Endress+Hauser FTL70 Specifications

TI00354F/00/EN/13.16
71310307

Products Solutions Services

Technical Information

Liquiphant S FTL70, FTL71

Vibronic

High-temperature point level switch for all types
of liquids

Application

The Liquiphant S is a point level switch for use in all types of liquids
– for process temperatures between –60 °C and 280 °C (–76 °F to 540 °F)

(300 °C (572 °C) for max. 50 cumulative hours; without thermal shock restriction)
– for pressures up to 100 bar (1450 psi)
– for viscosities up to 10,000 mPa*s (cSt)
– for density  0.5 g/cm
– Foam detection on request

The function is not affected by flow, turbulence, bubbles, foam, vibration, solids
content or buildup, making the Liquiphant an ideal substitute for float switches.

FTL70: Compact design, for pipes also
FTL71: Extension pipe up to 3 m (9.8 ft) and up to 6 m (20 ft) on request

For use in very aggressive liquids, the fork and process connection are available in the
highly corrosion-resistant material AlloyC22 (2.4602).

EEx ia, EEx de and EEx d protection enable it to be used in hazardous areas.

Your benefits

• Use in safety systems requiring functional safety to SIL2 in accordance with IEC

61508/IEC 61511-1

• Welded, gas-tight feed-through ensures maximum safety, even in the event of

damage to sensor

• With process connections from ¾" and small fork dimensions, it is also suitable

where space is tight.

• A wide range of process connections allows for universal application.

• The right connection for every process control system: e.g. NAMUR, relay, DC-PMP,

•PROFIBUS PA interface

• No adjustment: quick, low-cost startup

• No mechanical moving parts: maintenance-free



(SGU) or  0.7 g/cm(SGU), other configurations on request

Table of contents

Liquiphant S FTL70, 71

Application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Point level detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Function and system design . . . . . . . . . . . . . . . . . . . . . .4

Measuring principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Modularity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Electronic versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Galvanic isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Measured variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Measuring range (detection range) . . . . . . . . . . . . . . . . . . . . . . 5

Process density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Electronic insert FEL51 (AC 2-wire) . . . . . . . . . . . . . . .6

Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Output signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Signal on alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Connectable load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Electronic insert FEL52 (DC PNP). . . . . . . . . . . . . . . . . .8

Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Output signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Signal on alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Connectable load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Electronic insert FEL57 (PFM) . . . . . . . . . . . . . . . . . . 13

Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Output signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Signal on alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Connectable load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Electronic insert FEL50A (PROFIBUS PA) . . . . . . . . . 15

Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Output signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Signal on alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Connection and function . . . . . . . . . . . . . . . . . . . . . . . 16

Connecting cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Safety mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Switching time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Switch-on behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Reference operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . 16

Maximum measured error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Repeatability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Influence of process temperature . . . . . . . . . . . . . . . . . . . . . . . 17

Influence of process density . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Influence of process pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Switching delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Electronic insert FEL54 (AC/DC with relay output). . .9

Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Output signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Signal on alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Connectable load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Electronic insert FEL55 (8/16 mA) . . . . . . . . . . . . . . 10

Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Output signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Signal on alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Connectable load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Electronic insert FEL56 (NAMUR L-H edge). . . . . . . 11

Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Output signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Signal on alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Connectable load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Electronic insert FEL58 (NAMUR H-L edge). . . . . . . 12

Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Output signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Signal on alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Connectable load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Examples of mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Ambient temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Ambient temperature limits . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Storage temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Installation height as per IEC61010-1 Ed.3 . . . . . . . . . . . . . . 20

Climate class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Degree of protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Vibration resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Electromagnetic compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Process conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Process temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Thermal shock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Process pressure pe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Test pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

State of aggregation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Viscosity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Solids content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Lateral loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Medium conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

2

Mechanical construction . . . . . . . . . . . . . . . . . . . . . . . 22

Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Process connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Operability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Electronic inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Operating concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Certificates and approvals . . . . . . . . . . . . . . . . . . . . . . 28

CE mark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

RoHS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

RCM-tick mark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Other certificates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

EAC conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

CRN approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Process seal according to ANSI/ISA 12.27.01 . . . . . . . . . . . . . 29

Pressure Equipment Directive 2014/68/EU (PED) . . . . . . . . . 29

Use in hazardous zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

ASME B 31.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Combinations of housing and electronic inserts . . . . . . . . . . . 30

Liquiphant S FTL70, 71

Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Ordering information Liquiphant S FTL70, FTL71 . . . . . . . . . 31

Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Lap joint flange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Lap joint flanges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Weather protection cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Sliding sleeves for unpressurized operation . . . . . . . . . . . . . . . 35

High pressure sliding sleeves . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Cover with sight glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Cover with sight glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Technical Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Functional safety (SIL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Safety Instructions (ATEX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Safety Instructions (NEPSI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Control Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3

Liquiphant S FTL70, 71

FEL51/52/54

…

FEL55/56/57/58/50A

Ex i

…

E

X

E

X

Switching unit
PLC
Isolating
amplifier
Segment
coupler

Application

Point level detection Maximum or minimum detection in tanks or pipes with all types of cold to very hot liquids. The devices

are also suitable for use in hazardous areas and for applications involving high pressure.

L00-FTL7xxxx-11-05-xx-xx-001

Function and system design

Measuring principle The sensor's fork vibrates at its intrinsic frequency. This frequency is reduced when covered with liquid.

This change in frequency causes the point level switch to switch.

Modularity

Point level switch

Liquiphant S FTL7x with electronic inserts
FEL51, FEL52, FEL54

L00-FTL7xxxx-15-05-xx-xx-000

Point level switch

Liquiphant S FTL7x with electronic inserts
FEL55, FEL56, FEL57, FEL58, FEL50A
for connecting to a separate switching unit,
an isolating amplifier or for connecting
to a PROFIBUS PA segment coupler

4

L00-FTL7xxxx-15-05-xx-en-000

Liquiphant S FTL70, 71

Electronic versions FEL51:

Two-wire AC version;
Switches the load directly into the power supply circuit via an electronic switch.

FEL52:
Three-wire DC version;
Switches the load via the transistor (PNP) and separate connection e.g. in conjunction with
programmable logic controllers (PLCs), DI modules as per EN 61131-2.

FEL54:
Universal current version with relay output;
Switches the loads via 2 floating change-over contacts.

FEL55:
Signal transmission 16/8 mA on two-wire cabling e.g. in conjunction with programmable logic
controllers (PLCs), AI modules 4 to 20 mA as per EN 61131-2.

FEL56:
For separate switching unit; signal transmission L-H edge 0.6 to 1.0 / 2.2 to 2.8 mA
to EN 50227 (NAMUR) on two-wire cabling.

FEL58:
For separate switching unit; signal transmission H-L edge 2.2 to 3.5 / 0.6 to 1.0 mA
to EN 50227 (NAMUR) on two-wire cabling.
Checking of connecting cabling and other devices by pressing a key on the electronic insert.

FEL57:
For separate switching unit; PFM signal transmission;
Current pulses superposed on the power supply along the two-wire cabling.
Proof test from the switching unit without changing levels.

FEL50A:
For connecting to PROFIBUS PA;
Cyclic and acyclic data exchange acc. to PROFIBUS-PA Profile 3.0
Discrete Input

Galvanic isolation FEL51, FEL52, FEL50A: between sensor and power supply

FEL54: between sensor and power supply and load

FEL55, FEL56, FEL57, FEL58, FEL50D: see connected switching unit

Design FTL70: Compact

FTL71: With extension pipe

Input

Measured variable Level (limit value)

Measuring range (detection range)

Process density Setting on the electronic insert > 0.5 g/cm

FTL70: dependent on mounting point

FTL71: dependent on mounting point and the extension pipe ordered.
Standard extension pipe up to 3 m (9.8 ft) and up to 6 m (20 ft) on request.



(SGU) or > 0.7 g/cm (SGU) (others on request)

5

Electronic insert FEL51 (AC 2-wire)

L1

U~ max. 253 V AC

50/60 Hz

NNPE

(Ground)

1A

min.
19 V

12

FEL51

*

R

*

External load R

be connectedmust

MAX

MIN

Power supply Supply voltage: AC 19 to 253 V

Power consumption: < 0.83 W
Residual current consumption: < 3.8 mA
Short-circuit protection
Overvoltage protection FEL51: overvoltage category III

Electrical connection Two-wire AC connection

Switches the load directly into the power supply
circuit via an electronic switch.

Always connect in series with a load!

Check the following:

• The residual current in blocked state
(up to 3.8 mA)

• That for low voltage
– the voltage drop across the load is such that

the minimum terminal voltage at the
electronic insert (19 V)
when blocked is not undershot.

– the voltage drop across the electronics when

switched through is observed (up to 12 V)

• That a relay cannot de-energize with holding
power below 3.8 mA.
If this is the case, a resistor should be
connected parallel to the relay. An RC module is
available under the part number: 71107226

• When selecting the relay, pay attention to the
holding power
/ rated power
(see "Connectable load")

Liquiphant S FTL70, 71

L00-FTL5xxxx-04-05-xx-en-007

Output signal

I

L

= load current

Safety mode Level Output signal LEDs

(switched through)

< 3.8 mA

= residual current

(blocked)

= lit

L00-FTL2xxxx-07-05-

Signal on alarm Output signal on power failure or in the event of damaged sensor: < 3.8 mA

Connectable load • Voltage drop via FEL51

• Residual current if electrical switch is blocked:

• Load switched directly into the power supply circuit via the thyristor.
Transient (40 ms)

The load is switched via an electronic switch directly in the power circuit.

= unlit

xx-xx-000

12 V

 3.8 mA

 1.5 A,  375 VA at 253 V or  36 VA at 24 V (not short-circuit-proof)

Always connect in series with a load!
Not suitable for connection to low-voltage PLC inputs!

green red

L00-FTL5xxxx-04-05-xx-xx-001

6

Liquiphant S FTL70, 71

2.7

2.5

2.3

2.1

1.9

1.7

1.5

1.3

1.1

0.9

0.7

0.5
20 24 27 43 48 53 60 110 121 207 230 253

P/S

U

P1

Selection guide for relays

TI00328F_001

Minimum nominal power of load
P/S nominal power in [W] / [VA]
U operating voltage in [V]

Position Operating voltage Nominal power

min. max.

P1
AC operation

24 V
110 V
230 V

> 1.3 VA
> 1.5 VA
> 2.5 VA

< 8.4 VA
< 38.5 VA
< 80.5 VA

Relays with less nominal power can be operated via an RC module connected in parallel (optional).

7

Electronic insert FEL52 (DC PNP)

1 2 3

(+)

FEL52

L+

L–

–

0.5 A

U– 10…55 V DC

...

Relais,
PLC, ...

PE

(Ground)

R

MAX

MIN

L+ +

1 3

L+ +

1 3

1 3

1 3

I

L

I

L

< 100 μA

< 100 μA

Power supply Supply voltage: DC 10 to 55 V

 1.7 V, 0 to 400 Hz

Ripple:
Current consumption:  15 mA
Power consumption:  0.83 W
Reverse polarity protection
Overvoltage protection FEL52: overvoltage category III

Electrical connection Three-wire DC connection

Switches the load via the transistor (PNP) and
separate connection.
Preferably used with programmable logic
controllers (PLC),
DI modules as per EN 61131-2.
Positive signal at switching output of the
electronics (PNP); Output blocked on reaching
point level.

Liquiphant S FTL70, 71

Output signal

I

L

= load current

Safety mode Level Output signal LEDs

(switched through)

< 100 μA

= residual current

(blocked)

= lit

= unlit

L00-FTL2xxxx-07-05-

xx-xx-000

Signal on alarm Output signal on power failure or in the event of damaged sensor: < 100 μA

Connectable load • Load switched via transistor and separate PNP connection,

•Load current

 DC 55 V

 350 mA (pulsed overload and short-circuit protection)

• Residual current < 100 μA (with transistor blocked)

• Capacitance load  0.5 μF at 55 V, 1.0 μF at 24 V

8

• Residual voltage < 3 V (with transistor switched through);

L00-FTL5xxxx-04-05-xx-xx-030

green red

L00-FTL5xxxx-04-05-xx-xx-004

Liquiphant S FTL70, 71

L1
L+

a

NO

a

NO

u

C

u

C

N

L–

r

NC

r

NC

0.5 A

PE

(Ground)

*

** **

12 678345

FEL54

U~ 19…253 V AC, 50/60 Hz
U– 19… 55 V DC

...

MAX

MIN

354

354

687

687

354

354

687

687

Electronic insert FEL54 (AC/DC with relay output)

Power supply Supply voltage: AC 19 to 253 V, 50/60 Hz or DC 19 to 55 V

Power consumption:
Reverse polarity protection
Overvoltage protection FEL54: overvoltage category III

Electrical connection Universal current connection with relay output

Power supply:
Please note the different
voltage ranges for AC and DC.

Output:
When connecting an instrument with
high inductance, provide a spark arrester
to protect the relay contact.
A fine-wire fuse (depending on the
load connected) protects the relay
contact on short-circuiting.
Both relay contacts switch simultaneously.

 1.3 W

Output signal

* When jumpered, the relay
output works with NPN logic.

** See "Connectable load"

= relay energized

= relay de-energized

= lit

= unlit

L00-FTL2xxxx-07-05-

xx-xx-001

L00-FTL5xxxx-04-05-xx-xx-002

Safety mode Level Output signal LEDs

green red

L00-FTL5xxxx-04-05-xx-xx-005

Signal on alarm Output signal on power failure or in the event of damaged sensor: relay de-energized

Connectable load • Loads switched via 2 floating change-over contacts (DPDT).

 6 A (Ex de 4 A), U~  AC 253 V; P~  1500 VA, cos  = 1, P~  750 VA, cos  > 0.7

•I~

 6 A (Ex de 4 A) to DC 30 V , I%  0.2 A to 125 V

•I%

• When connecting a low-voltage circuit with double insulation according to IEC 1010, the following
applies: the sum of the voltages of the relay output and power supply is  300 V

• The electronic insert FEL52 DC-PNP is preferred for low DC load currents (e.g. when connecting to
a PLC)

• Relay contact material: silver/nickel AgNi 90/10

9

Electronic insert FEL55 (8/16 mA)

1 2

FEL55

–

Ex ia

+

E

X

E

X

U 11...36 V DC

–

+

–

+

R

R =

max

U–11 V

16.8 mA

PLC/SPS,
AI-Modules, ...

F=T50mA

MMAX

MIN

+
2 1

+
2 1

+
2 1

+
2 1

~16 mA

~8 mA

~8 mA

~16 mA

Power supply Supply voltage: DC 11 to 36 V

Power consumption: < 600 mW
Reverse polarity protection
Overvoltage protection FEL55: overvoltage category III

Electrical connection Two-wire connection for separate switching unit

For separate switching unit.
Signal transmission 16/8 mA on two-wire cabling.
For connection to programmable logic controllers
(PLC) for example, AI modules 4 to 20 mA to
EN 61131-2.
Output signal jump from high to low current on
point level.

Fuse required for non-Ex applications!
Only use power units with safe galvanic isolation (e.g.
SELV).

Liquiphant S FTL70, 71

Output signal

~ 16 mA

~8 mA

= 16 mA ± 5 %

= 8 mA ± 6 %

Safety mode Level Output signal LEDs

= lit

= unlit

L00-FTL2xxxx-07-05-

xx-xx-000

Signal on alarm Output signal on power failure or in the event of damaged sensor: < 3.6 mA

Connectable load • R = (U - 11 V) : 16.8 mA

• U = connection voltage: DC 11 to 36 V (in wet environments DC 11 to 35 V)

Example: PLC with 250  with 2-wire version

250  = (U – 11V) / 16.8 mA

4.2 [/] = U – 11 V
U = 15.2 V

L00-FTL5xxxx-04-05-xx-en-000

green red

L00-FTL5xxxx-04-05-xx-xx-006

10

Liquiphant S FTL70, 71

12

FEL56

–

EEx ia

H

L

+

E

X

E

X

I

Isolating amplifier
to
(NAMUR)

IEC 60947-5-6

MAX

MIN

+
2 1

+
2 1

+
2 1

+
2 1

0.6 …

1.0 mA

0.6 …

1.0 mA

2.2 …

2.8 mA

2.2 …

2.8 mA

Electronic insert FEL56 (NAMUR L-H edge)

Power supply Supply voltage: DC 8.2 V ±20 %

Power consumption: < 6 mW at I < 1 mA; < 38 mW at I = 2.8 mA
Connection data interface: IEC 60947-5-6

Electrical connection Two-wire connection for separate switching unit

For connecting to isolating amplifiers according to
NAMUR (IEC 60947-5-6), e.g. FTL325N from
Endress+Hauser.
Output signal jump from low to high current on
point level.

(L–H edge)

Connecting to multiplexer:
Set clock time to min. 2 s.

Output signal

Safety mode Level Output signal LEDs

= lit

= flashes

= unlit

L00-FTL5xxxx-07-05-

xx-xx-002

Signal on alarm Output signal in the event of damaged sensor: > 2.2 mA

Connectable load • See Technical Data of the isolating amplifier connected according to IEC 60947–5–6 (NAMUR)

L00-FTL5xxxx-04-05-xx-en-004

green red

L00-FTL5xxxx-04-05-xx-xx-003

11

Electronic insert FEL58 (NAMUR H-L edge)

12

FEL58

–

EEx ia

H

L

+

E

X

E

X

I

Isolating amplifier
to
(NAMUR)

IEC 60947-5-6

MAX

MIN

+
2 1

+
2 1

+
2 1

+
2 1

2.2 …

3.5 mA

2.2 …

3.5 mA

0.6 …

1.0 mA

0.6 …

1.0 mA

Power supply Supply voltage: DC 8.2 V ±20 %

Power consumption: < 6 mW at I < 1 mA; < 38 mW at I = 3.5 mA
Connection data interface: IEC 60947-5-6

Electrical connection Two-wire connection for separate switching unit

For connecting to isolating amplifiers
as per NAMUR (IEC 60947-5-6), e.g. FTL325N,
FTL375N from Endress+Hauser.
Output signal jump from high to low current on
point level.

(H–L edge)

Additional function:
Test key on the electronic insert.
Pressing the key breaks the connection to the
isolating amplifier.

Note!

!

In Ex–d applications, the additional function
can only be used if the housing is not exposed
to an explosive atmosphere.

Liquiphant S FTL70, 71

Output signal

Connecting to multiplexer:
Set clock time to min. 2 s.

= lit

= flashes

= unlit

L00-FTL5xxxx-07-05-

xx-xx-002

L00-FTL5xxxx-04-05-xx-en-002

Safety mode Level Output signal LEDs

green

yellow

L00-FTL5xxxx-04-05-xx-xx-007

Signal on alarm Output signal in the event of damaged sensor: < 1.0 mA

Connectable load • See Technical Data of the isolating amplifier connected according to IEC 60947–5–6 (NAMUR)

12

• Connection also to isolating amplifiers which have special safety circuits (I > 3.0 mA)