Endress+Hauser FTL51C Specifications

TI00347F/00/EN/14.18
71412981

Products Solutions Services

Technical Information

LiquiphantM
FTL51C

Vibronic

Point level switch for all kinds of liquids
with high corrosion-resistant coating

Application

The Liquiphant M is a point level switch for use in all liquids
– for temperatures of –50 °C to 150 °C (-58 to 302 °F)
– for pressure up to 40 bar (580 psi)
– for viscosities up to 10000 mm
– for densities of 0.5 g/cm (SGU) or 0.7 g/cm(SGU)

The device functions reliably regardless of flow, turbulence, bubbles, foam, vibration,
solids content or buildup, making the Liquiphant an ideal substitute for float switches.

All the wetted parts of the sensor (process connection, extension pipe and tuning fork)
are coated in enamel or various synthetic materials, making the point level switch
suitable for applications in very aggressive liquids.

International approvals certify use in hazardous areas.

Your benefits

• Use in safety systems requiring functional safety to SIL2/SIL3 in accordance with
IEC 61508/IEC 61511-1

• Optimally adapted to the process with a wide range of materials for corrosion­resistant coating

• Large number of process connections to choose from
– Flanges for various standards
– Universal usage

• No adjustment: quick, low-cost startup

• No mechanically moving parts: no maintenance, no wear, long operating life

• FDA-approved material (PFA Edlon)



/s (cSt)

Table of contents

Liquiphant M FTL51C

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

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

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

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

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

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

Electronic version for density measurement . . . . . . . . . . . . . . . 5

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

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

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

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

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

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 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

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

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

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

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

Output signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Signal on alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Connectable load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Electronic insert FEL50A (PROFIBUS PA) . . . . . . . . . 14

Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Output signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Signal on alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Electronic insert FEL50D (density). . . . . . . . . . . . . . . 16

Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

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

Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Operating principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Light signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Connection and function . . . . . . . . . . . . . . . . . . . . . . . 18

Connecting cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Safety mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Switching time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Switch-on behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Performance characteristics . . . . . . . . . . . . . . . . . . . . 18

Reference operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . 18

Maximum measured error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Repeatability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Influence of medium temperature . . . . . . . . . . . . . . . . . . . . . . . 18

Influence of medium density . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Influence of medium pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Switching delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Installation instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Examples of mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

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

Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Ambient temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Storage temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Operating altitude as per IEC61010-1 Ed.3 . . . . . . . . . . . . . . . 22

Climate class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Degree of protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Vibration resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Electromagnetic compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Medium conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Medium temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Thermal shock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2 Endress+Hauser

Medium pressure pe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Test pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Pressure shock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

State of aggregation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Viscosity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Solids content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Lateral loading capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Mechanical construction . . . . . . . . . . . . . . . . . . . . . . . 24

Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Process connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Human interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Electronic inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Operating concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Certificates and approvals . . . . . . . . . . . . . . . . . . . . . . 30

Certificates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

CE mark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

RoHS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

RCM-tick mark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

EAC conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

CRN approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Pressure Equipment Directive 2014/68/EU (PED) . . . . . . . . . 31

Process seal according to ANSI/ISA 12.27.01 . . . . . . . . . . . . . 31

Other certificates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Manufacturer declarations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Use in hazardous zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Liquiphant M FTL51C

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

Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Transparent cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Cover with sight glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Weather protection cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Technical Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Functional safety (SIL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Safety Instructions (ATEX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Safety Instructions (NEPSI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Control Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

3 Endress+Hauser

Liquiphant M FTL51C

FEL51/52/54

…

FEL55/56/57/58/50A

Ex i

-

.

1

Application

Point level detection Maximum or minimum detection in tanks or pipes containing all kinds of liquids, including use in

hazardous areas. Particularly suitable for very aggressive liquids thanks to high level of corrosion
protection.

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 M FTL with electronic versions
FEL51, FEL52, FEL54

Point level switch

Liquiphant M FTL with electronic versions
FEL55, FEL56, FEL57, FEL58
for connecting to a separate switching unit
or an isolating amplifier FEL50A
for connecting to a PROFIBUS PA segment

4 Endress+Hauser

1 = Switching unit, PLC, isolating amplifier, segment coupler

Liquiphant M FTL51C

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.
Connection cabling and slave devices tested by pressing a key on the electronic insert.

FEL57:
For separate switching unit; PFM signal transmission;
Current pulses superimposed on the power supply along the two-wire cabling.
Proof testing 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.

Electronic version for density measurement

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

Design FTL51C: flange, extension pipe and tuning fork are coated.

FEL50D:
For connecting to Density Computer FML621

FEL54: between sensor and power supply and load

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

Input

Measured variable Level (limit value)

Measuring range (detection range)

Density Setting on the electronic insert > 0.5 g/cm

Depends on the mounting point or the length of the sensor with extension pipe.
Up to 3000 mm (118 in) for synthetic coating, up to 1200 mm (47.2 in) for enamel coating



or > 0.7 g/cm (other on request)

Endress+Hauser 5

Electronic insert FEL51 (AC 2-wire)

L1
U~ 253 V AC≤

50/60 Hz

1A

min.

19 V

FEL51

!

1 2

1

R

N

PE

N

1

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 M FTL51C

1 = External load must be connected.

Output signal

I

L

= load current

Safety mode Level Output signal LEDs

(switched through)

< 3.8 mA

= 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: < 3.8 mA

Connectable load • Voltage drop via FEL51

• Residual current if electrical switch is blocked:

12 V

 3.8 mA

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

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

green red

6 Endress+Hauser

Liquiphant M FTL51C

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

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).

Endress+Hauser 7

Electronic insert FEL52 (DC PNP)

1 2 3

(+)

FEL52

L+

L–

–

0.5 A

U– 10…55 V DC

...

PE

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 the switch output of the electronics (PNP);
output blocked when point level is reached.

Liquiphant M FTL51C

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 the transistor and separate PNP connection,

•Load current

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

• Residual current < 100 μA (with transistor blocked)

• Capacitance load

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

 0.5 μF at 55 V,  1.0 μF at 24 V

R = Relay, PLC, ...

green red

 DC 55 V

8 Endress+Hauser

Liquiphant M FTL51C

L1
L+

a

NO

a

NO

u

C

u

C

N

L–

r

NC

r

NC

0.5 A

PE

1 2 6 7 83 4 5

FEL54

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

...

1

22

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
on short-circuiting.
Both relay contacts switch simultaneously.

 1.3 W

Output signal

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)

Endress+Hauser 9

1 = When jumpered, the relay output works with NPN logic.
2 = See below: "Connectable load"

Safety mode Level Output signal LEDs

green red

= relay energized

= relay de-energized

= lit

= unlit

L00-FTL2xxxx-07-05-

xx-xx-001

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

•I~

•I%

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

• 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

Electronic insert FEL55 (8/16 mA)

1 2

FEL55

–

Ex ia

+

U 11...36 V DC

–

+

–

+

R

R =

max

U – 11 V

16.8 mA

1

2

-

.

MIN

+
2 1

+
2 1

+
2 1

+
2 1

~16 mA

~8 mA

~8 mA

~16 mA

MAX

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 M FTL51C

1 = F = T 50 mA

2 = PLC, AI modules,...

Output signal

~ 16 mA

~ 8 mA

L00-FTL2xxxx-07-05-

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

= 16 mA ± 5 %

= 8 mA ± 6 %

= lit

= unlit

xx-xx-000

Safety mode Level Output signal LEDs

green red

10 Endress+Hauser

Liquiphant M FTL51C

1 2

FEL56

EEx ia

H

L

I

-

.

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 connection 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

= 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)

Safety mode Level Output signal LEDs

green red

Endress+Hauser 11

Electronic insert FEL58 (NAMUR H-L edge)

1 2

FEL58

EEx ia

H

L

I

-

.

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 connection to isolating amplifiers according to 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 M FTL51C

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

Output signal

= lit

= flashes

= unlit

L00-FTL5xxxx-07-05-

xx-xx-002

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

Safety mode Level Output signal LEDs

green yellow

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

12 Endress+Hauser

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

Liquiphant M FTL51C

–+

7 8

33 34

37 38

d4 d2

z6 d6

z4 z2

PFM

50 /

150 Hz

1 2

FEL57

EEx ia

Nivotester
FTL320
FTL325P 1CH
FTL325P 3CH

FTL370/372
FTL375P 1CH
Input 1

FTL372
FTL375P 2CH
Input 2

FTL375P 3CH
Input 3

-

.

150 Hz

50 Hz

Electronic insert FEL57 (PFM)

Power supply Supply voltage: DC 9.5 to 12.5 V

Current consumption: 10 to 13 mA
Power consumption: < 150 mW
Reverse polarity protection

Electrical connection Two-wire connection for separate switching unit

For connecting to Endress+Hauser switching units
Nivotester FTL320, FTL325P, FTL370, FTL372, FTL375P
(also with proof test).

Output signal jump of the PFM signal from high to
low frequency when sensor is covered. Switching between
minimum/maximum safety in the Nivotester.

Additional function “Proof testing”:
Following an interruption in the power supply, a test cycle
is activated, which tests the sensor and electronics without
any change in level.

Output signal

Approved for overfill prevention acc. to WHG (German
Water Resources Act).

The following can be switched at the electronic insert:

– Standard (STD):

Simulation approx. 8 s
tuning fork exposed – covered – exposed.
For proof testing, the Nivotester tests the sensor's level
notification function.

– Extended (EXT):

Simulation approx. 41 s: tuning fork exposed – covered –
alarm – exposed.
For proof testing, the Nivotester tests the sensor's level
notification function and fault notification (alarm)
function.

The check is activated and monitored at the switching unit.

The twin-core connecting cable (instrument cable) with a cable resistance of
connected to the screw terminals (conductor cross-sections 0.5 to 2.5 mm / 0.02 to 0.1 in) in the
connection compartment. Protective circuits against reverse polarity, HF influences and overvoltage
peaks are installed.
A shielded connecting cable is recommended in the event of strong electromagnetic interference. Here
the shielding must be connected to the sensor and the power supply. Maximum cable length up to
1000 m (3281 ft).

Safety mode Level Output signal

(PFM)

 25 per core is

LEDs

green yellow

Signal on alarm Output signal on power failure or in the event of damaged sensor: 0 Hz

Connectable load • Floating relay contacts in the connected switching unit Nivotester FTL325P, FTL375P

Endress+Hauser 13

L00-FTL2xxxx-07-05-

• For contact load, see the Technical Data of the switching unit.

= lit

= unlit

xx-xx-000

Electronic insert FEL50A (PROFIBUS PA)

PA– PA+

PROFIBUS PA

–

–

–

–

U– 9…32 V DC

...

1 2

FEL50A

-

.

PLC

PROFIBUS DP

PROFIBUS PA

PC

Proficard Profiboard

/

Segment coupler

-

.

Power supply Bus voltage: DC 9 to 32 V

Bus current:

• 12.5 mA +/– 1.0 mA (software version: 01.03.00, hardware version: 02.00)

• 10.5 mA +/– 1.0 mA (software version: 01.03.00, hardware version: 01.00)

Electrical connection Two-wire connection for power supply and data transfer

For connecting to PROFIBUS PA

Additional functions:

– Digital communication enables the representation, reading

and editing of the following parameters:
Fork frequency, switch-on frequency,
switch-off frequency, switch-on time and
switch-off time, status, measured value,

density change
– Matrix locking possible
– Switch to WHG mode possible

(WHG approval)
– For a detailed description, see BA00198F

Liquiphant M FTL51C

1 = Segment coupler

14 Endress+Hauser

Liquiphant M FTL51C

Output signal

Setting Level LEDs

not
inverted

= lit inverted

= unlit

L00-FTL2xxxx-07-05-

xx-xx-000

Signal on alarm Failure information can be accessed using the following interfaces:

• Yellow LED flashing,

• Status code

•Diagnostic code

FEL50A

green yellow

OUT_D = 0
PA bus signal

OUT_D = 1
PA bus signal

OUT_D = 0
PA bus signal

OUT_D = 1
PA bus signal

Endress+Hauser 15

Electronic insert FEL50D (density)

–+

10 82

112 182

1 2

FEL50D

EEx ia

FML621

–

+

1

-

.

Power supply Frequency range: 300 to 1500 Hz

Signal level: 4 mA
Pulse height: 16 mA
Pulse width: 20 μS

Liquiphant M FTL51C

Electrical connection

Two-wire connection at Density Computer FML621

For connecting to the Density and Concentration
Computer FML621.

The output signal is based on pulse technology.
With the aid of this signal, the fork frequency is
constantly forwarded to the switching unit.

Caution!

"

Operation with other switching units,
such as FTL325P, is not permitted.

This electronic insert cannot be installed in devices
that were originally used as a point level switch.

1 = Pulse

Signal on alarm Output signal on power failure or in the event of damaged sensor: 0 Hz

Adjustment In the Liquiphant M modular system, the option of an adjustment is also provided in addition to the

electronics (see feature 60: "Accessories").

There are three types of adjustment:

Standard adjustment (see ordering information for additional options, basic version A)

• Here, two fork parameters are determined to describe the sensor characteristics,

indicated in the adjustment report and provided with the product.

These parameters must be transferred to the Density Computer FML621.

Special adjustment (see ordering information for additional options, special adjustment,
density H

• Here, three fork parameters are determined to describe the sensor characteristics, indicated in the

adjustment report and provided with the product.

These parameters must be transferred to the Density Computer FML621.

Greater accuracy is achieved with this type of adjustment (see also "Performance characteristics").

Field adjustment

• During field adjustment, a density value actually determined by the customer is entered and the

system is automatically adjusted to this value (wet adjustment).

Note!
More information on Liquiphant M Density is available in Technical Information TI00420F. This
document is available for download at www.endress.com => Download.

O (K) or special adjustment, density H2O with 3.1 certificate (L))

2

!

16 Endress+Hauser

Liquiphant M FTL51C

PLC/SPS

PLC/SPS

FML621

FML621

1

2

3

4

-

.

Operating principle Measuring the density of a liquid medium in pipes and tanks. Also suitable for use in hazardous areas,

and preferably for applications in the chemical and food industry.

Light signals

* Pressure and temperature information required depending on the application.

1. Liquiphant M sensor with electronic insert FEL50D (pulse output);

2. Temperature sensor (e.g. 4 to 20 mA output);

3. Pressure transmitter (4 to 20 mA output);

4. Liquiphant Density and Concentration Computer FML621 with display and operating unit

LED Symbol Information

Yellow Measurement valid

Green Power on

Red No fault

Unstable process situation

Maintenance required

Power off

Maintenance required

Device failure

Endress+Hauser 17

Connection and function

13

(0.51)

*

Liquiphant M FTL51C

Connecting cables • Electronic inserts: cross-section  2.5 mm (14 AWG); strand in ferrule as per DIN 46228

• Protective ground in housing: cross-section

• External equipotential bonding connection on housing: cross-section  4 mm(12 AWG)

Safety mode Minimum/maximum residual current safety selectable on electronic insert

(with FEL57 on Nivotester only)

MAX = maximum safety:
The output switches to the power fail response when the fork is covered
For use with overfill prevention for example

MIN = minimum safety:
The output switches to the power fail response when the fork is exposed
For use with dry running protection for example

Switching time When fork is covered: approx. 0.5 s

When fork is exposed: approx. 1.0 s
Additionally configurable for PROFIBUS PA: 0.5 to 60 s

Other switching times available on request.

Switch-on behavior When switching on the power supply, the output assumes the alarm signal.

 3 s it assumes the correct switching mode (exception: FEL57)

After

 2.5 mm



(14 AWG)

Performance characteristics

Reference operating conditions

Maximum measured error Under reference operating conditions: max. +/–1 mm (0.04 in)

Repeatability 0.1 mm (0.004 in)

Hysteresis ECTFE and PFA: approx. 2 mm (0.08 in)

Influence of medium temperature

Influence of medium density max. +4.8 mm to –3.5 mm ((0.5 to 1.5 g/cm

Influence of medium pressure ECTFE and PFA:

Ambient temperature: 23 °C (73 °F)

Medium temperature: 23 °C (73 °F)



Medium density (water): 1 g/cm

Medium viscosity: 1 mm/s (cSt)

Medium pressure p

Sensor mounting: vertical from above

Density switch: to > 0.7 g/cm³ (SGU)

Enamel: approx. 2.5 mm (0.1 in)

ECTFE and PFA: max. +1.4 mm to –2.8 mm (–50 to +120 °C / -58 to 248 °F)
Enamel: max. +0.6 mm to –1.5 mm (–50 to +150 °C / -58 to 302 °F)

max. +0.19 in to -0.14 in

max. 0 mm to –2.0 mm (0 bar to 40 bar)
max. 0 in to -0.08 in (0 psi to 580 psi)
Enamel:
max. 0 mm to –1.0 mm (0 bar to 25 bar)
max. 0 in to -0.04 in (0 psi to 363 psi)

: 0 bar (0 psi)

e

(SGU)

* Switch point under reference operating conditions



(SGU))

Switching delay • When fork is covered: 0.5 s

18 Endress+Hauser

Liquiphant M FTL51C

13

(0.51)

4

(0.16)

4

( 0.16)

10

(0. )39

40

(. )1 57

46.5

13

(0.51)

4

(0.16)

4

( 0.16)

10

(0. )39

(. )1 83

• When fork is exposed: 1.0 s

• Available on request: 0.2 s; 1.5 s or 5 s (when the tuning fork is covered or exposed)

Operating conditions

Installation instructions

!

Switch points on the sensor depend on the mounting position, with reference to water,



density 1 g/cm

Note!

• The switch points of the Liquiphant M are at other positions to those of the previous version
Liquiphant II.

• Minimum distance between the tip of the fork and the tank wall or pipe wall: 10 mm

Synthetic coating:

Mounting from above Mounting from below Mounting from the side

Enamel coating:

(SGU), 23 °C (73 °F), pe 0 bar (0 psi).

Mounting from above Mounting from below Mounting from the side

Examples of mounting Examples of mounting depending on the viscosity  of the liquid and the tendency to form buildup

Optimum mounting, problem-free even with high viscosity:

Vertical from above Flush-mounted from the side

Endress+Hauser 19

Liquiphant M FTL51C

(≥ 1)

≥25

DN 40

Position the fork so that the narrow edge of the tines is vertical to ensure that the liquid can run off
easily.

With buildup on the tank walls:

* Ensure that there is sufficient distance between the buildup expected on the tank wall and the fork.

Vertical from above Protruding into the tank from the side

Mounting positions with low viscosity (up to 2000 mm/s):

Dimensions: mm (in)

* Deburr the nozzle surfaces

Mounting in piping from 2"

Flow velocities up to 5 m/s (16.4 ft/s) with a viscosity of 1 mm/s and density of 1 g/cm. (Check the
function in the case of other medium conditions.)

20 Endress+Hauser

Liquiphant M FTL51C

Support the device in the event of a severe dynamic load.

Support is possible only in conjunction with ECTFE or PFA synthetic coating.

Installation location

Ensure that there is adequate space outside the tank for mounting, connection and configuration.

Orientation FTL51C with short pipe up to approx. 500 (19.7 mm): any position

FTL51C with long pipe: vertical

Endress+Hauser 21

Liquiphant M FTL51C

T

a

T

p

70

(158)

T

a

50

(122)

0

(32)

*

100

(212)

150

(302)

T

p

90

(194)

-50

(-58)

**

-50

(-58)

0

(32)

50

(122)

°C (°F)

***

-40

(-40)

Environment

Ambient temperature range Permitted ambient temperature Ta at the housing depending on the medium temperature Tp in the

tank:

*

Additional temperature range for devices with a temperature spacer or pressure tight feed­through.

**

Maximum ambient temperature with FEL50D/FEL50A in hazardous areas.

***

For F16 housing, the following applies: -40 °C Ta +70 °C (-40 °F Ta +158 °F)

Storage temperature –50 to +80 °C (-58 to 176 °F)

Operating altitude as per IEC61010-1 Ed.3

Climate class Climate protection to IEC 68, Part 2-38,

Degree of protection

Vibration resistance As per IEC 68, parts 2-6 (10 to 55 Hz, 0.15 mm (0.01 in), 100 cycles)

Electromagnetic compatibility

Up to 2000 m (6600 ft) above sea level.

Can be extended up to 3000 m (9800 ft) above sea level if overvoltage protection is used, for example
HAW562 or HAW569.

Fig. 2a

Types of housing IP65 IP66* IP67* IP68* IP69 NEMA

Polyester housing F16 – X X – – 4X
Stainless steel housing F15 – X X – – 4X
Aluminum housing F17 – X X – – 4X
Aluminum housing F13**** – X – X*** – 4X/6P
Stainless steel housing F27 – X – X – 4X/6P
Aluminum housing T13

with separate connection compartment
(Ex d)

* As per EN60529
** As per NEMA 250
*** Only with M20 cable entry or G1/2 thread
**** F13 housing only in conjunction with XP or Ex d approval

Interference emission to EN 61326, Electrical Equipment Class B
Interference immunity to EN 61326; Annex A (Industrial) and NAMUR Recommendation NE 21
(EMC)

–X– X***–4X/6P

type**

22 Endress+Hauser

Liquiphant M FTL51C

Medium conditions

Medium temperature ECTFE: –50 °C to +120 °C (–58 °F to +248 °F)

PFA: –50 °C to +150 °C (–58 °F to +302 °F)
Enamel: max. –50 °C to +150 °C (–58 °F to +302 °F)

Thermal shock

Medium pressure p

Test pressure p

e

!

 120 °C/s (248 °F/s)

The following values apply over the entire temperature range. Pay attention to exceptions for flange
process connections!

• ECTFE and PFA: –1 to +40 bar (–14.5 to 580 psi)

• Enamel: max. –1 to +25 bar (–14.5 to 363 psi)

Please refer to the standards listed for the permitted pressure values of the flanges at higher
temperatures:

• pR EN 1092-1: 2005
With regard to its stability-temperature property, the material 1.4435 is identical to 1.4404, which
is classed under 13E0 in EN 1092-1 Tab. 18. The chemical composition of the two materials can be
identical.

• ASME B 16.5a - 1998 Tab. 2-2.2 F316

• ASME B 16.5a - 1998 Tab. 2.3.8 N10276

• JIS B 2220

The lowest value from the derating curves of the device and selected flange applies in each case.
Canadian CRN approval: Additional details on maximum pressure values are available in the download
area of the product page at "www.endress.com".

= 100 bar (1450 psi):

e

•  150 bar (2175 psi) or 1.5 times the medium pressure pe)

• Membrane burst pressure at 200 bar (2900 psi)

Note!
Device function is not available during pressure testing.

Pressure shock

State of aggregation Liquid

Density 0.7 g/cm

Viscosity  10,000 mm2/s (cSt)

Solids content

Lateral loading capacity  75 Nm

 20 bar/s ( 290 psi)

3

(SGU) = delivery status

0.5 g/cm

 ø5 mm (0.2 in)

3

(SGU) can be adjusted via switch

Endress+Hauser 23

Mechanical construction

R

*

!

Design Summary of all electrical and mechanical versions

Note!
2D and 3D drawings containing individual dimensions can be generated and downloaded in the
Configurator on the product pages of the Liquiphant FTL5x at www.endress.com.

Housing

Liquiphant M FTL51C

F16

Polyester (PBT)

F15

Stainless steel
(316L)

F17

Aluminum
Coated housing

F27
Stainless steel
(316L)

F13

Aluminum
(also for Ex d/XP),
coated housing

Plug-in electronic inserts to mount in the housing

FEL51:
FEL52:
FEL54:
FEL55:
FEL56:
FEL58:
FEL57:
FEL50A:
FEL50D:

Two-wire AC connection
Three-wire DC connection PNP
Universal current connection, 2 relay outputs
Output 16/8 mA for separate switching unit
Output 0.6 to 1.0 / 2.2 to 2.8 mA for separate switching unit (NAMUR)
Output 2.2 to 3.5 / 0.6 to 1.0 mA for separate switching unit (NAMUR)
Output 150/50 Hz, PFM, for separate switching unit (Nivotester)
Digital communication PROFIBUS PA
Pulse output for Density Computer FML621

Bushings

Temperature spacer and pressure-tight feedthrough: enables
closed tank insulation and normal ambient temperature for the
housing.

T13

Aluminum with separate
connection compartment
(also Ex de and Ex d),
coated housing

Process connections

Flanges* according to DIN/EN, ASME, JIS from DN 40 / 1½"
* The following applies for DN 25/ASME 1":
Radius (R)

 4 mm.

Take into account for counterflange!

Sensors

Length L Length L II
With extension pipe up to 3 m
or special "length L II" (see also Page 24)

24 Endress+Hauser

Liquiphant M FTL51C

ø85

(3.35)

£76

(2.99)

£20.6

£(0.81)

£155

(6.1)

*

ø76

(ø2.99)

£64

(2.52)

£150

(5.91)

*

A

B

*

ø80

(3.15)

£69

(2.72)

£173

(6.81)

£60

(2.36)

10

(0.39)

*

£65

(2.56)

£97

(3.82)

£190

( 7.48)£

Dimensions Dimensions in mm (in)!

Polyester housing F16

Stainless steel housing F15

1. = approx. 25 (0.98) ECTFE, PFA

2. = approx. 29 (1.14) enamel

Aluminum housing F17/F13
Stainless steel housing (316L) F27

Aluminum housing T13 with separate
connection compartment

Endress+Hauser 25

* This length is customer-specific.

!

Note!
The switch points of the Liquiphant M are at other positions to those of the previous version Liquiphant II.

Bushings: temperature spacer, pressure tight feed-through

1

+ 140

(5.51)

≥115

(≥4.53)

D

L

Temperature spacer

Provides sealed insulation for the vessel
and normal ambient temperatures for the
housing.

Pressure tight feed-through

Protects the housing from vessel pressures
up to 40 bar (580 psi) if the sensor is
damaged.
Provides sealed insulation for the vessel
and normal ambient temperatures for the
housing.

1. = Insulation

Process connections

Process connection Dimensions Accessories Pressure

Temperature

Flanges:

A#

Synthetic coating

ASME B16.5 (RF)
EN 1092-1 (Form A)
JIS B 2220 (RF)

Enamel coating

ASME B16.5 (RF)
EN 1092-1 (Form B)
JIS B 2220 (RF)

*) FDA-compliant material in accordance with 21 CFR Part 177.1550/2600

#
B#
#
C##
K#
#

For synthetic
coating:
seal made of PTFE
supplied

For enamel
coating:
Se al p rov ide d by the
customer

See nominal pressure
of flange, however

For ECTFE:

For PFA
(Edlon*):

For enamel:

Liquiphant M FTL51C



40 bar



120 °C

40 bar




150 °C

25 bar




150 °C

Sensor length L and pipe diameter D

The maximum diameter D depends on the
coating material.

Layer thickness
Coating material

Lower limit 0.5 mm 0.45 mm 0.45 mm 0.45 mm 0.4 mm

Upper limit 1.6 mm 1.6 mm 1.6 mm 1.6 mm 0.8 mm

Maximum diameter D 24.6 mm 24.6 mm 24.6 mm 24.6 mm 23 mm

ECTFE PFA*

(Edlon

TM

)

PFA
(RubyRed)

PFA
(conductive)

Enamel

Any length L:
148 mm to 3000 mm (6 in to 115 in) for synthetic coating
148 mm to 1200 mm (6 in to 48 in) for enamel coating

26 Endress+Hauser

Liquiphant M FTL51C

!

Note!
The switch points of the Liquiphant M are at other positions to those of the previous version
Liquiphant II.

Special length "L II": 115 mm (4.5 in)
If vertically mounted from above, the same switch point as for the Liquiphant II
FTL360, FTL365, FDL30, FDL35

Weights The typical total weight of the Liquiphant can be calculated by adding the weights of the individual

components to the basic weight.

Basic weight Weight in

The basic weight comprises:

• Sensor (compact)

• Electronic insert

• Polyester housing F16

• Housing cover

Housing kg (lbs)

Aluminum housing F13 (connection: NPT¾, G½ or M20) 0.5 (1.1)
Stainless steel housing F15 (connection: NPT½, G½, M20 or M12 connector) 0.1 (0.2)
Aluminum housing F17 (connection: NPT¾, G½, M20 or M12 connector) 0.5 (1.1)
Stainless steel housing F27 (connection: NPT½, G½ or M20) 0.3 (0.7)
Aluminum housing T13 with separate connection compartment (connection: NPT¾, G½ or

M20)

Temperature spacer kg (lbs)

1 pc 0.6 (1.3)

Pressure-tight feedthrough kg (lbs)

1 pc 0.7 (1.54)

Process connection: flanges ASME B16.5 kg (lbs)

NPS 1" Cl.150, 316/316L 1.0 (2.2)
NPS 1½" Cl.150, 316/316L 1.5 (3.3)
NPS 2" Cl.150, 316/316L 2.4 (5.3)
NPS 2" Cl.300, 316/316L 3.2 (7.1)
NPS 3" Cl.150, 316/316L 4.9 (10.8)
NPS 3" Cl.300, 316/316L 6.8 (15)
NPS 3" Cl.600, 316/316L 8.5 (18.7)
NPS 4" Cl.150, 316/316L 7.0 (15.4)

kg (lbs)

0.6 (1.32)

0.9 (2)

Process connection: flanges EN1092-1 (DIN2527) kg (lbs)

DN25 PN25/40, 316L 1.4 (3.1)
DN32 PN25/40, 316L 2.0 (4.4)
DN40 PN25/40, 316L 2.4 (5.3)
DN50 PN6, 316L 4.5 (9.9)
DN50 PN25/40, 316L 3.2 (7.1)
DN80 PN25/40, 316L 5.9 (13)
DN100 PN10/16, 316L 10.1 (22.3)
DN100 PN25/40, 316L 7.5 (16.5)

Process connection: flanges JIS B220 kg (lbs)

10K 50A, 316L 1.9 (4.2)

Pipe extension kg (lbs)

1 m 0.9 (2)
100 in 2.3 (5.1)

Weather protection cover kg (lbs)

1 pc 0.3 (0.7)

Endress+Hauser 27

Material Material specifications as per AISI and DIN-EN.

Parts in contact with process

• Extension pipe substrate Alloy C4 in the case of enamel coating: 316L (1.4435 or 1.4404) in the case

of synthetic coating

• Fork substrate Alloy C4 in the case of enamel coating: 316L (1.4435) in the case of synthetic coating

•Flanges, coated:

Liquiphant M FTL51C

Coating material ECTFE PFA*

Substrate 316L (1.4404) 316L (1.4404) 316L (1.4404) 316L (1.4404) 1.0487

* FDA-compliant in accordance with 21 CFR Part 177.1550

(Edlon

TM

)

PFA
(RubyRed)

PFA
(conductive)

Enamel

Parts with no process contact

• Tuning fork/housing seal: EPDM

• Temperature spacer: 316L (1.4435)

• Pressure-tight feedthrough: 316L (1.4435)

• Ground terminal on housing (external): 316L (1.4404)

• Cable glands

– Housing F13, F15, F16, F17: polyamide (PA)

In the case of approval B or C ( ä 31 Ordering information): nickel-plated brass
– Housing F27: polyamide PA, with approval "B" or "C" 316L (1.4435)
– Housing T13: nickel-plated brass

• Polyester housing F16: PBT-FR with PBT-FR cover or with PA12 transparent cover
– Cover seal: EPDM
– Nameplate glued: polyester film (PET)
– Pressure compensation filter: PBT-GF20

• Stainless steel housing F15: 316L (1.4404)
– Cover seal: silicone
– Safety claw: 304 (1.4301)
– Pressure compensation filter: PBT-GF20, PA

• Aluminum housing F17/F13: EN-AC-AlSi10Mg, plastic-coated
– Nameplate: aluminum, anodized
– Cover seal: EPDM
– Safety claw: nickel-plated brass
– Pressure compensation filter: silicone (F17 housing only)

• Stainless steel housing F27: 316L
– Nameplate: 316L (1.4404)
– Cover seal: FVMQ (optional: EPDM seal available as spare part)
– Safety claw: 316L (1.4435)

• Aluminum housing T13: EN-AC-AlSi10Mg, plastic-coated,
– Nameplate: aluminum, anodized
– Cover seal: EPDM
– Safety claw: nickel-plated brass

Process connections • Flanges made of 316L (1.4404) - synthetic coating; flanges made of 1.0487 (ASTMA 529) - enamel

coating

• Flanges as per EN/DIN 1092-1 from DN 25, as per ASME B16.5 from 1", as per JIS B 2220 (RF) from
10K50

28 Endress+Hauser

Liquiphant M FTL51C

Min

Max1

2

>0,7

>0,5

FEL51

1 2

L1 N U~

19...253V AC
50/60Hz

I max : 350mA

1

2

3

HW

OFF

ON

Address

SW

12345678

FEL50A

1 2

PA– PA +

2

3

–

FEL50D

+

GN

YE

RD

12

-

+

Impuls

Human interface

Electronic inserts

With FEL51, FEL52, FEL54, FEL55:

• 2 switches for safety mode and density change

• green LED to indicate operational status

• red LED to indicate the switching status,
flashes in the event of corrosion damage on sensor
or if the electronics are defective

With FEL56:

• 2 switches for safety mode and density change

• green LED flashes to indicate operational status

• red LED to indicate the switching status,
flashes in the event of corrosion damage on sensor
or if the electronics are defective

With FEL57:

• 2 switches for density change and proof testing

• green LED to indicate operational status

• yellow LED to indicate the covered status,
flashes in the event of corrosion damage on sensor
or if the electronics are defective

With FEL58:

• 2 switches for safety mode and density change

•green LED
– flashes quickly to indicate operational status,
– flashes slowly in the event of corrosion damage to the

sensor of if the electronics are defective

• yellow LED to indicate the switching status,
Test key – breaks the cable connection

1. = Terminals, 2. = light emitting diodes,

3. = switches

With FEL50A:

• 8 switches for configuring the device address

• green LED to indicate operational status,
pulsing to indicate communication;

• yellow LED to indicate the switching status,
flashes in the event of corrosion damage on sensor
or if the electronics are defective

With FEL50D:

• yellow LED: to indicate the validation of the
measurement

• green LED: to indicate the operational status

• red LED: to indicate faults

Operating concept Onsite configuration

1. = Terminals, 2. = light emitting diodes,

3. = switches

Endress+Hauser 29

Liquiphant M FTL51C

Certificates and approvals

Certificates See Ordering information  ä 31.

CE mark The measuring system meets the legal requirements of the applicable EC Directives. These are listed in

the corresponding EC Declaration of Conformity along with the standards applied.
Endress+Hauser confirms successful testing of the device by affixing to it the CE mark.

RoHS The measuring system complies with the substance restrictions of the EU Directive on the restriction

of the use of certain hazardous substances 2011/65/EU (RoHS 2).

RCM-tick mark The product or measuring system supplied complies with the regulations of the Australian

Communications and Media Authority (ACMA) for network integrity, performance characteristics and
health and safety requirements. The specifications for electromagnetic compatibility, in particular, are
observed. The products bear the RCM-tick mark on their nameplate.

A0029561

EAC conformity The measuring system meets the legal requirements of the applicable EAC Directives. These are listed

in the corresponding EAC Declaration of Conformity along with the standards applied.
Endress+Hauser confirms successful testing of the device by affixing to it the EAC mark.

CRN approval Device versions with a CRN approval (Canadian Registration Number) are listed in the following table.

Order code Process connection: flange ASME B16.5, > 316/316L

ACK 1½" 150 lbs ECTFE

ACL 1½" 150 lbs PFA (Edlon

ACM 1½" 150 lbs PFA (RubyRed)

ACN 1½" 150 lbs PFA (conductive)

AEK 2" 150 lbs ECTFE

AEL 2" 150 lbs PFA (Edlon

AEM 2" 150 lbs PFA (RubyRed)

AEN 2" 150 lbs PFA (conductive)

AES 2" 150 lbs Enamel

AFK 2" 300 lbs ECTFE

AFL 2" 300 lbs PFA (Edlon

AFM 2" 300 lbs PFA (RubyRed)

AFN 2" 300 lbs PFA (conductive)

AFS 2" 300 lbs Enamel

ALK 3" 150 lbs ECTFE

ALL 3" 150 lbs PFA (Edlon

ALM 3" 150 lbs PFA (RubyRed)

ALN 3" 150 lbs PFA (conductive)

APK 4" 150 lbs ECTFE

APL 4" 150 lbs PFA (Edlon

APM 4" 150 lbs PFA (RubyRed)

APN 4" 150 lbs PFA (conductive)

A8K 1" 150 lbs ECTFE

A8L 1" 150 lbs PFA (Edlon

A8M 1" 150 lbs PFA (RubyRed)

A8N 1" 150 lbs PFA (conductive)

YY9 Special version

TM

)

TM

)

TM

)

TM

)

TM

)

TM

)

The registration number CRN: 0F10904.5CADD1 is stamped on the nameplate of CRN-approved
devices.

30 Endress+Hauser

Liquiphant M FTL51C

Pressure Equipment Directive 2014/68/EU (PED)

Process seal according to ANSI/ISA 12.27.01

Other certificates • Material certificate as per EN 10204/3.1 for all pressure bearing parts

!

Pressure instruments with permitted pressure ≤ 200 bar (2 900 psi)

Pressure instruments with a flange and threaded boss that do not have a pressure-bearing housing do
not fall within the scope of the Pressure Equipment Directive, irrespective of the maximum permitted
pressure.

Reason:

According to Article 2, point 5 of EU Directive 2014/68/EU, pressure accessories are defined as
"devices with an operational function and having pressure-bearing housings".
If a pressure instrument does not have a pressure-bearing housing (no identifiable pressure chamber
of its own), there is no pressure accessory present within the meaning of the Directive.

Practice in North America for the installation of process seals.
Endress+Hauser devices are designed as either single seal or dual seal devices with an alarm in
accordance with ANSI/ISA 12.27.01. This means that the user does need to install, or bear the costs
of, an external secondary process seal in the thermowell which is required in ANSI/NFPA 70 (NEC) and
CSA 22.1 (CEC). These devices comply with installation practice in North America and enable very safe,
low-cost installation in pressurized applications with hazardous media.
Further information on the specific device can be found in the following section: Safety Instructions
(ATEX)  ä 34 ff.

Product Type Max. process pressure Marking Listing

Liquiphant M FTL51-S/T##...

FTL51-P/Q/R##...

• Leak detection system in conjunction with WHG approval
Approval number: Z–65.40–446 (see also "Ordering information" )

Note!
Device components in contact with the process are listed in the sections "Mechanical construction"
( ä 24 ff.) and "Ordering information" ( ä 31).

64/100 bar
(928/1450 psi)

Single Seal CSA

FM

Manufacturer declarations The following documents can be ordered together with the document, depending on the desired device

configuration:

•FDA conformity

The applicable European guidelines and standards can be found in the relevant EU Declarations of
Conformity.

Use in hazardous zones Pay particular attention to the information provided in the documentation: Safety Instructions, Control

Drawings etc.  ä 34

!

Note!
The use of the selected coating material affects the approved gas groups IIB/IIC. Please refer to the
information in the safety documentation XA  ä 34 ff.

Ordering information

Detailed ordering information is available:

• In the Product Configurator on the Endress+Hauser website: www.endress.com → Click "Corporate"
→ Select your country → Click "Products" → Select the product using the filter and search field → Open
the product page → The "Configuration" button on the right of the product picture opens the Product
Configurator.

• From your Endress+Hauser Sales Center: www.addresses.endress.com

!

Note!

Product Configurator - the tool for individual product configuration

• Up-to-the-minute configuration data

• Depending on the device: direct input of information specific to the measuring point, such as
measuring range or operating language

Endress+Hauser 31

Liquiphant M FTL51C

Ø110 (4.33)

114 (4.49)

140 (5.51)

140 (5.51)

• Automatic verification of exclusion criteria

• Automatic creation of the order code and its breakdown in PDF or Excel output format

• Ability to order directly in the Endress+Hauser Online Shop

Accessories

Transparent cover

Cover with sight glass

Weather protection cover For F16 housing

For polyester housing F16

Material: PA 12

Weight: 0.04 kg

Order number: 943461-0001

For stainless steel housing F15

Material: AISI 316L

Weight: 0.16 kg

– With glass sight glass

Order number: 943301-1000

– With PC sight glass

Order number: 52001403
(Not for CSA, General Purpose)

Material Order No. Weight

PBT, gray 71127760 240 g (8.46 oz)

For F13, F17 and F27 housing

32 Endress+Hauser

Liquiphant M FTL51C

102 (4.02)

162 (6.38)

112 (4.41)

Material Order No. Weight

PA6, gray 71040497 300 g (10.58 oz)

Documentation

!

Operating Instructions Electronic insert FEL50A for Liquiphant M/S PROFIBUS PA

Technical Information General instructions for electromagnetic compatibility

Note!
You can find supplementary documentation on the product pages at www.endress.com

BA00141F/00/en

Liquiphant M Density, Density Computer FML621
BA00335F/00/en

Liquiphant M FTL51C
KA00162F/00/a6

Liquiphant M FTL51C-######## 7 ##
KA00165F/00/a6

Liquiphant M Density FTL50, FTL51
Electronic insert: FEL50D
KA00284F/00/a6

Liquiphant M Density FTL50H, FTL51H
Electronic insert: FEL50D
KA00285F/00/a6

Liquiphant M Density FTL51C
Electronic insert: FEL50D
KA00286F/00/a6

(Test procedure, installation recommendation)
TI00241F/00/en

Liquiphant M FTL50/51(H), for process temperatures up to 150 °C
TI00328F/00/en

Isolating amplifier FTL325P, 1 or 3-channel switching units for DIN rail mounting
for Liquiphant M/S with electronic insert FEL57
TI350F/00/en

Isolating amplifier FTL325N, 1 or 3-channel switching units for DIN rail mounting
for Liquiphant M/S with electronic insert FEL56, FEL58
TI353F/00/en

Liquiphant S FTL70/71, for medium temperatures up to 280 °C
TI354F/00/en

Endress+Hauser 33

Isolating amplifier FTL375P, 1 to 3-channel switching units for DIN rail mounting
for Liquiphant M/S with electronic insert FEL57
TI360F/00/en

Liquiphant M Density, Density Computer FML621
TI420F/00/en

Weld-in adapter,
TI00426F

Functional safety (SIL) Liquiphant M with electronic insert FEL51 (MAX)

SD00164F

Liquiphant M with electronic insert FEL51 (MIN)
SD00185F

Liquiphant M with electronic insert FEL52 (MAX)
SD00163F

Liquiphant M with electronic insert FEL52 (MIN)
SD00186F

Liquiphant M with electronic insert FEL54 (MAX)
SD00162F

Liquiphant M with electronic insert FEL54 (MIN)
SD00187F

Liquiphant M with electronic insert FEL55 (MAX)
SD00167F

Liquiphant M with electronic insert FEL55 (MIN)
SD00279F

Liquiphant M with electronic insert FEL57 + Nivotester FTL325P
SD01508F (MAX + MIN)

Liquiphant M with electronic insert FEL56 + Nivotester FTL325N
SD01521F (MAX + MIN)

Liquiphant M with electronic insert FEL58 + Nivotester FTL325N
SD01522F (MAX + MIN)

Liquiphant M FTL51C

Safety Instructions (ATEX) 40II 1/2 G, Ex d IIC/B (KEMA 99 ATEX 1157)

XA00031F/00/a3

40II 1/2 G, Ex ia/ib IIC/B (KEMA 99 ATEX 0523)
XA00063F/00/a3

40II 1 G, Ex ia IIC/B (KEMA 99 ATEX 5172 X)
XA00064F/00/a3

40II 1/2 G, Ex de IIC/B (KEMA 00 ATEX 2035)
XA00108F/00/a3

40II 3 G, Ex nA/nC II (EG 01 007-a)
XA00182F/00/a3

Safety Instructions (NEPSI) Ex d IIC/IIB T3-T6 , Ex d IIC T2-T6

(NEPSI GYJ06424)
XA00401F/00/B2

Ex ia IIC T2-T6, Ex ia IIB T3-T6
(NEPSI GYJ05556, NEPSI GYJ06464),
XC00009F/00/b2

Ex nA II T3-T6, Ex nC/nL IIC T3-T6
(NEPSI GYJ04360, NEPSI GYJ071414)
XC00010F/00/b2

34 Endress+Hauser

Liquiphant M FTL51C

Control Drawings Liquiphant M (IS and NI) Current output PFM, NAMUR Entity installation

Class I, Div. 1, 2, Groups A, B, C, D
Class I, Zone 0
Class II, Div. 1, 2, Groups E, F, G
Class III
ZD00041F

Liquiphant M, Liquiphant S (cCSAus / IS)
Class I, Div. 1, Groups A, B, C, D Ex ia IIC T6
Class II, Div. 1, Groups E, F, G
Class III
ZD00042F

Liquiphant M (NI), FTL50(H), FTL51(H), FTL51C, FTL70, FTL71
Class I, Div. 2, Groups A, B, C, D
Class II, Div. 2, Groups F, G
Class III
ZD00043F

Liquiphant M, Liquiphant S (cCSAus / XP)
Class I, Groups A, B, C, D
Class II, Groups E, F, G
Class III
ZD00240F

Liquiphant M (IS and NI) PROFIBUS PA, FOUNDATION FieldbusClass I, Zone 0, IIC
Class I, Division 1, 2, Groups A, B, C, D
Class II, Division 1, 2, Groups E, F, G
Class III
ZD00244F

Endress+Hauser 35

www.addresses.endress.com

71412981