Testo 6651, 6681 Operating Manual

testo 6681 · Humidity transmitters

testo 6610 · Probes

P2A software · Parameterizing, adjusting and analyzing

software

Instruction manual en

Safety and the environment

Avoiding electrical hazards

► Never use the instrument and connected probes to measure on or near

live parts!

► Damaged mains cables must only be replaced by authorized personnel. ► Only have the transmitter wired and connected by authorized personnel

with the voltage disconnected.

► You must always comply with the regulations applicable in your country

to the opening and repair of electrical equipment.

Avoiding personal injury/damage to equipment

► Installation, setting and calibration work must only be carried out by

qualified and authorized personnel!

► Only open the instrument when this is expressly described in the

instruction manual for installation, maintenance or repair purp oses.

► Observe the permissible storage, transport and operating temperatures. ► Never store or operate the product with solvents and do not use any

desiccants.

► Do not use the instrument for control purposes at the same time as

operating or servicing the transmitter.

► Only operate the product properly, for its intended purpose and within the

parameters specified in the technical data. Do not use force.

► Carry out only the maintenance and repair work that is described in the

documentation. Follow the prescribed steps when doing so. Use only OEM spare parts from Testo.

Any additional work must only be carried out by authorized personnel. Otherwise Testo will not accept any responsibility for the proper functioning of the instrument after repair and for the validity of certifications.

Protecting the environment

► Send the product back to Testo at the end of its useful life. We will

ensure that it is disposed of in an environmentally friendly manner.

About this document

► Please read this documentation through carefully and familiarize yourself

with the product before putting it to use. Keep this document to hand so that you can refer to it when necessary. Hand this documentation on to any subsequent users of the product.

► The following conventions are followed in this document:

Character/ display:

Explanation/example

With the signal word Warning!: Warns against hazards which could result in serious physical

injury if the precautionary measures indicated are not taken, e.g.:

De-energize the mains connection before connecting the transmitter!

With the signal word Caution!:





Warns against hazards which could result in minor physical injury or damage to equipment if the precautionary measures indicated are not taken, e.g.:

Observe the permissible operating temperature!

Important information, e.g.: Administrator rights are required to install the program under

Windows

2000, XP and Vista.

Aim of action, e.g.:

 Assembling the instrument at the process

connection:

Requirement that must be met, e.g.:

 USB drivers are installed.

About this document

Steps are numbered if a certain sequence of actions must be followed, e.g.:

1 Loosen and remove housing screws. 2 Remove the upper part of housing.



" to "

Bold type

…>…

[ ]

CAPITAL LETTERS

A step is not numbered if there are no further steps or if the step is optional, e.g.:

▪ Insert probe connector into socket of testo 6681 until

it engages.

Example entries are in inverted commas, e.g.:

The value "0" results in ....

Elements of the program interface or instrument display, e.g.:

The instrument designation appears in the instrument/parameter file list.

Select Main Menu Channel 1 and confirm with SET.

Functions/paths within a menu, e.g.: Start > All Programmes > Testo > Transmitter Software.

Buttons which start an action, e.g.: Confirm the software key with [OK].

Keys on the instrument or keypad, e.g.: Press ESC.

Contents

1 TRANSMITTER............................................................................................8

1.1 Specifications...........................................................................................8

1.1.1 Functions and use.......................................................................8

1.1.2 Scope of delivery.........................................................................8

1.1.3 Accessories.................................................................................9

1.1.4 Technical Data............................................................................9

1.1.5 Dimensions ...............................................................................10

1.2 Product description................................................................................11

1.2.1 At a glance................................................................................11

1.2.2 Usable probes...........................................................................12

1.2.3 Display and keypad...................................................................12

1.2.4 Service interface .......................................................................12

1.2.5 Relay board (option)..................................................................13

1.2.6 analog outputs...........................................................................13

1.2.7 Parameters................................................................................13

1.2.8 Scaling ......................................................................................14

1.2.9 Alarm handling..........................................................................17

1.3 Commissioning......................................................................................18

1.3.1 Assembling the instrument........................................................18

1.3.2 Connecting the instrument........................................................21

1.3.3 Adjusting the instrument............................................................33

1.4 Operation...............................................................................................42

1.4.1 Relationship between user menu and mini-DIN socket

is active.....................................................................................42

1.4.2 Key cover ..................................................................................42

1.4.3 Password protection..................................................................44

1.4.4 Structure of user menu..............................................................44

1.4.5 Ov e r v i e w o f t h e t e s t o 6 6 8 1 u s e r m e n u............................................46

1.4.6 The individual main menus .......................................................48

1.5 Status, warning and error messages.....................................................60

1.5.1 Status messages.......................................................................60

1.5.2 Warning messages ...................................................................61

1.5.3 Error messages.........................................................................63

1.5.4 Handling alarm messages ........................................................64

1.5.5 Namur fault conditions ..............................................................66

1.6 Maintenance and cleaning.....................................................................67

1.6.1 Maintaining the instrument........................................................67

1.6.2 Cleaning the instrument............................................................67

Contents

2 TESTO 6610 PROBES...............................................................................68

2.1 Specifications.........................................................................................68

2.1.1 Functions and use.....................................................................68

2.1.2 Design of the probe...................................................................70

2.1.3 Accessories...............................................................................71

2.2 Product description................................................................................71

2.2.1 Overview of probe and filter types ............................................71

2.2.2 testo 6611 wall probe................................................................76

2.2.3 testo 6612 duct probe...............................................................79

2.2.4 testo 6613 cable probe .............................................................83

2.2.5 testo 6615 trace humidity cable probe (self-adjustment)..........90

testo 6617 cable probe (self-monitoring)...............................................94

2.2.6 testo 6622 duct probe...............................................................98

2.2.7 testo 6623 cable probe ...........................................................101

2.3 Commissioning....................................................................................104

2.3.1 Installing the probe..................................................................104

2.3.2 Connecting/removingthe probe to/from the transmitter ..........108

2.4 Maintenance and cleaning...................................................................109

2.4.1 Replacing filters/protection caps.............................................109

2.4.2 Cleaning the instrument and filter/protection cap ...................112

2.4.3 Replacing the sensor ..............................................................112

3 PARAMETERIZING, AD JUSTING AND ANALYZI NG SOFT WARE

SOFTWARE)..................................................................................113

(P2A

3.1 Specifications.......................................................................................113

3.1.1 Functions and use...................................................................113

3.1.2 System requirements..............................................................114

3.1.3 Scope of delivery ....................................................................114

3.2 First steps............................................................................................115

3.2.1 Installing the software/driver...................................................115

3.2.2 Starting the software...............................................................116

3.3 Using the software...............................................................................117

3.3.1 User interface..........................................................................117

3.3.2 Editing instrument/parameter file............................................119

3.3.3 Analyzing/testing the transmitter.............................................128

3.3.4 Adjusting the transmitter.........................................................134

3.3.5 Transmitter history ..................................................................139

Contents

4 TIPS AND ASSISTANCE............................................................................145

4.1 Questions and answers.......................................................................145

4.2 Accessories and spare parts...............................................................146

4.2.1 Ordering options for testo 6681 transmitter (0555 6681)..................148

4.2.2 Ordering options for testo 6610 probes (0555 6610)......................152

testo 6681 - 1.1 Specifications

1 Transmitter

1.1 Specifications

1.1.1 Functions and use

The testo 6681 humidity transmitter is used in conjunction with plug-in, adjusted probes from the testo 6610 range.

Please refer to Chapter 2 testo 6610 probes for information about commissioning, operating and maintaining the

The testo 6681 humidity transmitter is suitable for the following applications, for example:

• Process instrumentation

• Clean rooms

• Test benches

• Drying processes

• Production and storage air quality

• Complex room climate applications.

testo 6610 probe.

1.1.2 Scope of delivery

The scope of delivery of the testo 6681 humidity transmitter includes the following:

• Key cover

• Rear panel bracket

• CD-ROM with catalogue files (PDF) and P2A update (this can onl y be

used in conjunction with the P2A software, which has to be ordered separately).

testo 6681 - 1.1 Specifications

1.1.3 Accessories

The following accessories are available for the testo 6681 humidity transmitter:

• Protection caps for probes

• Mains unit

• P2A software (parameterizing, adjusting and analyzing software)

• Assembly accessories.

Information about accessories and their order numbers can be found in Chapter 4.2 Accessories and spare parts or on the website at www.testo.com.

1.1.4 Technical Data

Parameters

- Humidity (various variables and

units)

- Temperature (°C/°F)

Measuring range

- Depends on probe

Accuracy

- Depends on probe

Resolution

- 0.1 % RH or 0.1 °C/0.1 °F

Meas. cycle

- 1/s

Interface

- Mini-DIN for P2A software

(parameterizing and adjusting software) and handheld testo 400/650

- optional: Profibus-DP module

Voltage supply

- 2-wire: 12 to 30 V DC

- 4-wire (separate signal and supply

lines): 20 - 30 V AC/DC, 300 mA power consumption

Maximum load

- 2-wire: 100 to 750 Ω

- 4-wire: 500 Ω (power output)

testo 6681 - 1.1 Specifications

Analog output

- 4 to 20 mA ± 0.03 mA (2-wire) or

- 0 to 1 V ± 1.5 mV (4-wire) or

- 0 to 5 V ± 7.5 mV (4-wire) or

- 0 to 10 V ± 15 mV (4-wire) or

- 0 to 20 mA ± 0.03 mA (4-wire) or

- 4 to 20 mA ± 0.03 mA (4-wire)

Resolution of analog output

- 12 bit

Relay

- 4 relays, 250 V AC/DC, 3 A

(optional)

Display

- 2-line LCD with plain text line

(optional)

Housing operating temperature

1.1.5 Dimensions

- -40 to 70 °C/-40 to +158 °F, with

display from 0 - 50 °C/+32 to +122 °F

- With integrated relay: -40 to +60°C

Storage temperature

- - 40 to 80 °C/-40 to +176 °F

Housing, weight

- Metal, 1.960 kg/432 lb

Protection class

- IP 65 only if the transmitter is wired

and/or seal plugs are inserted

Directives, standards and tests

- EC Directive: 2004/108/EC

- EN 61326

Warranty

- Duration: 2 years

- Warranty conditions: See

guarantee card

Dimensions in mm a b

With M 20 cable couplings 144 147 With NPT cable couplings 144 144 With plug-in connections 143

testo 6681 - 1.2 Product description

1.2 Product description

1.2.1 At a glance

1 Keys (only with optional display) 2 Service flap screw connection

(self-locking, 2x) 3 Display (optional) 4 Service flap 5 M 16 x 1.5 screw connection*,

e.g. analog outputs 6 M 16 x 1.5 screw connection*,

e.g. voltage supply 7 Earthing/PE connection 8 M 20 x 1.5 screw connection*,

e.g. relay R 3 and R 4 9 Eyelet for measuring point panel 10 M 20 x 1.5 screw connection*,

e.g. relay R 1 and R 2 11 Probe connector (testo 6610) 12 Upper part of housing * Alternatively, NPT cable

couplings or M plug-in

connections are available

13 Housing screws 14 Socket for probe connector

15 Hole for fastening to rear panel

bracket (M3 x 6 screw) 16 Plastic bracket for assembly on

rear panel

testo 6681 - 1.2 Product description

1.2.2 Usable probes

The testo 6681 humidity transmitter can be used with the following probes:

probe Article no. Characteristic

testo 6611 0555 6610-L11 Wall probe version; accuracy to ± 1 % RH;

testo 6612 0555 6610-L12 Duct probe version; accuracy to ± 1 % RH;

testo 6613 0555 6610-L13 Cable probe version; accuracy to ± 1 % RH;

testo 6614 0555 6610-L14 Heated cable probe version; accuracy to

testo 6615 0555 6610-L15 Trace humidity cable probe version;

testo 6617 0555 6610-L17 Cable with cover electrode monitoring probe

testo 6622 0555 6610-L22 Duct probe version; accuracy to ± 1 % RH;

testo 6623 0555 6610-L23 Cable probe version; accuracy to ± 1 % RH;

temperature range -20 °C to +70 °C/-4 to +158 °F

temperature range -30 °C to +150 °C/-22 to +302 °F

temperature range -40 °C to +180 °C/-40 to +356 °F

± 1.0 % RH; temperature range -40 °C to +180 °C/

-40 to +356 °F

accuracy ± 6 K at -60 °Ctd; temperature range -40 °C to +120 °C/-40 to +248 °F

version; temperature range -40 °C to +180 °C/-40 to +356 °F

temperature range -30 °C to 120 °C/-22 to +248 °F

temperature range -30 °C to +120 °C/-22 to +248 °F

1.2.3 Display and keypad

The display option allows the testo 6681 humidity transmitter to be operated via the display and four keys.

The LCD display consists of two 7-segment lines for displaying readings and units and of an information line (for status messages, for example).

The brightness and contrast of the display and the background lighting (permanent or off) can be changed via the user menu or the P2A software.

1.2.4 Service interface

Behind the service flap is the parameterizing socket (mini-DIN) as an interface to the P2A software or Testo handheld instrument (testo 400/testo 650).

testo 6681 - 1.2 Product description

1.2.5 Relay board (option)

This has a floating switch capacity of 250 V AC/3 A. The switching limits and hysteresis as well as the function as relay for the collective alarm can be set via the display or the P2A software. Further features include:

• Function of changeover contacts (NC/NO contacts) freely selectable

• 12 terminals for a total of 4 relays.

If no relays are available, settings for monitoring limit values or alarms can still be controlled via the display. The alarm status will be shown on the display

Only have the transmitter wired and connected by authorized personnel with the voltage disconnected.

1.2.6 Analog outputs

For analog outputs, the testo 6681 has either

• 2 or optionally 3 current outputs of 4 to 20 mA (2-wire)/0 to 20 mA (4-

wire)/4 to 20 mA (4-wire) or

• 2 or optionally 3 voltage outputs of 0 to 1 V/0 to 5 V/0 to 10 V (4-wire).

The transmitter can be ordered with a third analog output as an option. In 2-wire operation, channel 1 is used for the supply. The two or optionally

three channels are galvanically isolated in both 2- and 4-wire operation.

Operation with the testo 6614 heated probe, the testo 6615 trace humidity probe, the relay and profibus options or with the background lighting of the optional display are only possible in 4-wire operation.

1.2.7 Parameters

The following parameters are displayed:

• Relative humidity in %RH (technical)

• Relative humidity in % WMO* (calculation according to the WMO

standard)

testo 6681 - 1.2 Product description

• Temperature °C and °F

• Dewpoint or pressure dewpoint in °Ctd and °Ftd

• Absolute humidity in g/m³ and gr/ft³

• Degree of humidity in g/kg and gr/lb

• Enthalpy in kJ/kg and BTU/lb

• Psychrometer temperature in °Ctw and °Ftw

• Water vapour partial pressure in hPa and "H

• Water content in ppm

• Dewpoint of H

2O2

and % vol

vol

mixture in °Ctm and °Ftm.

* It is possible that condensation appears as of a displayed humidity starting from 70 % and is shown on the display.

Calculated humidity variables correspond to the medium of air. With other gases/gas compositions, deviations may occur, e.g. with the enthalpy

1.2.8 Scaling

There are three types of min./max. values:

1 The measuring range

The maximum sensor performance is in this range. Values outside of the measuring range are displayed via messages, for example. Measuring range, see table (below).

2 Standard scaling

The output signals are assigned to this measuring range as standard:

- during delivery if no entries are made in the order code

- after exchanging the unit, the measuring range recorded in the instrument is applied as standard.

The transmitter even retains its scaling with the voltage disconnected.

Measuring range, see table (below).

3 The maximum settings for the manual scaling

- the values are not expressly given in the table. The maximum limits can be calculated as follows:

testo 6681 - 1.2 Product description

X = difference between MIN. and MAX. value of the standard scaling (Max. value of standard) + (50 % of X) (Min. value of standard) - (50 % of X)

- It is thus possible to scale beyond the measuring range, e.g. for the adjustment of the scaling limits to standard values of a PLC.

Standard

Measuring

range

Physical

Parameter Unit probe

Temperature °C 6611 -20 +70 -20 +70 °F 6611 -4 +158 -4 +158 °C 6612 -30 +150 -30 +150 °F 6612 -22 +302 -22 +302 °C 6613, 6614, 6617 -40 +180 -40 +180 °F 6613, 6614, 6617 -40 +356 -40 +390 °C 6615 -40 +120 -40 +120 °F 6615 -40 +248 -40 +248 °C 6622, 6623 -30 +120 -30 +120 °F 6622, 6623 -22 +248 -22 +248 relative humidity % RH 0 +100 0 +100 WMO relative humidity % RH, 0 +100 0 +100 Dewpoint/pressure dewpoint °Ctd 6611 -80 +70 -80 +100 °Ftd 6611 -112 +158 -112 +212

°Ctd 6615 -60 +30 -80 +100 °Ftd 6615 -148 +212 -112 +212 Mixture dewpoint (H2O2) °Ctm -20 +100 -20 +100 °Ftm -4 +212 -4 +212 Absolute humidity g/m3 all probes 0 600 0 2000 gr/ft3 0 250 0 800 Degree of humidity g/kg all probes 0 13300 0 950 0

°Ctd °Ftd

6612, 6613, 6614, 6617, 6622, 6623

at 1013 hPa MIN MAX MIN MAX

-20 +100 -80 +100

-112 +212 -112 +212

scaling

MUF

measuring

range

testo 6681 - 1.2 Product description

Standard

Measuring

range

Physical

Parameter Unit probe

gr/lb 0 93000 0 66500 Enthalpy kJ/kg -40 99999 -40 8000 BTU/lb -18 43000 -18 3500 Psychrometer temperature °Ctw -40 100 -40 180 °Ftw -58 210 -40 356 Water content ppm vol H2O 0 99999 0 99999 % vol 0 100 0 100 Water vapour partial pressure hPa 0 1000 0 7000 inchH2O 0 400 0 2800

at 1013 hPa MIN MAX MIN MAX

scaling

MUF

measuring

range

testo 6681 - 1.2 Product description

1.2.9 Alarm handling

For upper and lower alarm limits, individual alarms as well as collective alarms can be specified. If the collective alarm function is activated, an alarm is triggered as soon as the alarm limit of an alarm is exceeded, if this alarm is assigned to the collective alarm.

The testo 6681 monitors limit values using relays. If a reading is outside the limit values, a relay to be specified by the user is switched.

If the reading reverts to more than a specified hysteresis below or above the limit value, the alarm is cancelled.

In addition, information about the occurrence of error/status messages can be provided by means of a collective alarm relay, see Chapter 1.5 Status, warning and error messages.

If multiple alarm messages are activated at the same time, the last alarm is shown. If the alarm is cancelled again, the previous messages are no longer shown.

Example:

If the condensation of the probe begins, the "Condensation" message appears on the display and the "Start" status display. If the condensation is over, the status display changes from "Start" to "End".

testo 6681 - 1.3 Commissioning

1.3 Commissioning

1.3.1 Assembling the instrument

1.3.1.1 Wall mounting (for testo 6611/6613/6614/6615/6617/6622/6623 probes)

 Attaching rear panel bracket

1 Remove locking screw (item (4) of drawing below) and detach rear

panel bracket from plastic bracket (item (2) of drawing below).

2 Hold rear panel bracket in assembly position and mark the three drill

holes.

3 Drill three holes (∅ 5 mm) and insert dowels where necessary. 4 Screw on rear panel bracket.

Remember that the clamping brackets (1)must face the wall.

testo 6681 - 1.3 Commissioning

 Fastening instrument to rear panel bracket

1 Slide plastic bracket (2) on the back of instrument onto rear panel

bracket until it engages (see arrows).

2 Insert screw (4) through hole (3) and screw into rear panel bracket. 3 Insert probe connector (5) into socket until it engages.

testo 6681 - 1.3 Commissioning

1.3.1.2 Duct mounting (for testo 6612 probes)

1 Hold wall/duct bracket (order no. 0554 6651) (6) against duct wall (8)

and mark drill holes for wall/duct bracket and probe shaft.

2 Drill a hole (∅ 12.5 mm) in the duct wall to feed through the probe

shaft.

3 Fasten wall/duct bracket (6) to duct wall with screws (5). 4 Push probe shaft (9) with filter (10) through the middle hole of the

mounting bracket.

The wall/duct bracket (6) has an O-ring (7) to seal it against the duct. Feed the probe shaft (9) carefully through the wall/duct bracket so that the O-ring is not damaged.

5 Fix the correct position of the probe shaft (9) with screw (11) and mark

(insert probe shaft as far as possible).

6 Slide plastic bracket (2) on the back of the transmitter onto bracket (3,

4) until it engages.

testo 6681 - 1.3 Commissioning

Take the weight of the transmitter into account. Ensure that the brackets (4, 6) are fastened securely.

7 Insert screw (1) through the hole on the top of the instrument and

screw into bracket (3).

8 Insert probe connector (12) into socket until it engages.

1.3.2 Connecting the instrument

 Opening the instrument

1 Loosen screw connection (1) of service flap and open the flap.

testo 6681 - 1.3 Commissioning

2 Loosen and remove housing screws (2). 3 Remove upper part of housing from lower part (3) and place on a

clean surface.

Warning! Electrical voltage. Danger of injury!

De-energize the mains connection before connecting the transmitter!

Only have the transmitter wired and connected by authorized personnel with the voltage disconnected.

1.3.2.1 Overview of terminals

testo 6681 - 1.3 Commissioning

1 Lower part of housing 2 Relay board (option) 3 Relay terminals 4 Insulating trough for relay board 5 Terminal strip for voltage supply

and analog outputs

6 Terminal board

The following description of the terminals refer to this overview and its numbering.

7 Earthing terminal (internal) 8 M 16 x 1.5 screw connection* 9 Earthing terminal (external) 10 M 20 x 1.5 scr ew connection* 11 Eyelet for measuring point panel * Alternatively, NPT cable coupling

or M plug-in connection

testo 6681 - 1.3 Commissioning

1.3.2.2 Connecting voltage supply and analog outputs

Terminal strip for voltage supply and analog outputs, item (5) of Overview of terminals, chapter 1.3.2.1.

1 Feed cable with voltage supply and analog signal lines through opened

M 16 x 1.5 screw connection (item (8) in Overview of terminals, Chapter 1.3.2.1).

2 Strip the cable ends, clamp wire end ferrules on and screw down onto

voltage terminals.

3 Close M 16 x 1.5 screw connection (item (8) in Overview of terminals,

Chapter 1.3.2.1).

Wiring diagram for 2-wire system (4 - 20 mA)

12 to 30

0 V

2 or 3 channels 4 to 20 mA, max. load 100 to 750 Ω

If the channels have to be galvanically isolated, a separate mains unit must be used for each channel.

Wiring diagram for 4-wire system (0 to 20 mA/4 to 20 mA/0 to 1 V/0 to 5 V/0 to 10 V)

CH1

20 to 30 V AC/DC

24V

CH2 CH3

0 V

2 or 3 channels 0 to 20 mA/ 4 to 20 mA/ max. load per 500 Ω

0 to 1 V/0 to 5 V/0 to 10 V

testo 6681 - 1.3 Commissioning

Requirement for the connecting cable of the supply:

• Insulated with cross-section of at least 0.25 sq. mm.

• The supply line must be secured against exceeding 8 A.

• An OFF switch must be installed in an easily accessible

position close by and be marked as such.

1 Feed connection cables of the two, or optionally three, channels

through opened M 16 x 1.5 screw connection (item (8) in Overview of terminals, chapter 1.3.2.1).

2 Strip the cable ends, clamp wire end ferrules on and screw to channel

terminals as shown in diagram.

3 Close M 16 x 1.5 screw connection (item (8) in Overview of terminals,

Chapter 1.3.2.1).

testo 6681 - 1.3 Commissioning

1.3.2.3 Connecting the relay outputs

Only have the transmitter wired and connected by authorized personnel with the voltage disconnected.

Relay terminal strip, item (3) of Overview of terminals, chapter 1.3.2.1

There is the option of twelve terminals for a total of four relays. The designations NC/C/NO (normally closed contact/root or pin/normally open contact) are etched on the surface of the board.

Using PG screw connection

1 Feed connection cables for the relays through opened M 20 x 1.5

screw connection (item (10) of Overview of terminals, chapter 1.3.2.1). 2 Strip cable ends and clamp on wire end ferrules. 3 Connect relays according to chosen function (NC/NO) (see diagrams

below; relay 1 is shown as an example of a connection).

Using plug-in connections (optional)

Only insert or disconnect the plug-in connection when the voltage is disconnected.

4 Clean the connector of the probe line and the coupling of any foreign

matter.

Do not disconnect the connector of the probe line from the instrument for extended periods to protect against contamination.

Connection note

testo 6681 - 1.3 Commissioning

• For the connection, a double-insulated mains cable (sheathed cable) with a cross-section of at least 1.5 sq. mm must be used.

• Cable connection (2) may not be routed in a loop within the tray (1).

• It is recommended that you always tie 3 cores to one another using a cable tie (3).

• The insulation of the cable must be fed at least 5 mm (4) into the tray.

(

)

testo 6681 - 1.3 Commissioning

Use of relay as NC contact (NC = normally closed)

Alarm/status light (example of installation)

250 V AC/DC, 3 A

The busy light (alarm/status light) is permanently on until the relay opens or the circuit is interrupted. This circuit can therefore be used to monitor the functionality of the alarm circuit, as a cable break, for instance, is indicated by the busy light going off.

Use of relay as NO contact (NO = normally open)

Alarm/status light

example of installation

250 V AC/DC, 3 A

testo 6681 - 1.3 Commissioning

The busy light (alarm/status light) only comes on when the relay is switched (closed). Monitoring the functionality of the alarm circuit is therefore not possible with this switching operation.

5 Close M 20 x 1.5 screw connection (item (10) in Overview of terminals,

Chapter 1.3.2.1).

1.3.2.4 Plug-in connection option

As an option, the PG screw connections of the signal and supply lines can be replaced with plug-in connections that are installed at the housing, see Fig. 1 and 2. The relay cabling occurs via standard cable entries and PG screw connections, see Fig. 3 and 4.

Transmitter housing

testo 6681 - 1.3 Commissioning

Plug-in connections for power supply and channels

M12 plug-in connection (5-pin) socket (1) View of the plug-in connections in the installed state from outside

Pin Assignment.

1 V 24 2 V 24 + 3 + Ch 1 4 - Ch 1 5 PE

M12 plug-in connection (5-pin) connector (2)

Pin Assignment.

1 - Ch 2 2 + Ch 2 3 + Ch 3 4 - Ch 3 5 PE

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