component tested overfill
protections of TRB 801,
no. 25
Corresponds to the
requirements of
DIN V 19250 AK 5
Conformity certificates
PTB-no. Ex-93.C.4015
BVS-no. 93.C.2015 X
VEGA Grieshaber KG
Postfach 11 42
D-77757 Schiltach
Phone 0 78 36 / 50 - 0
Fax 0 78 36 / 50 201
Page 2
Contents
1 Introduction
1.1 Contents of the instruction manual .....................................................................................................................3
1.2 Safety information ...............................................................................................................................................3
1.3 Approvals ............................................................................................................................................................3
2 Technical Information
2.1 Product description .............................................................................................................................................4
2.2 Configuration of an overfill protection..................................................................................................................5
2.3 Technical data .....................................................................................................................................................6
2.3.1 Signal conditioning instrument VEGA TOR 526 W Ex ..............................................................................6
2.3.2 Sensor VEGASWING 83 W5 Ex with oscillator E86 Ex...........................................................................8
2.4 Dimensional drawings ......................................................................................................................................... 8
2.4.1 VEGASWING 83 W5 Ex .......................................................................................................................... 8
2.4.2 Flanges .................................................................................................................................................... 9
2.4.3 Signal conditioning instrument VEGA TOR 526 W Ex ..............................................................................9
2.5 Electrical connection ......................................................................................................................................... 10
2.5.1 Signal conditioning instrument VEGA TOR 526 W Ex ............................................................................10
2.5.2 Connection examples for overvoltage arresters.....................................................................................11
2.6 Mounting instructions and regulations .............................................................................................................. 12
Contents
3 Mounting and set-up
3.1 Mounting ........................................................................................................................................................... 13
3.2 Set-up................................................................................................................................................................13
3.3 Operation .......................................................................................................................................................... 14
4 Supplement
4.1 Fault signals ......................................................................................................................................................14
4.2 Calculation information for sensor length..........................................................................................................15
4.3 General instructions for the use of overfill protection ........................................................................................16
2
VEGATROL 10 Ex 1
Page 3
1 Introduction
1 Introduction
1.1 Contents of the instruction manual
This Technical Information / Operating Instructions
(T.I.B.) contains information for correct
- installation
- connection
- set-up
for the fail-safe-protection VEGATROL 10 Ex 1.
This TIB is supplied as part of the order. Knowledge of the
contents is important for correct operation of the
instrument. This TIB accompanies the product and is
addressed to technical staff which is trained or has
knowledge of the use of level measurement and control
equipment.
1.2 Safety information
The instrument must only be operated as described in this
TIB. Please note that other action can cause damage for
which VEGA does not take liability.
1.3 Approvals
Ex-Zone 1
The system sensor VEGATROL 10 is approved for the use
in hazardous areas zone 1. In such cases the regulations
and special conditions of the conformity certificate PTB-no.
Ex-93.C.4015 and BVS-no. 93.C.2015 X must be
observed.
VdTÜV
VEGATROL 10 is approved acc. to VdTÜV-information
"Overfill protection" 100 as overfill protection in stationary
storage vessels in liquid gas plants of groups A, B, C and
D (approval no. TÜV.ÜS.94-32).
This approval is also valid for storage vessels in
distribution plants.
DIN
The overfill protection of VEGATROL 10 corresponds to
the requirements of DIN V 19250, class 5.
TRB
VEGATROL 10 corresponds to the requirements on
component tested overfill protections acc. to TRB 801,
no. 25.
Overfill protection in vessels up from group C
Also in case where TRB 801, no. 25, item 6.1.4.2 requires
two independent overfill protections, one VEGATROL 10
is sufficient to meet with this requirement.
VEGATROL 10 Ex 1
3
Page 4
2 Technical Information
2 T echnical Information
2.1 Product description
General
The described fail-safe overfill protection VEGA TROL 10
consists of a VEGASWING 83 W5 Ex vibrating level switch
and VEGA TOR 526 W Ex signal conditioning instrument.
The application range comprises stationary vessels acc. to
the pressure vessel regulations for storing liquid gas acc.
to DIN 51 622:
- in individual vessel plants
- in liquid gas plants
- in distribution plants
- in plants with several vessels
each of group A, B, C and D.
When used in distribution plants up from group C min.
separate overfill protections must be installed acc. to the
requirement of TRB 801, no. 25. Even in these cases
VEGATROL 10 is sufficient due to the VdTÜV-approval to
meet with the TRB-requirement.
In plants with several vessels VEGA TROL 10 can be used
as continuous monitoring and locking system.
Function
The level is detected by a vibrating level switch
VEGASWING. Its tuning fork is piezoelectrically energized
and vibrates at its mechanical resonance frequency. A
second piezoelectric element measures this resonance
frequency. If the tuning fork is covered by the liquid gas,
the resonance frequency changes proportional to the
degree of covering. The oscillator in VEGASWING detects
continuously the resonance frequency and converts the
value into a current to the signal conditioning instrument.
When the switch point is reached an erratic increase of the
current signal is triggered. The level relay in the signal
conditioning instrument de-energizes.
two
one
Fail-safe / Self-monitoring
A special feature of the overfill protection of VEGATROL
10 is the integral self-monitoring. It is based on a redundant microprocessor system in the signal conditioning
instrument and includes the whole measuring chain from
the tuning fork via the oscillator, the two-wire line as well
as the signal conditioning instrument.
The self-monitoring includes two routines:
- the permanent monitoring
- the cyclical selftest.
During the permanent monitoring the signal conditioning
instrument causes the oscillator of the sensor to trigger a
test cycle in 960 msec. cycle. Defined test signals are
transmitted via the two-wire line to the signal conditioning
instrument. Possible failures in the sensor electronics as
well as line break, short-circuit and mechanical damage on
the tuning fork are signalled via these test signals. During
the cyclical selftest security relevant components and
procedures (e.g. level relay, CPU, memory, time reaction)
are checked in the signal conditioning instrument in a very
tough time pattern. The function test of the level relays is
made without interruption of the circuit of connected
systems.
If during the self-monitoring a failure is detected, the level
relays and the fail safe relay de-energize.
Due to the above mentioned measures a reliable and
correct function of the overfill protection is ensured without
any staff involved for control tasks.
4
VEGATROL 10 Ex 1
Page 5
2 Technical Information
2.2 Configuration of an overfill protection
Storage vessels in liquid gas plants of group A, B, C and D
The overfill protection VEGATROL 10 for a storage vessel consists of:
- VEGASWING 83 W5 Ex level switch with integral oscillator E86 Ex
- VEGATOR 526 W Ex signal conditioning instrument
Additional instruments:
- continuous level measuring system
- overvoltage arresters etc. acc. to the requirements of the system.
Version I: cylindrical tank
VEGASWING
Ex-Zone 1
Version II: spherical tank
VEGASWING
Ex-Zone 1
two-wire line
(intrinscially safe
circuit)
two-wire line
(intrinsically safe
VEGATOR 526 W Ex
VEGATOR 526 W Ex
on
!
circuit)
Not Ex-area
Overifll
protection
VEGATOR 526 W Ex
VEGATOR 526 W Ex
on
!
Overfill
protection
VEGATROL 10 Ex 1
Not Ex-area
5
Page 6
2.3 Technical data
2.3.1 Signal conditioning instrument VEGAT OR 526 W Ex
Power supply
Operating voltage U
Power consumption approx. 11 VA or approx. 8 W
Fuse (internal) plug fuse 800 mA, moderately slow blow
Measuring data input - Operating data
Data transmission analog, 4 … 20 mA
Power supply 14 … 18,9 V DC
Current limitation bei 45 mA, short-circuit proof
Connection line 2-wire
Resistance per conductor max. 35 Ohm
Measuring data input - Ex-technical data
Max. values: voltage U ≤ 18,9 V DC
current I ≤ 95 mA
efficiency P ≤ 647 mW
Characteristics trapezoidal
Internal effective inductance L
Internal effective capacitance C
int
int
= 24 V AC (20 … 28 V), 50 / 60 Hz or
nenn
= 24 V DC (16 … 60 V)
unimportant
≤ 10 nF
2 T echnical Information
Flame proofing EEx … IIC EEx … IIB
Max. permissible outer inductance L
… ia… 0,5 mH 1 mH 1,5 mH 2 mH 0,5 mH 1 mH 1,5 mH 2 mH
ext
… ib… 4 mH 15 mH
Max. permissible outer capacitance C
… ia… 52 nF 40 nF 27 nF 15 nF 200 nF 190 nF 177 nF 160 nF
ext
… ib… 240 nF 1,1 F
The intrinsically safe circuit is reliably galvanically separated from the not-intrinsically safe circuits up to a peak value of
375 V of the nominal voltage.
Level relay
Contact 1 floating spdt, AgCdO and gold flashed
Min. turn-on voltage 12 V DC
switching current 10 mA DC
Max. turn-on voltage 250 V AC, 48 V DC
switching current 2,5 A at 250 V AC; 1 A at 48 V DC
breaking capacity 125 VA AC
Required external fuse
for relay contacts 2 A, slow
Fail safe relay
Contact 1 floating spdt, AgCdO and Au plated
Min. turn-on voltage 10 mV
switching current 10 µA
Max. turn-on voltage 250 V AC, 60 V DC
switching current 2 A AC, 1 A DC
breaking capacity 125 VA AC, 60 W DC
Ambient conditions
Permissible operating temperature -20°C … +70°C
Storage and transport temperature -25°C … +80°C
Electrical connection
Connection Plug connection acc. to DIN 41 612, series F, 32-pole, d, z
Carrier 596 Ex Connection to the respective module
Housing 589 - 10 Ex Connection to terminal (max. 1,5 mm
6
2
)
VEGATROL 10 Ex 1
Page 7
2 Technical Information
Electrical protective measures
Protection unassembled IP 00
installed in carrier type 596 Ex with Ex-module
front completely equipped .........................IP30
upper and lower side ................................IP20
wiring side rear ................................IP00
installed in housing type 589 - 10 Ex...........................IP30
(in both cases observe the respective TIB)
Protection class II (in housing 589)
Overvoltage category II
Mechanical data
Series Module unit for carrier type 596 Ex or
housing 589 - 10 Ex
Dimensions unassembled W = 50,8 mm (10 TE), H = 128,4 mm, D = 162 mm
Dimensions in plastic housing 589 W = 62,5 mm, H = 136 mm, D = 222 mm
Weight approx. 400 g
VEGATOR 526 W Ex must only be connected to instruments in which no higher voltages than AC 250 V (50 Hz) occur.
Potential stages and galvanic separation
Sensor
Ex-area
Meas. data input Power sup. unit
P1
Microcomputer control and output Relay contacts Relay contacts
P3 P4 P5
Fail safe relay Level relay
Voltage supply
P2
P1 … P5
Potential stages
VEGATROL 10 Ex 1
7
Page 8
2.3.2 Sensor VEGASWING 83 W5 Ex with oscillator E86 Ex
Supply and signal circuit
Power supply 12 … 18,9 V DC
(from signal conditioning instrument VEGAT OR 526 W Ex)
Data transmission analog, 4 … 20 mA
Flame proofing EEx ia IIC, T4
Internal effective capacitance C
Internal effective inductance L
Power consumption tuning fork uncovered approx. 7 mA
tuning fork coverd 10 … 20 mA
Fault signal approx. 25 mA
Reference value approx. 15 mA
Connection line 2-wire
Ambient conditions
Permissible operating temperature -30°C … +70°C
Storage and transport temperature -40°C … +80°C
Operating pressure max. 25 bar
unimportant
int
unimportant
int
however observe max. permissible pressure of the flange
2 T echnical Information
Electrical connection
Terminals in plastic housing for connection of max. 1,5 mm
Cable entry Pg 13,5
Electrical protective measures
Protection IP 67
Protection class II
Mechanical data
Material Mounting parts stainless steel 1.4571
Extension tube stainless steel 1.4571
Tuning fork stainless steel 1.4581
Resonance frequency of the tuning fork in air approx. 380 Hz
Dimensions see dimensional drawing
2.4 Dimensional drawings
2.4.1 VEGASWING 83 W5 Ex
(approx. dimensions in mm)
80x110
75
approx. 30
2
39
L (min. 200, max. 3000)
Switch point
25
8
VEGATROL 10 Ex 1
Page 9
2 Technical Information
2.4.2 Flanges
The welded flanges for VEGASWING 83 W5 Ex are made of stainless steel (material no. 1.4571) acc. to DIN 2527 or
ANSI - ASA - B 16,5.
Flange acc. to DIN (dimensions in mm)
90°
45°
Flange Dimensions Holes
DN PN D b k Number Screws d
50 25 / 40 165 20 125 4 M16 18
65 25 / 40 185 22 145 8 M16 18
80 25 / 40 200 24 160 8 M16 18
100 25 / 40 235 24 190 8 M20 22
150 25 / 40 300 28 250 8 M24 26
d
2
b
ø k
ø D
D = outer flange diameter
b = flange thickness
k = hole circle
d
= diameter of holes
2
Flange acc. to ANSI (dimensions in mm)
Flange Dimensions Holes
ANSI psi D b k Number Screws d
2" 600 165,1 25,4 127,0 8 M16 19,1
1
2
/2" 600 190,5 28,4 149,4 8 M20 22,4
3" 600 209,6 31,8 168,1 8 M20 22,4
4" 600 273,1 38,1 215,9 8 M24 25,4
2.4.3 Signal conditioning instrument VEGATOR 526 W Ex
(approx. dimensions in mm)
2
2
12
Circuit board 100 x 160 x 1,5 Multipoint connector
European size
100
162
4
10 TE
128,4
50,8
VEGATROL 10 Ex 1
9
Page 10
2.5 Electrical connection
2.5.1 Signal conditioning instrument VEGAT OR 526 W Ex
Coordination of the Terminal socket with multipoint Module with multipoint
terminal socket or the connector (part of the housing connector acc. to DIN
multipoint connector type 589 - 10 Ex) 41 612 for carrier
d b z
2 L1 (+)
N (-)
2
4
8
8
10
18
20
30
32
Power supply
Fail safe relay
Level relay
(overfill
protection)
+
Measuring
-
data input
(intrinsically
safe signal
circuit)
10
12
14
16
18
20
22
24
28
30
32
2 T echnical Information
(rear view)
10
12
14
16
18
20
22
24
28
30
32
z
2
4
6
8
Separation
d b z
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
z
d
2
4
6
8
Coded
key
E Ex i
d
Not Ex-area
Ex-area
Note:
- the relay contacts are shown in currentless condition
Sensor 1
2 3
1
Ex-separation
Overvoltage arrester
Connection when using
overvoltage arresters, see
page 11
Overvoltage arrester
Oscillator of VEGASWING
83 W5 Ex
10
VEGATROL 10 Ex 1
Page 11
2 Technical Information
2.5.2 Connection examples for overvoltage arresters Vessel without cathodic tank protection
Ex-area Not Ex-area
VEGASWING
E86 Ex
External earth terminal
Overvoltage arrester
Type B 62 - 27 Ex 0-2
or B 62 - 27 Ex-2
Overvoltage arrester
Outer isolation
1
2
Line length
A1
A2
≤ 50 m
Screen
min. 4 mm2 Cu
Metal housing isolated or
plastic housing
E1
Typ
B62-27
E2
Earth / PA
connection terminal
Outer isolation
Screen
either
overvoltage arrester
Typ
E1
B62-27G
A1
A2E2
d30
d32
VEGATOR
526 W Ex
Note:
- Suitable cable must be used, either with metal cover (or screen). If a
(control room)
to potential
equalization line
cable with metal cover or screen is used (as on above figure), a potential
equalization along the entire length of the intrinsically safe circuit is not
necessary. Screen or metal cover must only be connected to the
overvoltage arrester.
- The current load capacity of the screen must correspond at least to that
of a 1,5 mm
2
Cu-line.
Vessel with cathodic tank protection
Ex-area Not Ex-area
Overvoltage arrester
Type B 62 - 27 Ex 0 - 2
or B 62 - 27 Ex - 2
E86 Ex
External
earth terminal
VEGASWING
1
2
Cathodic tank protection
2 … 24 V
(object voltage)
Outer isolation
Line length
≤ 50 m
Screen
min. 4 mm
(control room)
Overvoltage arrester
A1
Typ
B62-27
A2
2
Cu
Metal housing isolated or
plastic housing
Outer isolation
E1
E2
Screen
Earth / PA
connection terminal
either
overvoltage arrester
Typ
E1
B62-27G
A1
A2E2
d30
d32
Note:
- Suitable cable must be used with metal cover (or screen). Screen or metal
cover must only be connected to the overvoltage arrester. Screen or
metal cover must not be earthed.
- The cable must have an outer isolation.
- The current load capacity of the screen must correspond at least to that
of a 1,5 mm
2
Cu-line.
VEGATOR
526 W Ex
VEGATROL 10 Ex 1
11
Page 12
2 T echnic Information
2.6 Mounting instructions and regulations
General instruction for electrical connection
The electrical connection is made acc. to the wiring diagram on page 12 and 13 or acc. to the type plates on the
instruments. The voltage stated on the type plate of the
signal conditioning instrument must correspond with the
value of the power supply.
Coding
A mechanical coding in form of a pin in the multipoint
connector and a hole in the multiple plug ensures that only
one Ex-instrument can be placed in one Ex-module
(carrier or housing).
In case of connection of a sensor installed in the Ex-area it
must be ensured that VEGATOR 526 W Ex (see figure) is
provided with a coded key in the respective position.
Ex-modules of Messrs. VEGA are supplied with plugged in
coded key .
2
4
6
8
10
12
14
16
18
20
Coded key here
22
24
26
28
30
32
- If strong electromagnetic interferences have to be
expected, screened cable is recommended.
- If there is a danger of overvoltages, overvoltage
arresters are recommended. Observe the respective
TIB for connection.
- Connected systems must correspond to VDE 0100 part
725 (auxiliary circuits).
- If screened cable is used, the screening should be
earthed at one end. The earth must be realized on the
sensor.
- The respectively valid Ex-regulations as well as the
special conditions in the conformity certificate must be
observed.
Ex-mounting regulations
The VEGA TOR 526 W Ex signal conditioning instrument
and the signal conditioning instrument for the capacitive
measuring electrode must be installed generally outside
hazardous areas (or special Ex-protective measures must
be taken).
Installation into carrier (DIN 41 494 part 5)
VEGATOR 526 W Ex must be installed such that a
protection of min. IP 20 (acc. to IEC 144 (529)) is reached.
This is ensured with carrier type 596 Ex. It must be
furthermore observed that a min. distance of 50 mm is
kept between intrinsically and not-intrinsically safe circuits.
This can be realized by adding a separation (included in
"VEGA-module"). The required air gaps and creeping
distances between the instruments in the carrier must be
maintained. Observe therefore EN 50 020, especially
schedule 2, modification 2. The following instructions are
valid with e.g. a voltage of 250 V AC, 50 Hz (corresponds
to a peak value of 375 V) in neighbouring instruments:
- Between the left carrier wall and VEGATOR 526 W Ex a
distance of 2 TE must be maintained.
- If a power supply unit VEGASTAB 592 or 593 is used,
observe the mounting instructions in the TIB of the
carrier.
- If VEGA TOR 526 W Ex is mounted together with notEx-instruments or instruments of other manufacturers in
a carrier, a min. distance of 2 TE must be maintained to
these instruments.
- This min. distance is not required if the VEGAinstrument (10 TE width) on the left of VEGATOR
526 W Ex is provided with a black cover on its right
side.
Coding on the multipoint connector
(view)
General mounting and installation regulations
- The wiring between signal conditioning instrument and
sensor can be made with standard cable suitable and
marked for intrinsically safe circuits.
- Line resistance, max. permissible outer inductance and
capacitance, see technical data page 6 to 8.
12
Installation into housing type 589 - 10 Ex
In case of installation of VEGA TOR 526 W Ex into housing
type 589 - 10 Ex the distances between intrinsically and
not intrinsically safe circuits must be maintained.
VEGATROL 10 Ex 1
Page 13
3 Mounting and set-up
3 Mounting and set-up
3.1 Mounting
The tuning fork of VEGASWING is marked, showing the
submersion depth up to the switch point. The marking
relates to liquid gas when the instrument is vertically
mounted (see 2.4 Dimensional drawings).
The switch point must be generally at 85 % of the vessel
volume.
The adaption to the respective vessel dimensions is
realized via dimensioning of the concentric tube.
Calculation help see supplement.
A sealing must be used between flange of VEGASWING
which is suitable for the use in liquid gas plants.
In case of installation lengths of VEGASWING exceeding
1,5 m the extension tube in the vessel must be protected
against bending (e.g. vibrations by fluctuating product). If
there is danger of mechanical damage, the extension tube
in the vessel must be protected against bending.
VEGASWING must be generally mounted vertically.
3.2 Set-up
Pre-requirements for set-up
- the sensor VEGATROL is installed in its final position
and the tuning fork is not covered
- the failure LED is dark
The set-up is carried out by pushing the set-up key for
approx. 4 secs.
During set-up, VEGA TOR is adapted to VEGASWING. The
actual resonance frequency is detected as current by
VEGATOR and stored as reference value.
Condition up to approx. 4 secs. after set-up:
Y ellow LED lights
VEGATOR 526 W Ex
Green LED in set-up key lights
on
Green LED lights
Condition up from approx. 4 secs. after set-up:
After electrical connection of VEGASWING Ex to
VEGATOR 526 W Ex the overfill protection goes to
operating status.
Operating status before set-up:
Y ellow LED lights
VEGATOR 526 W Ex
on
(= level relay de-energized)
Green LED in set-up key flashes
(= set-up not yet carried out)
Green LED lights
(= supply voltage on)
VEGATOR 526 W Ex
on
Green LED lights
Note:
- If the signal conditioning instrument VEGATOR
526 W Ex is exchanged by a new instrument of the
same type, the set-up must be repeated.
- The set-up of the continuous level measurement or
level detection is made acc. to the description in the TIB
of the signal conditioning instrument used.
VEGATROL 10 Ex 1
13
Page 14
4 Supplement
VEGATOR 526 W Ex
on
3.3 Operation
If in case of overfilling, the tuning fork is covered up to the
switch point with the liquid gas, the level relay deenergizes with a delay of approx. 500 msec. and the
respective LED lights.
This remains as long as the fork is covered.
If the level reduces below the switch point, the relay
energizes with a delay of approx. 1 sec. and the respective
LED extinguishes.
4 Supplement
4.1 Fault signals
There are two error classes concerning the condition of
the LED in the front panel:
- error during set-up
- error detected during self-monitoring.
Level and fail safe relays de-energize in both cases.
In case of failures during set-up, start again (switch off the
voltage and switch on again) and repeat the set-up acc. to
section 3.2.
If an error is detected, the voltage must be switched off
first, the failure (e.g. line break) removed and then the
voltage switched on again. It is not necessary to repeat the
set-up.
Failure reason Failure treatment
External failure Remove the fault and
(line break, short-circuit, start again
fault SWING-electronic)
Set-up was carried out Start again and repeat
when tuning fork was set-up with uncovered
covered tuning fork
Set-up key was pushed Start again and repeat
too long (> 6 secs.) set-up correctly
Error during self-monitoring
lights
VEGATOR 526 W Ex
on
Failure reason Failure treatment
Line break, Remove failure and start
short-circuit again
Component failure Inform VEGA-service or
lights
return the instrument for
investigation
Error during set-up
lights
lights for approx. 2 secs.
lights
14
VEGATROL 10 Ex 1
Page 15
4 Supplement
4.2 Calculation information for sensor length
The determination of the sensor length must be generally made with the respective expert.
Example: cylindrical tank
3000 mm
L
Volume 85 %
corresponds to 2400 mm
0 mm
600 mm distance from
flange lower edge to the
determined switch point
Procedure
- calculate the level of the max. permissible volume 85 %,
e.g. 2400 mm
- determine the distance from the flange lower edge up
to the calculated level
- determine the total length of VEGASWING
L = distance + 25 mm
(25 mm = submerging depth up to the switch point)
in this example:
L = 600 m + 25 mm = 625 mm
A VEGASWING with a total length of 625 mm must be
ordered.
Note:
An increase of the total length of VEGASWING will cause
the instrument to respond even at low levels, a reduction
causes a response at higher levels.
If the required total length cannot be exactly determined,
the calculated value must be rounded up (determination to
the safe side).
VEGATROL 10 Ex 1
15
Page 16
4 Supplement
4.3 General instructions for the use of overfill protections
Application of a liquid gas overfill protection (ÜFS) is to monitor the level of the liquid
gas stage and to interrupt the filling procedure when the permitted level in the vessel
is reached and to trigger an acoustic or optic alarm.
The configuration as well as the operation of such an overfill protection must always
meet with the requirements of an overfill protection as well as the special conditions
of the VdTÜV-regulation "overfill protection 100".
This furthermore requires that the filling of a pressuirzied vessel for liquid gas is only
possible if it is ensured that the overfilll protection works interferencefree and
correctly. At least before each filling procedure the whole measuring system of the
overfill protection must be checked. Normally this test of overfill protections is
triggered by a manually operated test key. In case of failure the filling must be
suppressed by a locking circuit.
Due to the self-monitoring, this test is not necessary with VEGATROL.
The overfill protection always operates discontinuously and can be planned and
operated independent from the function of the continuous level measurement. The
continuous level measurement is not subjected to the special requirements to the
functional reliability of the overfilll protection.
However both have to be included in an alarm system as follows:
- the continuous measurement generates the pre-alarm signal and controls an
acoustic or optic warning system or interrupts the filling procedure
- the overfill protection triggers a main alarm signal and stops the system
Criteria for dimensioning:
- triggering pre-alarm, e.g. at 83 % filling (dependent on the vessel geometry)
- triggering main alarm, generally at 85 % fllling
- tolerance of the switch point of the overfill protection: ± 1 %
The pre-alarm is adjusted such that there is sufficient time to avoid response of the
overfill protection.
VEGA Grieshaber KG
Postfach 11 42
D-77757 Schiltach
Phone 0 78 36 / 50 - 0
Fax 0 78 36 / 50 201
Technical data subject to alterations 2.16 207 / Sept. '94
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