Endress+Hauser nivocompact FTC 831 User manual

nivocompact
FTC 831
Level Limit Switch
Installation and Operating Manual
BA 024F/00/en/07.98
015191-0001
Hauser + Endress
The Power of Know How

Contents Page
Application 3
Application Examples 3
Technical Data 4
The Measuring System 7
Function 8
Installation 9
Project Planning 9
Examples for Mounting 10
Mounting 11
Type key 11
Connection 13
Wiring Connection 13
EC 40 (Two-Wire Connection) for AC 14
EC 42 (Three-Wire PNP) for DC 15
EC 43 (Three-Wire NPN) for DC 16
EC 44 (Relay output) for DC and AC 17
Wiring On-Site 18
Calibration 19
Switching Delay 19
Safety Switching 20
Special Applications 21
Function Control 23
Maintenance 23
Troubleshooting 23
Replacement of Parts 25
Returning Parts for Repair 25
Shortening the Cable 26
1

Nivocompact FTC 831
2

Application
The Nivocompact FTC 831 is used for limit detection in silos containing bulk
solids (for minimum or maximum indication).
Also for use in the food processing industry.
For mounting in silos from above.
Application Examples
Lime Kaolin Grain Spices
Plaster Plastic Flour Semolina
Cement granulates Fodder
and similar bulk solids
Note:
Bulk solids should have dielectric constants εr≥1.6.
Please contact us for advice if the dielectric constant of the bulk solid is not
known.
Fig. 1
Limit detection in bulk solid silos with the
capacitive level limit switch Nivocompact
FTC 831.
Application
3

Technical Data
Operating Data •Operating temperature in silo: –20 °C…+60 °C
•Operating pressure pein silo: up to 6 bar
•Max. permissible load on probe: 2500 N vertical
•Grain size of bulk solid: up to approx. 10 mm
•Minimum dielectric constant εrof material: 2.0
(factory-set, no adjustment required)
•Minimum adjustment of dielectric constant εrfor bulk solid: 1.6
•Ambient temperature for housing: –20 °C…+60 °C
•Storage temperature: –40 °C…+85 °C
Probe •Construction: rope probe with electronics at end of probe
•Process connection: parallel thread G 11/2A acc. to DIN ISO 228/I
•Process connection material: glass-fibre reinforced polyester (PBTP)
•Probe material: reinforced steel wire mesh and electronics with PE coating
•Insulation from material: fully insulated
Probe Length Tolerances Probe length Tolerance
up to 1 m +0 mm, –5 mm
up to 3 m +0 mm, –10 mm
up to 6 m +0 mm, –20 mm
up to 20 m +0 mm, –30 mm
Housing Versions •Aluminium housing, IP 55
•Aluminium housing, IP 66
•Aluminium housing with synthetic coating, IP 66
•Synthetic housing in PBTP, IP 66
(Protection IP…acc. to DIN 40050)
Cable Gland •Housing IP 55: standard PG in nickel-plated brass with NBR gasket for
cable diameter 7…10 mm.
•Housing IP 66: water-tight PG in polyamide with Neoprene-CR gasket
for cable diameter 5…12 mm
Nivocompact FTC 831 Technical Data
4

Fig. 2
Dimensions Nivocompact FTC 831
Technical Data
5

Electronic Inserts •Terminal connections: for max. 2.5 mm2
•Measuring frequency: approx. 1.6 MHz
•Switching delay: approx. 0.5 s…approx. 20 s, selectable
•Minimum/maximum fail-safe switching: selectable with rotary switch
•Switching indication: red LED
•Power supply U∼: 21 V…250 V, 50/60 Hz
•Connected loads, short-term (max. 40 ms): max. 1.5 A;
max. 375 VA at 250 V;
max. 36 VA at 24 V
•Maximum voltage drop: 11 V
•Connected loads, continuous: max. 350 mA;
max. 87 VA at 250 V;
max. 8.4 VA at 24 V
•Minimum load current at 250 V: 10 mA (2.5 VA)
•Minimum load current at 24 V: 20 mA (0.5 VA)
•No-load current (rms): < 5 mA
•Power supply U =: 10 V…55 V
•Superimposed AC voltage Upp: max. 5 V
•Current consumption: max. 15 mA
•Load connection: Open Collector; PNP (EC 42) or NPN (EC 43)
•Switching voltage: max. 55 V
•Connected load, short-term (max. 1 s): max. 1 A
•Connected load, continuous: max. 350 mA
•Residual current with transistor blocked: < 100 µA
•Protected against reverse polarity
•Power supply U =: 20 V…200 V
or
Power supply U∼: 21 V…250 V, 50/60 Hz
•Current consumption (rms): max. 5 mA
•Peak inrush current: max. 200 mA, max. 5 ms
•Pulse current: max. 50 mA, max. 5 ms
•Pulse frequency: approx. 1.5 s
•Output: potential-free change-over contact
•Contact load capacity:
U∼max. 250 V, I∼ max. 6 A,
P∼max. 1500 VA (cos ϕ= 1) or P∼max. 750 VA, (cos ϕ ≥ 0.7)
U = max. 250 V, I = max. 6 A, P = max.200 W
•Operating life: min. 105switchings at max. contact load
•Additional switching delay: max. 1.5 s
Type Key See Page 11 for order specification key and order code.
EMC Electromagnetic compatibility:
•Interference Emission to EN 61326, Electrical Equipment Class A
•Interference Immunity to EN 61326
•EMC Test Procedures see TI 241F/00/en
Subject to modification
Electronic Insert EC 40
for AC
(Two-Wire Connection)
Electronic Inserts EC 42, EC 43
for DC
(Three-wire Connection)
Electronic Insert EC 44
for DC and AC
(Relay Output)
Nivocompact FTC 831 Technical Data
6

Accessories•Gasket for thread G 11/2A;
elastomer/fibre (asbestos-free) supplied
•Protective sun cover for aluminium housing
Material: polyamide
The Measuring System
The Nivocompact is an electronic switch.
The entire measuring system consists of:
•Nivocompact FTC 831
•power supply and
•connected control systems, switches, signal transmitters (e.g. process
control systems, PLC, relays, microcontactors, lamps, sirens etc.).
Fig. 3
Dimensions of protective sun cover
(accessory).
This cover prevents condensation in the
housing.
Fig. 4
The measuring system.
The Measuring System
7

Function
A metal plate at the end of the probe, inside the insulation, and the area
around it (e.g. silo wall) constitute 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 end of the probe is in air with a dielectric constant of εr= 1,
then the discharge time constant is τ= R x CAwhere R is the resistance of
the circuit and CAthe capacitance of the capacitor formed by the probe
end and its surroundings.
If a material with a dielectric constant εr≥2.0 moves into the HF electrical
field at the end of the probe, then the capacitance CA increases and with it
the time constant τ.
This change in the time constant is evaluated and the Nivocompact FTC
831 is activated according to its switching mode.
Safety Switching 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 circuit is blocked if the probe is covered
or the power supply fails.
Minimum Fail-Safe:
The circuit is blocked if the probe is uncovered
or the power supply fails.
A red LED on the electronic insert indicates the switching status.
See also Fig. 16 in Section »Safety Switching«, Page 20.
Fig. 5
The operation of the Nivocompact FTC 831
with rope probe is totally unaffected by
material build-up on the walls of the silo.
Nivocompact FTC 831 Function
8

Installation
Project Planning
Material of the Silo
The Nivocompact FTC 831 can be installed in silos made of different
materials (e.g. metal, plastic, concrete).
Installation Point
Note the angle of material flow or the outlet funnel when determining the
measuring point.
The Nivocompact switches (also with bulk solids with very small dielectric
constants) when the probe end is covered by a few centimetres of material
or when the material drops a few centimetres below the probe end.
The filling curtain should not be directed onto the probe.
Minimum Distance
The minimum distance of 500 mm between the probe ends of two
Nivocompact FTC 831 instruments must be maintained to ensure that there
is no mutual interference, this also applies to all FTC 831 probes which are
mounted next to one another in silos with non-conducting walls.
The distance from the probe end of an FTC 831 to the probe end of an
FTC 731 must also be at least 500 mm.
The distance from the probe end of a Nivocompact FTC 831 to the silo wall
or to any material build-up must be at least 200 mm. To ensure that no error
switching occurs when the probe swings slightly, the distance of the probe
to the silo wall should be correspondingly greater, especially with
pneumatic conveying systems.
Resistance to Load
With minimum detection, take note of the maximum load of the rope and the
strength of the silo roof.
Very high tensile forces may occur at the material outlet especially with
heavy powdery bulk materials which tend to form build-up.
These forces are significantly greater in the middle of the silo over the
material discharge point than at the silo walls.
Installation in the Open
The protective sun cover available as an accessory protects the
Nivocompact with the aluminium housing from excessive temperature and
from condensation which may form in the housing due to large temperature
variations.
Installation
9

Examples for Mounting
Correct Installation a) Protective sun cover for mounting in the open.
b) Sufficient distance from the material inlet and to the next probe.
c) Sufficient distance to the silo wall and to material deposited on the silo
wall.
Incorrect Installation d) 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.
e) Too near the 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.
Inflowing material can damage the probe
There is the danger of static electricity building up.
Correct Installation Incorrect Installation
Fig. 6
Noting the information given will prevent
errors when installating the instrument.
Nivocompact FTC 831 Installation
10

Mounting
•Open-end spanner 60 AF
•Screwdriver, blade width 5...6 mm or
Phillips screwdriver PZD 2
Preparation
Compare the order code on the nameplate of your instrument with the order
specification key to ensure that the correct instrument is being installed.
Check that the probe is the correct length for the installation point and
application.
The length of the Nivocompact FTC 831 probe at delivery is stated on the
nameplate.
The probe may be shortened if it is too long. Refer to Section: »Shortening
the Cable« at the end of this manual.
Screwing In•Place the elastomer/fibre gasket which is supplied against the sealing
surface of the Nivocompact. (Do not apply sealing material around the
thread!)
•Straighten out the cable at the lower end.
•Feed the cable carefully through the threaded boss making sure that the
insulation is not damaged.
•When screwing in the Nivocompact, turn the instrument by the 60 AF nut
only!
•If the instrument will not turn easily, then slightly cut into the thread of the
boss.
•A torque of 80 Nm…100 Nm is normally sufficient to produce a reliable
seal to withstand pressures up to 6 bar.
A torque of more than 120 Nm will destroy the plastic thread.
Tools Required for Mounting
Probe
1…mm probe length
Probe lengths from 500 to 20000 mm, selectable
2 2500 mm (basic length, can be shortened)
6 6000 mm (basic length, can be shortened)
9 Others - check special version
Housing
A Aluminium housing, IP 55
B Aluminium housing, IP 66
R Aluminium housing, coated, IP 66
K PBTP synthetic housing, IP 66
Y Others - check special version
Electronic Insert (mounted in housing)
1 21 V…250 V, 50/60 Hz (EC 40)
Two-wire AC connection
2 PNP 10 V…55 V= (EC 42)
Three-wire DC connection
3 NPN 10 V…55 V= (EC 43)
Three-wire DC connection
4 Relay, 21 V…250 V AC/200 V= (EC 44)
AC or DC connection
with relay output (change-over contact)
9 Others - check special version
Order code on nameplate
FTC 831
FTC 831 capacitive level limit switch with rod probe
Installation
11

Rotating the Housing The housing can be rotated if the cable gland is facing in the wrong
direction after the Nivocompact has been securely screwed in:
Loosening
•Unscrew and remove the housing cover.
In the housing are 2 four-pole connections which are required if the cable
needs to be shortened. These should be kept in a safe place.
•Loosen the central screw in the electronic insert.
•Remove the plug-in electronic insert from the housing using the handle.
•Slightly loosen the 3 screws in the housing, see Fig. 7.
Rotating
•The housing can now be rotated through 360°.
Tightening
•Tighten up the 3 screws in the housing so that the housing is well sealed
at the hexagonal nut.
•Insert the electronic insert in the plug.
•Securely tighten the central mounting screw
while making sure that the cable gland remains free.
Fig. 7
Loosening and rotating the housing.
Fig. 8
Securing the electronic insert.
Nivocompact FTC 831 Installation
12

Connection
Wiring Connection
Main Features of the Different
Electronic Inserts
The last number of the order code on the nameplate identifies which type of
electronic insert is mounted in the Nivocompact FTC 831:
1=Electronic insert EC 40
Two-wire AC; voltage: 21 V…250 V
Electronic switch, max. 350 mA
2=Electronic insert EC 42
Three-wire DC; voltage: 10 V…55 V
Transistor circuit, load connection PNP, max. 350 mA
3=Electronic insert EC 43
Three-wire DC; voltage: 10 V…55 V
Transistor circuit, load connection NPN, max. 350 mA
4=Electronic insert EC 44
with potential-free relay output
AC power supply 21 V…250 V or
DC power supply 20 V…200 V
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 44).
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 current used, only small diameter cabling is required.
Low-cost cabling with diameters of 0.5 mm2to max. 1.5 mm2is
recommended.
Earth Connection, 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.
The probe requires a good counter potential which is achieved by
connecting the ground connection on the outside of the housing to an
electrically conductive part of the silo.
If the silo is made of non-conductive material, then connect conductive and
grounded components near to the silo to the ground connection.
The connecting cable should be as short as possible.
Fig. 9
Electrical connections available with the
different electronic inserts
Connection
13

Connecting the Nivocompact with Electronic Insert EC 40
for AC (Two-Wire Connection)
Connecting in Series to a Load The level limit switch Nivocompact with electronic insert EC 40 must be
- like all switches - connected in series with the load (e.g. relays,
microcontactors, lamps) to the power supply.
Direct connection to the power supply without any intermediate load
connected (short-circuit!) will result in immediate and permanent damage to
the electronic insert.
The load can be connected to Terminal 1 or 2 of the electronic insert.
It is unimportant whether L1 is connected to Terminal 1 or 2.
Power Voltage The voltage across Terminal 1 and 2 of the electronic insert must be
correspondingly higher to compensate for the voltage drop across the
connected load.
Load Cut off 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 »disconnects« (blocks) with level alarm.
Because of the current requirements of the electronics, a small »no-load
current« still flows through the connected load.
When the load is a relay with a very small retaining current, it is possible
that the relay does not de-energise. In this case connect an additional load
in parallel to the relay, e.g. a resistor or signal lamp.
Fig. 10
Connecting the Nivocompact FTC 831
with electronic insert EC 40
U
1-2∼
: 21 V...250 V across Terminals 1 and 2
of the EC 40
R: Connected (external) load, e.g. relay
F: Fine-wire fuse, load-dependent
U
R
: Voltage drop across the load
and the fine-wire fuse
M: Ground connection to silo or
metal parts near to the silo
E: Grounding
Nivocompact FTC 831 Connection
14

Connecting the Nivocompact with Electronic Insert EC 42
(Three-Wire PNP) for DC
Transistor Circuit for Load
The load connected to Terminal 3 is switched by a transistor, contactless
and therefore without bounce.
Terminal 3 has a positive signal in normal switching mode.
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.
Fig. 11
Connecting the Nivocompact with electronic
insert EC 42 (PNP connection)
F: Fine-wire fuse, load-dependent
R: Connected load, e.g. PLC, PCS, relay
M: Ground connection to silo or
metal parts near to the silo
E: Grounding
Connection
15

Connecting the Nivocompact with Electronic Insert EC 43
(Three-Wire NPN) for DC
Transistor Circuit for Load The load connected to Terminal 3 is switched by a transistor, contactless
and therefore without bounce.
Terminal 3 has a negative signal in normal switching mode.
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.
Fig. 12
Connecting the Nivocompact with electronic
insert EC 43 (NPN connection)
F: Fine-wire fuse, load-dependent
R: Connected load, e.g. PLC, PCS, relay
M: Ground connection to silo or
metal parts near to the silo
E: Grounding
Nivocompact FTC 831 Connection
16

Connecting the Nivocompact with Electronic Insert EC 44
(Relay output) for DC and AC
Power Supply
With AC, it is unimportant whether L1 or N is connected to Terminal 1.
With DC, it is unimportant whether L+ or L– is connected to Terminal 1.
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.
Fig. 13
Connecting the Nivocompact with electronic
insert EC 44; (relay output)
F
1
: Fine-wire fuse 200 mA, semi-time lag,
F
2
: Fine-wire fuse to protect the relay
contact, load dependent
M: Ground connection to silo or
metal parts near to the silo
E: Grounding
Connection
17

Wiring On-Site
•Open-end spanner 22 AF
•Screwdrivers, blade width approx. 4 mm and approx. 7 mm or
Phillips screwdrivers PZD 1 and PZD 2
•Common electrical tools
Before connecting, make sure that the power supply used is the same as
that stated on the nameplate of the electronic insert.
Electrical Connections Connect the Nivocompact according to the appropriate diagram Fig. 10 to
Fig. 13.
Ensure that no water gets into the housing while connecting up.
The gasket in the standard cable gland is designed for cable diameters
from 7 mm to 10 mm.
A suitable gasket must also be used for other cable diameters.
You can seal with the "water-tight" cable gland with cable having diameters
from 5 mm to 12 mm.
Ensure that there is a good short ground connection from the housing of
the Nivocompact to the silo or to grounded metal parts near to the silo.
After Connecting Screw in the thread of the cable gland securely to comply with the
standards of Protection IP 55 or IP 66.
For applications in the open or in moist surroundings, sealing the standard
cable gland with sealing compound is also recommended.
(This is not required with the »water-tight« cable gland).
Tools Required for Connection
Fig. 14
Note the power voltage stated on the
nameplate.
Nivocompact FTC 831 Connection
18