Endress+Hauser nivotester FTL 325 P Manual

Technical Information
TI 350F/00/en Level Limit Switch
nivotester FTL 325 P
With intrinsically safe signal circuit for connection to
the Liquiphant and Soliphant measuring sensor
Applications
•Level limit detection in liquid tanks and
bulk material silos, also in hazardous
explosion areas
•For Zone 0 or Zone 20 measuring
sensors
•Liquid detection in pipes for dry
running protection for pumps
•Overspill protection for tanks with
combustible or non-combustible
liquids harmful to water
•Two-point control and level limit
detection with one switching instrument
•Application in safety related systems
with requirements for functional safety
up to SIL3 in accordance to IEC 61508
when using Liquiphant M/S with
electronic insert FEL 57
Benefits at a glance
•Intrinsically safe signal circuits [EEx ia]
for problem-free use of measuring
sensor in explosion hazardous areas
•Highest functional SIL safety (see also
Safety Manual SD 111) through:
– fault-free PFM technology
– line monitoring through to sensor
– corrosion monitoring on tuning fork of
Liquiphant M measuring sensor
•Compact housing for simple series
installation on standard rails in switch
cabinet
•Simple wiring using pluggable terminal
blocks
•Simple iterative test acc. to WHG by
connecting a Liquiphant M and S (high
temperature): one-touch operation
•High test depth: from isolating amplifier
through to measuring sensor

2
Functions and system design
Measuring principle Signal transmission
The intrinsically safe signal input of the Nivotester FTL 325 P limit switch is galvanically isolated
from the mains and the output.
The Nivotester powers the Liquiphant or Soliphant measuring sensors with a two-wire DC loop
and receives a frequency which signals whether or not the limit has been reached.
The power supply is superimposed with current pulses (PFM signals) from the measuring
transmitter. They have a pulse width of approx. 200 µs and a current strength of approx. 10 mA.
Signal evaluation
The Nivotester evaluates the frequency and switches the output relay for the level alarm.
The relay switching state is displayed by a yellow LED on the front panel of the Nivotester.
Fail-safe circuit
By correctly selecting the fail-safe circuit, you can ensure that the relay always works with
quiescent current safety.
•Maximum safety: the relay drops out when the switching point is exceeded
(measuring sensor covered), a fault occurs or the power supply fails.
•Minimum safety: the relay drops out when the switching point is undershot
(measuring sensor uncovered), a fault occurs or the power supply fails.
L00-FTL325Px-15-06-xx-en-001
Function of the level limit signal and the current pulse dependent on level and fail-safe circuit.
For application with requirements for functional safety in accordance to IEC 61508 (SIL),
please note Safety Manual SD 111F.
Ica.150 Hz
t
Ica.150 Hz
t
I
t
ca.50 Hz
I
t
ca.50 Hz
Tuning fork
free
Tuning fork
covered
Level
Maximum
safety circuit
Minimum
safety circuit
Current pulseCurrent pulse
Current pulseCurrent pulse
CH1...3
CH1...3
CH1...3
CH1...3
4 5 6
22 23 24
26 27 28
4 5 6
22 23 24
26 27 28
4 5 6
22 23 24
26 27 28
4 5 6
22 23 24
26 27 28

3
Function monitoring
To increase operating safety, the Nivotester is equipped with a function monitoring system.
A fault is indicated by a red LED and causes the level alarm relay in the affected channel as well
as the fault alarm to drop out. A fault is signalled when the Nivotester receives no more current
pulses. This could occur for example in the event of a short-circuit, an interruption in the signalling
line to the measuring sensor, vibrator corrosion in the Liquiphant, a defect in the measuring
sensor electronics or a defect in the input circuit of the Nivotester. The function of each channel
can be monitored by pressing the test button. The power supply to the sensor is then interrupted.
Simplified iterative test for Liquiphant M and Liquiphant S (HT)
Regular function checks are a statutory requirement for overspill protection systems. For the
Nivotester and the downstream plant sections, there is the possibility of a function test without
starting up or removing the sensor. For this reason, the Nivotester has a test button on the front
panel for each singal input. Pressing the test button interrupts the power supply. When the test
button is released, the power supply is returned to the Liquiphant and the FEL 57 and the test
phase begins. You can find detailed information on this in KA 147F.
L00-FTL325Px-19-06-xx-xx-001
Two-point control (∆s)
Two-point control is possible in one tank using the three-channel Nivotester (e.g. for pump
control). The switching hysteresis is specified by the installation location of the two measuring
sensors.
Measuring system A simple measuring device consists of one to three measuring sensors, a 1- or 3-channel
Nivotester and control or signal devices. A Liquiphant M, Liquiphant S (high temperature) or
Soliphant can be used as measuring sensor.
[Ex ia]
CH1 CH2
CH3
CH1 CH2 CH3
T
FTL 325 P

4
1-channel Nivotester FTL 325 P-#1#1
The measuring device of the 1-channel instrument consists of:
– 1 measuring sensor
– 1-channel Nivotester
– control or signal devices
L00-FTL325Px-14-06-xx-xx-001
3-channel Nivotester FTL 325 P-#3#3
There are five possible variants of the measuring device in the three-channel instrument.
L00-FTL325Px-14-06-xx-xx-002
L00-FTL325Px-14-06-xx-xx-003
1. When all three individual channels are used for measuring the level limit, the measuring
device consists of:
– 3 measuring sensors
– 3-channel Nivotester
– control or signal devices
2. When channels CH2 and CH3 are used for two-point control ∆s, the measuring device
consists of:
– 2 measuring sensors
– 3-channel Nivotester
– control or signal devices
E
X
E
X
FTL 325 P-#1#1
E
X
E
X
FTL 325 P-#3#3
CH1
CH2
CH3
E
X
E
X
FTL 325 P-#3#3
CH2
CH3
∆s
WHG SIL

5
L00-FTL325Px-14-06-xx-xx-004
L00-FTL325Px-14-06-xx-xx-005
L00-FTL325Px-14-06-xx-xx-006
!Note!
As CH1 is not used, the alarm must be switched to "off"!
3. When channels CH2 and Ch3 are used for two-point control ∆s and channel CH1 for overspill
protection, the measuring device consists of:
– 3 measuring sensors
– 3-channel Nivotester
– control or signal devices
4. When channel CH2 is used for measuring the level limit with two level limit relays and channel
CH1 is used for measuring other level limits, the measuring device consists of:
– 2 measuring sensors
– 3-channel Nivotester
– control or signal devices
5. When channel CH2 is used for measuring the level limit with two level limit relays, the
measuring device consists of:
– 1 measuring sensor
– 3-channel Nivotester
– control or signal devices
CH2
CH1
CH3
FTL 325 P-#3#3
∆s
E
X
E
X
WHG SIL
E
X
E
X
CH2
CH3
CH1
FTL 325 P-#3#3
E
X
E
X
CH2
CH3
CH1
FTL 325 P-#3#3

6
Input parameters
Measured variable The limit signal can be triggered at minimum or maximum height as required
Measuring range The measuring range is dependent on the installation location of the sensors
Input signal •Input FTL 325 P: galvanically isolated from power supply and output
•Protection type: intrinsically safe [EEx ia] IIC
•Connectable measuring sensors:
– Liquiphant DL 17 Z, with electronic insert EL 17 Z
– Liquiphant II FDL 30, FDL 31, FDL 35, FDL 36, with electronic insert FEL 37
– Liquiphant M FTL 50/51, FTL 50H/51 H, FTL 51 C, with electronic insert FEL 57
– Liquiphant S (HT) FTL 70/71, with electronic insert FEL 57
– Soliphant DM 90 Z, DM 91 Z, DM 92 Z, with electronic insert EM 17 Z
– Soliphant II FTM 30 S, FTM 31 S, FTM 32 S, with electronic insert FEM 37
•Measuring sensor power supply: from Nivotester FTL 325 P
•Connecting line: two-wire, screening unnecessary
•Line resistance: max. 25 Ωper wire
•Signal transmission: pulse frequency modulation (PFM)
Output parameters
Output signal •Relay output per channel: one potential-free switch contact for the level alarm
•Quiescent current safety circuit: minimum/maximum safety selectable with DIL switch
•Common fault signal relay: potential-free switch contact for fault signalling, of which only two
contacts are routed out
•Switch delay: approx. 0.5 s
•Switching power of the relay contacts:
U ~ max. 253 V
I ~ max. 2 A
P ~ max. 500 VA at cos ϕ≥0,7
U = max. 40 V
I = max. 2 A
P = max. 80 W
•Life: at least 105switching operations at maximum contact load
•Function displays: LEDs for operation, level alarm and fault
Overvoltage category acc.
to EN 61010
II
Protection class II (double or increased insulation)
Failure signal Level limit value relay dropped out; fault signal by red LEDs, fault signal relay dropped out
Galvanic isolation All input and output channels and relay contacts are galvanically isolated from each other

7
Power supply
Electrical connection Terminal blocks
The removable terminal blocks are separated into intrinsically safe connections (at top of the
instrument) and non-instrinsically safe connections (at bottom of the instrument). Also, the
terminal blocks have different colours to make them more easily recognisable. Blue for the
intrinsically safe section and grey for the non-intrinsically safe section. This difference helps to
ensure safe wiring.
Connecting the measuring sensor
(at upper, blue terminal blocks)
The two-wire connecting line between the Nivotester FTL 325 P and the Liquiphant or Soliphant
measuring sensor can be either a commercially available installation cable or wires in a multi-wire
cable for measuring purposes. Line resistance may be a maximum of 25 Ωper wire.
If strong electromagnetic interference is expected, e.g. from machines or radio devices, a
screened cable must be used. Only connect the screen to the ground connection, and not to the
Nivotester.
Installing the measuring sensor in explosion hazardous areas
Please observe all local regulations on explosion protection concerning the type and installation
of intrinsically safe signal cabling.
Please refer to the Safety Instructions XA 133F for maximum permissible values of capacitance
and inductance.
Connecting signalling and control devices
(at lower, grey terminal blocks)
The relay function is dependent on the level and the fail-safe circuit.
If an instrument is connected at high inductance (e.g. contactor, solenoid valve etc.), a spark
suppressor must be installed to protect the relay contact.
Connecting the supply voltage
(at lower, grey terminal blocks)
For voltage variants, see the Ordering Information on page 13.
A fuse is built into the power supply circuit. This obviates the need to connect a fine-wire fuse in
series. The Nivotester is equipped with reverse polarity protection.
Supply voltage AC version:
•Voltage range: 85...253 V AC, 50/60 Hz
DC version:
•Voltage range: 20...30 V AC / 20...60 V DC
•DC supply: max. 75 mA (1-channel)
•DC supply: max. 165 mA (3-channel)
•Permissible residual ripple within tolerance: Uss = max. 2 V
Power consumption AC
1-channel: max. 1.7 W
3-channel: max. 4.2 W
DC
1-channel: max. 1.5 W (bei Umin 20 V)
3-channel: max. 3.3 W (bei Umin 20 V)

8
Accuracy
Settling time/length Final switching status after switching on the power supply: approx. 10...40 s, depending on the
connected measuring sensor.
With Liquiphant M and Liquiphant S (high temperature) note the self-test function of the FEL 57
electronic insert.
Operating conditions (Installation conditions)
Installation instructions Operating location
The Nivotester must be housed in a switch cabinet outside the explosion hazardous area.
A protective housing (IP65) for up to four 1-channel or two 3-channel Nivotesters is available for
outdoor installation.
L00-FTL325Px-11-06-xx-xx-001
Installation position
Vertical on DIN top-hat rail (TS 35 to EN 50022).
L00-FTL325xx-11-06-xx-xx-001
min. IP 65
E
X
E
X
PFM
PFM
Liquiphant FTL
Soliphant FTM
U~
U–
~
CH1 CH2 CH3
FTL 325 P
EN 50022; 35 x 7,5
EN 50222, 35 x 15
[Ex ia]
CH1 CH2
CH3
CH1 CH2 CH3
T
FTL 325

9
Operating conditions (Ambient conditions)
Operating location Switch cabinet or protective housing
Permissible ambient
temperatures For single installation
•–20 °C...+60 °C (–4 °F...+140 °F)
For rail mounting without gaps
•–20 °C...+50 °C (–4 °F...+122 °F)
Storage temperature
•–20 °C...+85 °C (preferably at +20 °C)
(–4 °F...+140 °F (preferably at +68 °F))
Installation in protective housing
•–20 °C...+40 °C
•Up to four 1-channel or two 3-channel Nivotesters fit in one protective housing.
By combining these types of instrument, please note that only two 1-channel and one 3-channel
are applicable.
"Caution!
Select a mounting location which protects the instruments from weather and impacts.
Do not install them in direct sunlight. This is particularly important in regions with a warm climate.
Climatic application class 3K3
According to EN 60721-3-3
3M2
According to EN 60721-3-3
Ingress protection IP20
Electromagnetic
compatibility (EMC)
Interference emission to EN 61326; Electrical Equipment Class B
Interference immunity to EN 61326; Annex A (Industrial) and
NAMUR Recommendation NE 21 (EMC)

10
Mechanical construction
Construction, dimensions •Housing: plastic rail-mounting housing (Minipac construction)
•Installation: on top-hat rail to EN 50022 - 35 x 7.5 or EN 50022 - 35 x 15
•Ingress protection to EN 60529; IP20
!Note!
100 mm = 3.94 in
L00-FTL325xx-06-06-xx-xx-001
Dimensions
L00-FTL325xx-06-06-xx-xx-002
Weight •1-channel: approx. 148 g
•3-channel: approx. 250 g
min. 50 mm
min.
50 mm
min.
50 mm
FTL 325 CH3
FTL 325 CH3
FTL 325 CH3
FTL 325 CH3
FTL 325 CH1
FTL 325 CH1
FTL 325 CH1
FTL 325 CH1
FTL 325 CH1 FTL 325 CH1
? ? ? ? ?
E
X
E X
E
X
FTL 325 CH3
FTL 325 CH1
x2
x2
x1
x1
45 mm 112 mm
95 mm
108 mm
22,5 mm
FTL 325 CH3 FTL 325 CH1