Endress+Hauser Nivocompact FTC 131 Manual

Technical
Information
TI 133F/00/en
Applications
The Nivocompact FTC…is used for limit
detection in silos containing bulk solids
(for minimum or maximum level
indication). Three versions cover almost
any measuring application:
FTC 131 with rod probe ø 25 mm,
for mounting laterally or from above.
Mainly for maximum detection of
fine-grained or powdery bulk solids.
For minimum detection in small silos
with light bulk solids.
For use in the food processing industry.
Advantages:
•Complete unit consisting of probe with
plug-in electronic insert:
– simple mounting, low installation
costs
– for automation and control systems
(PLC, PCS, PC, relays, contactors,
etc.)
•No moving parts in silo:
– no wear, long operating life
– no maintenance
•Simple calibration:
– variable switchpoint with probes
mounted from above
•Rope version can be easily shortened:
– can be used for various limit values
– short delivery time
FTC 231 with rope probe ø 10 mm,
for mounting from above.
Mainly for maximum detection.
For minimum detection with light bulk
solids.
FTC 331 with rope probe ø 16 mm,
for mounting from above.
For maximum and minimum detection
with heavy bulk solids.
Capacitance Limit Detection
nivocompact FTC 131/231/331
Compact level limit switches for bulk solids
FTC 331
FTC 231
FTC 131
Hauser + Endress
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Application Examples Sand Glass aggregate
Gravel Moulding sand
Lime Ore, crushed
Plaster Aluminium shavings
Cement Grain
Pumice Flour
Dolomite Sugar beet chips
Kaolin Fodder
and similar bulk solids
The Nivocompact is an electronic switch.
The entire measuring system consists of:
•Nivocompact FTC…
•power supply and
•connected control systems, switches,
signal transmitters
(e.g. process control systems, PLC,
relays, microcontactors, lamps, sirens
etc.)
The probe (rod or rope) and the silo wall
form the two electrodes of a capacitor,
with a high frequency voltage between
them.
The limit value is based on the principle
of a discharge circuit:
As long as the probe is in air with a
dielectric constant of εr= 1, then the
discharge time constant is τ= R x CA
where R is the resistance of the circuit
and CAthe capacitance of the capacitor
formed by the probe and silo wall.
If bulk material with a high dielectric
constant moves into the electrical field
between the probe and silo wall, then
the capacitance CAincreases and with
it the time constant τ.
The change in the time constant is
evaluated and the Nivocompact is
activated according to its switching
mode.
Note:
Bulk solids should have dielectric
constants εr≥2.5.
The Nivocompact is extremely
insensitive to low build-up on the probe
and silo wall as long as the material
does not form a bridge between the
probe and wall (e.g. on the threaded
boss).
The Complete
Measuring System
TI133Y01
FTC 231/331 Power
supply
FTC 131
Power
supply
The capacitance
level limit switches
Nivocompact
FTC 131...FTC 331
in practice
Operation
TI133Y12
εr> 1εr= 1
The capacitor
consisting of the silo
wall and probe
2

Fail-Safe Mode
The built-in feature for minimum/
maximum fail-safe switching allows the
Nivocompact to be used in all
applications requiring high operational
safety:
•Maximum Fail-Safe:
The current circuit is blocked
if the probe is covered
or the power supply fails.
Electronic Insert EC 20
Two-wire AC connection
21 V…250 V
Electronic switch, max. 350 mA
Electronic Insert EC 22
Three-wire DC connection
10 V…55 V
Transistor circuit,
load connection PNP, max. 350 mA
•Minimum Fail-Safe:
The current circuit is blocked
if the probe is uncovered
or the power supply fails.
A red LED on the electronic insert
indicates switching status.
Electronic Insert EC 23
Three-wire DC connection
10 V…55 V
Transistor circuit,
load connection NPN, max. 350 mA
Electronic Insert EC 24
with potential-free relay output,
AC voltage operation
21 V…250 V or
DC voltage operation
20 V…200 V
TI133Y02
(load circuit closed)
(load circuit closed)
(load circuit open)
(load circuit open)
(load circuit open)
Minimum
fail-safe
mode
Maximum
fail-safe
mode
Power failure
Safety
Switching Level Electronic Switch
Full
Empty
Disconnected
Connected
Disconnected
Connected
Disconnected
The electronic switch
operates according to
the fail-safe switching
and the level.
Main Features of the
Different Electronic
Inserts
UU = U =
TI133Y13
U
U =
EC 20 EC 22 EC 23 EC 24
Electrical connections
available with the
different electronic
inserts.
3

Basic Differences
Between Probes
Nivocompact FTC 131
Rod probe, ø 25 mm
Insulation PE
Probe length 350 mm
Nivocompact FTC 231
Rope probe, ø 10 mm
Insulation PA
Probe length max. 22 m
Tensile load max. 3 t
Nivocompact FTC 331
Rope probe, ø 16 mm
Insulation PVC
Probe length max. 22 m
Tensile load max. 8 t
∅24
∅16
∅40
max. 80
100
approx. 250
L max. 22000 approx. 155
max. 88∅
TI133E20
60 AF
G 1½
or
NPT 1½"
Insulation
Steel rope
Partial insulation
Cast iron
Dimensions FTC 331
L max. 22000
approx. 250
approx. 140
∅10
∅40
max. 88∅
max. 80
∅20
TI133E19
60 AF
G 1½
or
NPT 1½"
Insulation
Steel rope
Partial insulation
Cast iron
55
Dimensions FTC 231
max. 80
approx. 140
L = 350
(Standard)
max. 88∅
∅25
TI133E18
60 AF
G 1½
or
NPT 1½"
Steel rod
Insulation PE
Dimensions FTC 131
4

Filling the Silo
The filling stream should not be directed
onto the probe.
Angle of Material Flow
Note the angle of material flow or the
outlet funnel when determining the
measuring point or probe length.
Distance Between Probes
If more than one probe is mounted in a
silo, then a minimum distance of 0.5 m
must be allowed for in order to avoid
mutual interference.
Threaded Socket for Mounting
Use the shortest possible threaded
socket when mounting the Nivocompact
FTC 131…331.
Condensation can form in long threaded
sockets and interfere with correct
operation of the probe.
Heat Insulation
With high silo temperatures:
Insulate the outside silo wall to avoid
exceeding the max. permissible
temperature of the Nivocompact
housing. This insulation also prevents
condensation near the threaded boss
and so reduces build-up and the
danger of error switching.
Installation in the Open
A protective sun cover as an accessory
protects the Nivocompact with the
aluminium housing from excessive
temperatures and from condensation
which may form in the housing due to
large temperature variations.
General information
for installing the
capacitance
Nivocompact FTC…
level limit switch.
TI133Y03
FTC 231
FTC 331
Distance
min.
500 mm
Angle of
slope
min.
500 mm FTC 131
max. 60 °C
Protective
sun cover
min.
500 mm
max. 80 °C
Protective
roof
approx.
200 mm FTC 131
Angle of
slope
Installation
General Information
5

Project Planning
Nivocompact FTC 131
a) Maximum level detection;
Short threaded socket (ideally 25 mm
= half standard length socket).
b) Light build-up on silo wall:
threaded socket welded internally.
The probe tip points slightly
downwards so that material falls off
more easily.
c) Protective roof to protect against
collapsing mounds or high strain on
the rod probe caused by the material
filling curtain with the Nivocompact
FTC 131 used for minimum detection.
d) Threaded socket too long.
Material can settle and lead to error.
e) Error switching caused by high
build-up on the silo wall is best
avoided by mounting the
Nivocompact FTC 231 or FTC 331
with rope probe in the roof of the silo.
f) High strain on the rod probe due to
material run-out;
The Nivocompact FTC 431 with disk
probe is recommended.
Cable gland pointed upwards can
allow moisture to enter.
g) In areas where material can settle,
the instrument cannot recognise an
»empty« silo. The FTC 231 or
FTC 331 is recommended.
This mounting example shows a steel
plate as counter electrode.
Heat insulation prevents condensation
and build-up on the steel plate.
When mounting in a silo made of plastic
material, a sheet metal plate should be
attached to the outside of the silo as a
counter electrode. This plate can be
either square or round. The dimensions
with thin silo walls and low dielectric
constant should be approx. 0.5 m on
each side or ø 0.5 m. This should be
approx. 0.7 m along each side or
ø 0.7 m for silos with thicker walls or for
materials with higher dielectric constants.
The minimum distance required can be
maintained by staggered mounting.
TI133Y04
Metal wall
a)
Short
b)
360
approx.
200
approx.
200 c)
d)
e)
f)
max.
30 Nm
g)
Silo with metal walls
TI133Y06
Plastic wall
Sheet metal plate
Ground connection
Electrical
HF field
Silo with concrete walls
TI133Y07
e.g.
300 mm e.g.
300 mm
min.
500 mm
TI133Y05
Concrete wall
Sheet metal plate
with threaded
socket
Heat insulation
min. ø 300
or 300
For small differences in
level
Silo with plastic walls
Correct Installation Incorrect Installation
6

Project Planning
Nivocompact FTC 231
and FTC 331
a) The correct distance from the silo
wall, the material filling curtain and
the material outlet.
For pneumatic filling systems, the
distance of the probe from the wall
should not be too small as the probe
may swing against it.
Silo Roof
Ensure that the silo roof is strong
enough!
Very high tensile forces, up to
100.000 N (10 t) may occur at the
material outlet especially with heavy,
powdery bulk materials which tend to
form build-up.
b) The probe can be damaged by the
inflowing material if mounted too near
the inlet.
When mounted near the centre of the
outlet, the high tensile forces present
at this point may damage the probe
or subject the silo roof to excessive
strain.
c) Threaded socket too long;
Condensation and dust may
penetrate and cause errors.
d) Too near silo wall;
When swinging gently the probe can
hit the wall or touch any build-up
which may have formed.
This can result in error switching
Coarse Grained Materials
The Nivocompact FTC 231 or FTC 331
should only be used for maximum
detection in silos with very coarse or
abrasive material.
Distance between Probes
A minimum distance of 0.5 m between
probes must be maintained to ensure
that there is no mutual interference;
This also applies to all Nivocompact
units which are mounted next to one
another in silos with non-conducting
walls.
TI133Y08
a)
approx.
0.1 L to
0.3 L
min.
0.4 m
b) c) d)
max. 3 t (FTC 231)
max. 8 t (FTC 331)
L
Silo with metal walls
Correct Installation Incorrect Installation
7

The 25 mm long threaded socket should
project into the silo so as to minimise
effects due to condensation and
material build-up.
★LB(covered length):
With non-conductive materials having
low dielectric constants, the rope probe
must be approx. 5 % (or minimum
300 mm) longer than the distance from
the roof of the vessel to the switch point.
If it is not possible to select the correct
LBfor minimum detection with very long
Heat insulation prevents condensation
and build-up on the steel plate.
When mounting in a silo made of
plastic, a counter electrode must be
mounted on the outside and at the same
height as the weight.
The length of the edge of the counter
electrode should be roughly the same
length as the distance of the weight to
the silo wall.
probes then a special version with
»butterfly weight« can be supplied as
an accessory. The increased surface
area of this weight ensures that there is
a large enough change in capacitance
when the probe is covered by material.
An LBof 300 mm is normally sufficient.
TI133Y09
Steel plate
connected to
the reinforcing
steel
Concrete
roof
recommended
with
condensation:
Heat
insulation
Steel plate
Silo with concrete walls
TI133Y10
Ground
connection
Surface
area
e.g.1 m2
Counter
electrodee.g.
sheet metal plate
Weight
Electrical
HF field Distance
e.g.1 m
TI133Y11
L
Limit
Electrically
conductive bulk
solid (e.g.ore)
L
Limit
LBmin. 200 mm
Bulk solid with high
dielectric constant
(e.g.meal)
L
min.0.05xL min.300 mm
LB★
Bulk solid with low
dielectric constant
(e.g.moulding sand)
Limit
Silo with plastic walls
Different probe lengths
8

Wiring Connections
General Information
Load Limit Values
Note the limit values of the loads to
which you want to connect the
Nivocompact. Exceeding the load can
destroy the electronic insert (or the relay
contact in the EC 24).
Fuse
Ensure that the rating of the fine-wire
fuse corresponds to the maximum load
to be connected;
the fine-wire fuse does not protect the
electronic insert of the Nivocompact
FTC.
Diameter of Wiring
Because of the small currents used,
only small diameter cabling is required.
Low-cost cabling with diameters of
0.5 mm2to max. 1.5 mm2is
recommended.
Grounding
The Nivocompact must be grounded to
give reliable operation free from
interference. This is done by either
connecting it to a grounded silo with
metal or reinforced concrete walls or
else to the earth conductor PE.
If a counter electrode is connected to a
silo made of plastic material then there
must be a short ground connection from
the Nivocompact to the counter
electrode.
Connecting the Nivocompact
with Electronic Insert EC 20
for AC Voltage
(Two-Wire Connection)
Connecting in series to a load
The level limit switch Nivocompact with
electronic insert EC 20 must - like all
switches - be connected in series with
the load (e.g. relays, microcontactors,
lamps) to the power supply.
Connection voltage
The voltage across Terminal 1 and 2
of the electronic insert must be at least
21 V.
The power voltage must be
correspondingly higher to compensate
for the voltage drop across the
connected load.
Load cutoff
Note that loads connected in series are
not completely disconnected from the
power supply if the electronic switch in
the electronic insert of the Nivocompact
»cuts off« (blocks) with the level alarm.
Because of the current requirements of
the electronics, a small »residual
current« still flows through the external
load.
When the load is a relay with a very
small retaining current, then the relay
may not de-energise. In this case
connect an additional load in parallel to
the relay, e.g. a resistor or signal lamp.
TI133Y14
EC 20
12
M
E
U
1-2∼
R
F
UR
L1 N PE
Power supply
U∼:min. 21 V + UR
max.250 V
Connecting the
Nivocompact with
EC 20 electronic insert
U 1-2∼: 21 V…250 V
across Terminals 1
and 2 of the EC 20
R: Connected
(external) load ;
e.g.relay
F: Fine-wire fuse,
load-dependent
M: Ground connection
to silo or to counter
electrode
E: Grounding
UR:Voltage drop
between the load
R and the fine-wire
fuse
Connecting the EC 20
9

Connecting the Nivocompact
with Electronic Insert EC 22
(Three-Wire PNP) or
Electronic Insert EC 23
(Three-Wire NPN)
for DC Voltage
Transistor circuit for load
The load connected to Terminal 3 is
switched by a transistor, contactless
and therefore without bouncing.
EC 22:
Terminal 3 has a positive signal
with normal switching.
EC 23:
Terminal 3 has a negative signal
with normal switching.
The transistor is blocked on level alarm
or with a power failure.
Protection against voltage peaks
Connecting to an instrument with a high
inductance:
a voltage limiter should be connected.
Connecting the Nivocompact
with Electronic Insert EC 24
(Relay Output)
for DC and AC Voltages
Relay contact for load
The load is connected over a
potential-free relay contact
(change-over contact).
The relay contact breaks the connection
between Terminal 3 and Terminal 4 on
level alarm or with a power failure.
Protection against voltage peaks and
short-circuiting
Protect the relay contact by connecting
a spark barrier to instruments with high
inductance.
A fine-wire fuse (load-dependent) can
protect the relay contact if a short-circuit
occurs.
Power Supply
TI133Y15
(+)
13
M
E
R
F
L+ L-
U=:10 V...55 V
2
(PE)
EC 22
+
TI133Y16
(–)
EC 23
13
M
E
R
F
L+ L-
U=:10 V…55 V
2
(PE)
TI133Y17
EC 24
13
M
E
U∼
or
U=
Potential-free
change over
contact
L1 N
U∼:21 V…250 V
or
u=:20 V…200 V
452
F
1F 2
au r
+– PE
Connecting the
Nivocompact with
electronic insert EC 23
NPN connection
F: Fine-wire fuse,
load-dependent
R: Connected load,
e.g. PLC, PCS,
relay
M: Ground connection
to silo or to counter
electrode
E: Grounding
Connecting the
Nivocompact with
electronic insert EC 24
Relay output
F1:Fine-wire fuse
200 mA, semi-time
lag recommended
F2:Fine-wire fuse to
protect the relay
contact, load-
dependent
M: Ground connection
to silo or to counter
electrode
E: Grounding
Connecting the
Nivocompact with
electronic insert EC 22
PNP connection
F: Fine-wire fuse,
load-dependent
R: Connected load,
e.g. PLC, PCS,
relay
M: Ground connection
to silo or to counter
electrode
E: Grounding
Connecting the
EC 22, EC 23
Connecting the EC 24
10