Endress+Hauser Nivotester FailSafe FTL825 User manual

BA01038F/00/EN/01.11
71148747
Operating Instructions
Nivotester FailSafe FTL825
Vibronic
With intrinsically safe signal circuit for point level switch
Liquiphant FailSafe FTL8x

Nivotester FailSafe FTL825 Table of contents
2Endress+Hauser
Table of contents
1 Important document information . . . . . 3
1.1 About this document . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Notes on safety conventions and icons . . . . . . . . . . 4
2 Basic safety instructions . . . . . . . . . . . . 5
2.1 Personnel requirements . . . . . . . . . . . . . . . . . . . . . 5
2.2 Designated use . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.3 Occupational safety . . . . . . . . . . . . . . . . . . . . . . . . 5
2.4 Operational safety . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.5 Product safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 Product description . . . . . . . . . . . . . . . 6
3.1 Signal transmission . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 Signal analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3 Product structure . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.4 System components . . . . . . . . . . . . . . . . . . . . . . . . 8
4 Incoming acceptance and product
identification. . . . . . . . . . . . . . . . . . . . . 8
4.1 Incoming acceptance . . . . . . . . . . . . . . . . . . . . . . . 8
4.2 Product configuration: www.endress.com . . . . . . . . 9
4.3 Product identification . . . . . . . . . . . . . . . . . . . . . . . 9
5 Storage and transport . . . . . . . . . . . . . 10
5.1 Storage conditions . . . . . . . . . . . . . . . . . . . . . . . . 10
5.2 Transporting the product . . . . . . . . . . . . . . . . . . . 10
6 Installation . . . . . . . . . . . . . . . . . . . . . 11
6.1 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.2 Installation instructions . . . . . . . . . . . . . . . . . . . . . 11
6.3 Mounting the device . . . . . . . . . . . . . . . . . . . . . . 14
6.4 Post-installation check . . . . . . . . . . . . . . . . . . . . . 15
7 Electrical connection . . . . . . . . . . . . . 15
7.1 Cable diameter and wire cross-section . . . . . . . . . 15
7.2 Connection data . . . . . . . . . . . . . . . . . . . . . . . . . . 15
7.3 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.4 Connecting the device . . . . . . . . . . . . . . . . . . . . . 17
7.5 Function monitoring . . . . . . . . . . . . . . . . . . . . . . . 18
7.6 Post-connection check . . . . . . . . . . . . . . . . . . . . . 18
8 Operation . . . . . . . . . . . . . . . . . . . . . 19
8.1 Operating and display elements . . . . . . . . . . . . . . 19
9 Commissioning. . . . . . . . . . . . . . . . . . 20
9.1 Function check . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
9.2 Interlocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
9.3 Performing a proof test . . . . . . . . . . . . . . . . . . . . . 21
9.4 Device behavior during operation . . . . . . . . . . . . . 22
10 Troubleshooting. . . . . . . . . . . . . . . . . . 24
10.1 Response of outputs to alarms . . . . . . . . . . . . . . . . 24
10.2 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10.3 Replacing the fuses . . . . . . . . . . . . . . . . . . . . . . . . 28
10.4 Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
11 Technical data . . . . . . . . . . . . . . . . . . . 30
12 Repair . . . . . . . . . . . . . . . . . . . . . . . . . 30
12.1 Repairing Ex-certified devices . . . . . . . . . . . . . . . . 30
12.2 Replacing a device . . . . . . . . . . . . . . . . . . . . . . . . 30
13 Maintenance . . . . . . . . . . . . . . . . . . . . 30
14 Return . . . . . . . . . . . . . . . . . . . . . . . . . 31
15 Disposal . . . . . . . . . . . . . . . . . . . . . . . . 31

Nivotester FailSafe FTL825 Important document information
Endress+Hauser 3
1 Important document information
1.1 About this document
1.1.1 Document function
These Operating Instructions contain all the information that is required in the various phases of the
life cycle of the device: from product identification, incoming acceptance and storage, to mounting,
connection, operation and commissioning through to troubleshooting, maintenance and disposal.
1.1.2 Additional standard device documentation
1.1.3 Safety Instructions (XA) for the device
Depending on the device approval Safety Instructions (XA) are supplied with the device. These are
considered an integral part of the Operating Instructions.
!Note!
The document types listed are available at: www.endress.com Download
Document Purpose and content of the document
TI01027F Planning aid for your device (Technical Information)
The document contains all the technical data on the device and provides an overview
of the accessories and other products that can be ordered for the device.
TI00367F Protective housing IP 66 for field mounting of top-hat rail devices
SD00350F Functional Safety Manual
Document Type of protection
XA00603F ATEX Ex ia G/D
ATEX II (1)G [Ex ia Ga] IIC
ATEX II (1)D [Ex ia Da] IIIC,
IECEx Ex ia G/D
IECEx [Ex ia Ga] IIC
IECEx [Ex ia Da] IIIC,
ATEX/IECEx Ex ia G/D
ATEX II (1)G [Ex ia Ga] IIC
ATEX II (1)D [Ex ia Da] IIIC
IECEx [Ex ia Ga] IIC
IECEx [Ex ia Da] IIIC
XA00647F CSA C/US AIS/ANI
AIS Cl. I, II, III, Div 1, Gr. A-G, [AEx/Ex ia] IIC
ANI Cl. I, Div 2 Gr. A-D [AEx/Ex ic/nL] IIC
XA00646F FM C/US AIS/ANI
AIS Cl. I, II, III, Div 1, Gr. A-G, [AEx/Ex ia] IIC
ANI Cl. I, Div 2 Gr. A-D [AEx/Ex ic/nL] IIC
XA00663F NEPSI Ex ia G/D
NEPSI [Ex ia Ga] IIC
NEPSI [Ex ia Da] IIIC

Important document information Nivotester FailSafe FTL825
4Endress+Hauser
1.2 Notes on safety conventions and icons
In order to highlight safety-related or alternative operating procedures in the manual, the following
conventions have been used, each indicated by a corresponding icon in the margin.
Safety instructions
#Warning!
Indicates an action or procedure which, if not performed correctly, can result in serious personal
injury, a safety hazard or the destruction of the device.
"Caution!
Indicates an action or procedure which, if not performed correctly, can result in personal injury or
the incorrect operation of the device.
!Note!
Indicates an action or procedure which, if not performed correctly, can have an indirect effect on
operation or trigger an unexpected response on the part of the device.
Type of protection
0Explosion-protected, type-examined equipment
If this symbol appears on the nameplate of the device, the device can be used in hazardous or non-
hazardous areas according to its approval.
-Hazardous area
This symbol is used in the drawings of these Operating Instructions to indicate hazardous areas.
Devices in hazardous areas, or cables for such devices, must have an appropriate type of protection.
.Safe area (non-hazardous area)
This symbol is used in the drawings of these Operating Instructions to indicate non-hazardous areas.
Devices in the non-hazardous area also have to be certified if connecting cables lead into the
hazardous area.
Electrical symbols
%Direct current
A terminal at which DC voltage is present or through which direct current flows.
&Alternating current
A terminal at which alternating voltage (sinusoidal) is present or through which alternating current
flows.
Connecting cable immunity to temperature change
Indicates that the connecting cables must be able to withstand temperatures of at least 85 °C.
LED symbols
Not relevant
Off
Flashing
Lit
t >85°C

Nivotester FailSafe FTL825 Basic safety instructions
Endress+Hauser 5
2 Basic safety instructions
2.1 Personnel requirements
The personnel for installation, commissioning, diagnostics and maintenance must fulfill the
following requirements:
• Trained, qualified specialists must have a relevant qualification for this specific task
• Are authorized by the plant owner/operator
• Are familiar with federal/national regulations
• Before beginning work, the specialist staff must have read and understood the instructions in the
Operating Instructions and supplementary documentation as well as in the certificates (depending
on the application)
• Follow instructions and comply with conditions
• Be instructed and authorized according to the requirements of the task by the facility's owner-
operator
• Follow the instructions in these Operating Instructions
2.2 Designated use
Functional Safety Manual
"Caution!
Pay close attention to the information in the separate SIL documentation SD00350F for functional
safety requirements in accordance with IEC 61508.
Application and media
The measuring device described in this manual may only be used in conjunction with Liquiphant
FailSafe FTL8x from Endress+Hauser. In compliance with the limit values specified in the
"Technical data" section and the general conditions indicated in the manual and supplementary
documentation, the measuring system may only be used for the following measurements:
• Measured variables: point level
To ensure that the measuring device remains in proper operating condition for its service life, all the
limit values must be observed.
• Technical data in the related documentation ä3.
Incorrect use
The manufacturer is not liable for damage resulting from improper or non-designated use.
2.3 Occupational safety
When working on or with the device, always wear the necessary personal protective equipment as
defined in national regulations.
2.4 Operational safety
"Caution! Risk of injury.
• Only operate the device if it is in a perfect technical condition free from errors and faults.
• The operator is responsible for the trouble-free operation of the device.
Conversions to the device
Unauthorized modifications to the device are not permitted.

Product description Nivotester FailSafe FTL825
6Endress+Hauser
Repair
To ensure operational safety:
• Only perform repair work on the device if this is expressly permitted.
• Comply strictly with national regulations concerning the repair of electrical equipment.
• Only use genuine Endress+Hauser spare parts and accessories.
Hazardous area
To exclude any risks to individuals or the facility when operating the device in the hazardous areas
(e.g. explosion protection, pressure equipment safety):
• Based on the nameplate, check whether the ordered device is permitted for the intended use in
the hazardous area.
• Comply with the instructions in the separate supplementary documentation, which is an integral
part of this manual.
2.5 Product safety
This measuring device is designed to meet state-of-the-art safety requirements in accordance with
sound engineering practice, has been tested and left the factory in a condition in which it is safe to
operate.
It meets general safety standards and legal requirements. Furthermore, it complies with the EC
directives which are listed in the device-specific EC Declaration of Conformity. Endress+Hauser
confirms this by affixing the CE mark to the device.
3 Product description
The Nivotester FailSafe FTL825 is a transmitter power supply unit for the Liquiphant FailSafe
FTL8x. Outstanding features of the Nivotester FailSafe FTL825 include:
• Fail-safe point level detection in liquids
• For point level switches up to Zone 0
• Pump dry running protection and overfill protection for tanks with flammable, explosive, toxic
(water-polluting) liquids
• Use in safety systems requiring functional safety to SIL3 in accordance with IEC 61508 Ed.2.0 /
IEC 61511-1 / ISA 84-1
3.1 Signal transmission
The Nivotester supplies direct current to the Liquiphant FailSafe FTL8x point level switch via a two-
wire cable. At the same time, it analyzes the current values (4 to 20 mA discrete) of the Liquiphant
and returns a switching signal. The signal inputs of the Nivotester FTL825 are galvanically isolated
from the mains and the output and can be ordered as intrinsically safe inputs.
LIVE signal
It is possible to automatically check whether a Liquiphant FailSafe FTL8x is connected. For this
purpose a LIVE signal is modulated within the range limits.
The LIVE signal is a square-wave signal of 0.25 Hz and ±0.5 mA amplitude (the signal changes by
1 mA every 2000 ms ±50 ms).

Nivotester FailSafe FTL825 Product description
Endress+Hauser 7
3.2 Signal analysis
The Nivotester FailSafe FTL825:
• Evaluates the current and switches the safety contacts for the level alarm accordingly
• Switches a signaling contact in addition to the safety contacts
• Switches a separate fault-signaling contact in the event of a device malfunction
• Evaluates a dynamic signal (LIVE signal) and indicates the status of this signal using an LED
• Signals the switching state on the front panel by means of a yellow LED
3.3 Product structure
3.3.1 Top terminal blocks
• 2 screw terminals: sensor connection MAX detection (91, 92)
• 2 screw terminals: sensor connection MIN detection (83, 82)
3.3.2 Bottom terminal blocks
• 4 screw terminals: fault-signaling contact (4, 5, 6) and remote control (52)
• 4 screw terminals: supply voltage (1, 2) and unlocking (50, 51)
• 3 screw terminals: safety contacts (13, 23) and signaling contact (31)
• 3 screw terminals: safety contacts (14, 24) and signaling contact (32)
3.3.3 Proof test button
The proof test button is used to confirm configuration changes and enable the proof test.
3.3.4 Interlock switch
The interlock switch is used to secure a certain operating mode.
3.3.5 Light emitting diodes (LEDs)
The light emitting diodes are used to indicate different operating states.
3.3.6 Fuses
The two output channels are protected against damage by two fuses.

Incoming acceptance and product identification Nivotester FailSafe FTL825
8Endress+Hauser
3.4 System components
The measuring system consists of the following components:
• Nivotester FailSafe FTL825 (transmitter supply unit)
• Liquiphant FailSafe FTL8x with FEL85 electronic insert (point level switch)
TI01005F_xx_000
1 Liquiphant FailSafe FTL8x with FEL85 electronic insert (4-20 mA)
2 Separate switching unit: Nivotester FailSafe FTL825
3Actuator
4 Incoming acceptance and product identification
4.1 Incoming acceptance
Is the order code on the delivery note (1) identical to the order code on the product sticker (2)?
Do the data on the nameplate match the order data and the delivery note?
.
1
2
3
-
13 23 31
91 92
45652
A0013696
TI01005F_xx_015
TI01005F_xx_016
DELIVERY NOTE
1= 2

Nivotester FailSafe FTL825 Incoming acceptance and product identification
Endress+Hauser 9
4.2 Product configuration: www.endress.com
Detailed ordering information is available:
• In the Product configurator on the Endress+Hauser website: www.endress.com Select
countryInstrumentsSelect deviceProduct page function: Configure this product
• From your Endress+Hauser sales center: www.endress.com/worldwide
!Note! Product configurator - the tool for individual product configuration
• Up-to-date configuration data
• Direct entry of data specific to the measuring point, such as the measuring range or operating
language, depending on the device
• Exclusion criteria automatically checked
• Automatic order code generation with code breakdown output in PDF or Excel format
• Possible to order directly in the Endress+Hauser online shop
4.3 Product identification
It is possible to identify the measuring device in the following ways:
• Using the nameplate specifications
• Using the order code with a breakdown of the device features on the delivery note
• By entering the serial number on the nameplates into the W@M Device Viewer
(www.endress.com/deviceviewer): All the information pertaining to the measuring device is
displayed.
For an overview of the scope of the technical documentation supplied with the device, enter the
serial number on the nameplates into the W@M Device Viewer (www.endress.com/deviceviewer)
A0013696
TI01005F_xx_018
DELIVERY NOTE
Made in Germany, 79689 Maulburg
FTL825
MIN
MAX

Storage and transport Nivotester FailSafe FTL825
10 Endress+Hauser
4.3.1 Nameplate
BA01038F_04
1 Order code
2 Certificate symbols
3 Document numbers of Safety Instructions: e.g. XA, ZD, ZE
4 Certificate- and approval-specific data
5CEmark
6Layoutnumber
7 Power supply data
8 Barcode (serial number)
9 Information on certificates and approvals
10 Serial number
11 Order number
12 TAG number
13 Manufacturer's address
14 Barcode (order number)
15 Connection data
5 Storage and transport
5.1 Storage conditions
–20 to +85 °C preferably at +20 °C (–4 to +185 °F preferably +68 °F)
5.2 Transporting the product
Transport the measuring device to the measuring point in its original packaging.
Nivotester
-20 °C Tamb +60 °C
-20 °C Tamb +50 °C (Anreihmontage/
row mounting)
50 51
L-
12
L+
652
45
32
14
24
13 23 31
250 V AC, 2 A, 500 VA
40 V DC, 2 A, 80 W (cos 0,7)
Contact rating
Ser. no.:
Kom. no.:
FTL825-
U:
I:
U:
I:
TAG no.:
3
8
7
6
1
15
10
245
9
11121314

Nivotester FailSafe FTL825 Installation
Endress+Hauser 11
6 Installation
6.1 Dimensions
L00-FTC625xx-06-06-xx-xx-002
6.2 Installation instructions
6.2.1 Orientation
• Housing: plastic row housing
• Mounting: vertically, on DIN rail to EN 60715 TH 35-7.5 or EN 60715 TH 35-15
L00-FTL825xx-11-06-xx-xx-004
1 EN 60715 TH 35-7.5 mm (1.38-0.3 in) or EN 60715 TH 35-15 mm (1.38-0.6 in)
6.2.2 Installation location
The Nivotester must be installed outside the hazardous area. It has been designed for installation in
a cabinet. A protective housing (IP66) for up to two Nivotester FailSafe FTL825 devices is also
available for mounting in the open air. For additional information on the protective housing: ä3
"Additional standard device documentation"
112 (4.41)
95 (3.74)
108 (4.25)
45(1.77)
mm (in)
1

Installation Nivotester FailSafe FTL825
12 Endress+Hauser
L00-FTL825xx-11-06-xx-xx-001
1 Liquiphant FTL
2NivotesterFTL
3IP65
L00-FTC625xx-06-06-xx-xx-001
6.2.3 Environment
For individual mounting
• –20 to +60 °C (–4 to +140 °F)
For series mounting without lateral spacing
• –20 to +50 °C (–4 to +122 °F)
-
.
1
3
2
mm (in)
-
.
≥50 (2)≥50 (2)
≥50 (2)
-

Nivotester FailSafe FTL825 Installation
Endress+Hauser 13
When installing in protective housing
• –20 to +50 °C (–4 to +122 °F)
• A maximum of three Nivotesters may be installed in the protective housing in order to ensure
adequate ventilation. For further information on the protective housing: ä3 "Additional
standard device documentation"
"Caution!
The devices should be mounted in areas which are protected from weather conditions and impact
and, if possible, which are not exposed to direct sunlight. This factor should be observed particularly
in warm climates.
6.2.4 Climatic and mechanical application class
3K3
In accordance with DIN EN 60721-3-3
3M2
In accordance with DIN EN 60721-3-3
Humidity
• 5-95% (non-condensating)
6.2.5 Vibration resistance
As per IEC 60068-2-64, load class 0.5 (m/s²)²/Hz, 3 x 100 minutes
6.2.6 Degree of protection
IP20
6.2.7 Electromagnetic compatibility (EMC)
Interference emission to EN 61326, Electrical Equipment Class B
Interference immunity to EN 61326-3-2; Appendix A (industrial) and NAMUR Recommendation
NE 21
6.2.8 Material
Housing
• Polycarbonate
Color: light-gray
Front cover
• Polypropylene PPN
Color: charcoal-gray
Fixing slide (for securing on DIN rail)
• Polycarbonate
Color: light-gray
6.2.9 Weight
Approx. 270 g (9.52 oz)

Installation Nivotester FailSafe FTL825
14 Endress+Hauser
6.3 Mounting the device
6.3.1 Tools
Screwdriver
6.3.2 Installation in a cabinet
"Caution!
Comply with instructions concerning the installation location and spacing! ä11 "Installation
location"
BA01038F_01
A EN 500222 TH 35-7.5 mm (1.38-0.3 in) or EN 60715 TH 35-15 mm (1.38-0.6 in)
Locking the device into place on the top-hat rail:
Fit the device on the top-hat rail.
Press the device onto the top-hat rail until it snaps into place.
6.3.3 Removing the device from the top-hat rail
BA01038F_03
Example
Push down the catch.
Lift the device slightly.
A
1.
2.
1.
2.

Nivotester FailSafe FTL825 Electrical connection
Endress+Hauser 15
6.3.4 Removing the terminal blocks
BA01038F_02
Example
Use the screwdriver as a lever.
Lift up the terminal block.
6.4 Post-installation check
7 Electrical connection
"Caution!
Comply with national standards and regulations!
7.1 Cable diameter and wire cross-section
Maximum permitted wire cross-section 1 x 2.5 mm2 (1 x 14 AWG) or 2 x 1.5 mm2(2 x 16 AWG).
For additional information, see Operating Instructions BA01037F for Liquiphant FailSafe FTL8x.
7.2 Connection data
7.2.1 Terminal blocks
The removable terminal blocks (intrinsically safe version) are divided into intrinsically safe circuits
(at the top of the device) and non-intrinsically safe circuits (at the bottom of the device). This
distinction enables the safe routing of the connecting cable.
7.2.2 Connecting the point level switch (top terminal blocks)
Only one single Liquiphant FailSafe FTL8x point level switch may be connected to the Nivotester
FailSafe FTL825. A commercially available instrument cable can be used for the twin-core
1.
Is the device undamaged (visual inspection)?
Does the device meet the specifications of the measuring point, e.g. ambient temperature?
Are the measuring point identification and labeling correct (visual inspection)?
Is the device adequately protected from precipitation and direct sunlight?
Are the securing screw and securing clamp securely tightened?
Have functional safety requirements been considered (optional)?
2.

Electrical connection Nivotester FailSafe FTL825
16 Endress+Hauser
connecting cable between the two devices. Maximum 25 cable resistance per core. Maximum
cable capacitance 100 nF (typically 1000 m (3281 ft)).
A shielded cable should be used if strong electromagnetic interference is expected (from machines
or radio equipment). The shield is connected to the ground connection in the point level switch.
The use of shielded cables can improve EMC interference immunity.
7.2.3 Using the point level switch in hazardous areas
Observe national explosion protection regulations surrounding the design and routing of
intrinsically safe signal cables.
Please refer to the associated safety instructions for information on the capacitance and inductance
limit values. For more information on the documents, ä3.
7.2.4 Connecting the signal and control units (bottom terminal blocks)
Pay attention to the function of the output contacts depending on the level and operating mode. If
a high-inductance device is connected (e.g. contactor, solenoid valve etc.), a spark arrester must be
provided to protect the contacts.
•Relayoutputs:
– Two floating NO contacts (supervised safety contacts based on the quiescent current principle)
with integrated 3.15 A fuse (exchangeable)
Quiescent current operating mode: MIN/MAX (operating mode can be selected with
connection wiring)
– One floating NC contact (signaling contact)
– Fault-signaling relay: floating changeover contact for fault signaling
• Switching capacity per relay contact:
U ~ maximum 253 V
I ~ maximum 2 A
P ~ maximum 500 VA at cos 0.7
U = maximum 40 V
I = maximum 2 A
P = maximum 80 W
• Operating life: at least 105switching operations with maximum contact load
• Recommended minimum current: 1 mA
• Function indicators: light emitting diodes for operation, point level and fault
• Sum of voltages of relay output and power supply max. 300 V
7.2.5 Connecting the supply voltage (bottom terminal blocks)
As a non-replaceable fuse is incorporated in the power supply circuit it is not necessary to connect
an upstream fine-wire fuse. The Nivotester has reverse polarity protection.
7.3 Power supply
7.3.1 Mains voltage version
• Nominal supply voltage: AC/DC 230/115 V
• Supply voltage range:
AC 85 to 253 V, 50/60 Hz
DC 85 to 253 V
• Power consumption: 3.8 VA, 2.0 W

Nivotester FailSafe FTL825 Electrical connection
Endress+Hauser 17
7.3.2 Extra-low voltage version
• Nominal supply voltage: AC/DC 24 V
• Supply voltage range:
AC 20 to 30 V, 50/60 Hz
DC 20 to 60 V
• D/C power supply: maximum 95 mA
• Permitted residual ripple inside the tolerance: Uss = maximum 2 V
Power consumption: 3.6 VA, 2.5 W
Reverse polarity protection: yes
Overvoltage protection FTL825: category II (2000 m (6562 ft) above MSL)
7.3.3 Galvanic isolation
All the input and output channels and the relay contacts are galvanically isolated safely from one
another. Safe galvanic isolation is guaranteed up to a voltage of 150 V AC if the supply circuit or the
contacts of the fault-signaling relay are connected simultaneously to the functional extra-low
voltage.
7.4 Connecting the device
7.4.1 Connection depending on the operating mode
Minimum/maximum detection (MIN/MAX) is selected by connection coding on the electronic
insert.
A: MIN = minimum detection:
The output switches in a safety-oriented manner when the probe is uncovered (demand mode).
Used for dry running protection, pump protection for example.
B: MAX = maximum detection:
The output switches in a safety-oriented manner when the probe is covered (demand mode).
Used for overfill protection for example.
SD00350Fxx11
A Minimum detection (dry running protection)
B Maximum detection (overfill protection)
8
9
8
9
2
2
3
1
12 3 12 3
FEL85 FEL85
MAX MINMAX MIN
–+– – +–
(–)(–)(+)(+)
83 82 91 92
AB

Electrical connection Nivotester FailSafe FTL825
18 Endress+Hauser
7.4.2 All the connections on the Nivotester FailSafe FTL8x
BA01038F_05
AFrontcover(open)
Terminal blocks:
X1, gray (top): 2 screw terminals, sensor connection MAX detection (91, 92)
X2, gray (top): 2 screw terminals, sensor connection MIN detection (83, 82)
X1, gray (bottom): 4 screw terminals, fault-signaling contact (4, 5, 6) and remote control (52)
X2, green (bottom): 4 screw terminals, supply voltage (1, 2) and unlocking (50, 51)
X1, gray (bottom): 3 screw terminals, safety contacts (13, 23) and signaling contact (31)
X2, gray (bottom): 3 screw terminals, safety contacts (14, 24) and signaling contact (32)
7.5 Function monitoring
To increase operational safety, the Nivotester is equipped with permanent function monitoring. A
fault is indicated by a red light emitting diode, the safety contacts open and the fault-signaling
contact is de-energized (without power) in the event of errors caused by:
• Point level switch (3.6 mA)
•Faultywiring
•Nivotester
•NoLIVEsignal
Additional information ä24 "Troubleshooting".
7.6 Post-connection check
12
50 51
52
456 13 31
14 3224 X2
X1
9291
8283
23
X1
X2
32
14
24
X2X2
50 51
MIN
MAX
N
12
L1
L+ L-
83 82
91 92
X2X2
X1X1
- +
13 23 31
X1X1
652
45
ON
OFF
FTL825
MIN
MAX
A
Are cables or the device undamaged (visual inspection)?
Do the cables used comply with the requirements?
Does the supply voltage match the specifications on the nameplate?
Is the terminal assignment correct?
If power is supplied, is the device ready for operation?

Nivotester FailSafe FTL825 Operation
Endress+Hauser 19
8Operation
8.1 Operating and display elements
Carefully open the front cover with a screwdriver.
FTL825_1
Operating elements
• 1: proof test button (T)
• 2: interlock switch
Display elements: light emitting diodes (LEDs)
3: LEDs (from left)
• LIVE signal (flashes yellow) and interlocking (lit yellow)
• Sensor covered (yellow)
• Faulty wiring (red)
• Liquiphant fault (red)
4: LEDs (from left)
• MIN detection mode (green)
• MAX detection mode (green)
• Nivotester fault (red)
• Safety contacts closed (yellow)
Fuses
5: Two replaceable fuses for the two safety contacts (ä29 "Spare parts")
(3.15 A; T; 250 V; design 5x20)
FTL825
MIN
MAX
x2
5
MIN
MAX
-+
x2
x2
x1
x1
x2
x1
x1
x2
52
51
31
32
23
24
ON
OFF !i
13
14
T
6
50
5
2
4
1
L+L-
L1N
91 92
82
83
4
1
3
2

Commissioning Nivotester FailSafe FTL825
20 Endress+Hauser
9 Commissioning
9.1 Function check
Make sure that the post-installation and post-connection checks have been completed before you
commission the measuring point:
• Checklist for "Post-installation check" ä15
• Checklist for "Post-connection check" ä18
9.2 Interlocking
Interlocking prevents the device from restarting automatically (safety contacts enabled) when the
demand mode or a malfunction is over. This state is maintained until the system is unlocked again.
!Note!
To use the interlock, a key must be wired between terminals 50/51. To unlock the system, these
two terminals must be short-circuited for at least 1 second.
BA01038F_07
A Key to acknowledge demand mode in the interlocked state
B Configuration via the interlock switch (ON/OFF)
!Note!
Each change to the configuration generates an alarm:
• LED "Nivotester fault (red)" flashes
• All outputs assume the safety-oriented state ä24 "Response of outputs to alarms"
• The change is only enabled when the proof test button is pressed by way of confirmation
If a proof test is performed in the interlocked state, the system must be unlocked afterwards before
regular operation can resume.
X2
50 51
N
12
L1
L+ L-
ON
OFF
AB
Configuration via the interlock switch "B" Switch position
Interlocked (demand mode or malfunction (latching)) Open (ON)
Automatic restart (in the "Good" state) Closed (OFF)