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