Danfoss DGS User guide

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User Guide

Danfoss Gas Sensor Type DGS

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User Guide | Danfoss Gas sensor, type DGS

Contents

1. Intended use ...................................................................................................................................3

2. Introduction ....................................................................................................................................3

3. Installation and maintenance .......................................................................................................3

3.1 Technician use only! ............................................................................................................................................ 3

3.2 Regular Test .......................................................................................................................................................... 3

3.3 Location .................................................................................................................................................................. 3

3.4 Dimensions and appearance ............................................................................................................................ 4

3.5 Cable gland opening ........................................................................................................................................... 4

3.6 Board pinout ......................................................................................................................................................... 4

3.7 Installation instructions ..................................................................................................................................... 5

3.8 Installation Test .................................................................................................................................................... 6

3.9 Troubleshooting ................................................................................................................................................... 7

3.10 Power Conditions and Shielding Conceptions ..............................................................................................7

4. Operation ......................................................................................................................................9

4.1 Function of the keys and LEDs on the keypad .............................................................................................10

4.2 Setting / changing of parameters and set points .......................................................................................10

4.3 Code levels ...........................................................................................................................................................10

5. Menu overview .............................................................................................................................11

5.1 Error status...........................................................................................................................................................12

5.2 Alarm Status ........................................................................................................................................................ 13

5.3 Relay Status ......................................................................................................................................................... 13

5.4 Menu Measuring Values ...................................................................................................................................13

5.5 Display Parameters ............................................................................................................................................14

5.5.1 Software Version ................................................................................................................................... 14

5.5.2 Language ................................................................................................................................................ 14

5.5.3 LCD Function Check .............................................................................................................................14

5.6 Alarm Reset Settings .........................................................................................................................................14

5.6.1 Relay Reset .............................................................................................................................................. 14

5.6.2 Alarm reset duration ............................................................................................................................ 15

5.7 Alarm Settings ....................................................................................................................................................15

5.7.1 Room mode ............................................................................................................................................ 15

5.7.2 Alarm limits ............................................................................................................................................ 15

5.7.3 Alarm relay ............................................................................................................................................. 15

5.8 AO Settings ..........................................................................................................................................................16

5.9 Operating Data ..................................................................................................................................................17

5.10 Calibration ........................................................................................................................................................... 18

5.10.1 Zero calibration ..................................................................................................................................... 19

5.10.2 Gain calibration ....................................................................................................................................20

5.10.3 Zero point calibration of analogue output .....................................................................................21

5.11 Addressing ........................................................................................................................................................... 21

6. MODBUS menu survey .................................................................................................................22

7. Ordering ....................................................................................................................................24

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User Guide | Danfoss Gas sensor, type DGS

1. Intended use This document has the intent to provide the guidelines to avoid possible damages deriving from overvoltage and other possible issues resulting from the connection to the DGS power supply and the serial communication network. Moreover it provides the operations executed via handheld Service Tool. The display of the hand-held Service Tool and the MODBUS interface for integration with Building Management Systems is used as interface for operation, commissioning and calibration of the DGS gas detection unit.

2. Introduction

3. Installation and

maintenance

3.1 Technician use only!

For what concerns display devices, this user guide contains the maximum possible functionality.

Depending on the DGS type some features described here are not applicable and therefore the menu items may be hidden.

Some special features are available via the hand-held Service Tool interface only (not via MODBUS). This includes the calibration routine and certain properties of the sensor head.

This unit must be installed by a suitably qualiﬁed technician who will install this unit in accordance with these instructions and the standards set down in their particular industry/country.

Suitably qualiﬁed operators of the unit should be aware of the regulations and standards set down by their industry/country for the operation of this unit.

These notes are only intended as a guide, and the manufacturer bears no responsibility for the installation or operation of this unit.

Please observe that DGS works as a safety device securing a reaction to a detected high gas concentration. If a leakage occurs, the DGS will provide alarm functions, but it will not solve or take care of the leakage root cause itself.

Failure to install and operate the unit in accordance with these instructions and with industry guidelines may cause serious injury including death, and the manufacturer will not be held responsible in this regard.

It is the installer’s responsibility to adequately ensure that the equipment is installed correctly and set up according to the environment and the application in which the products are being used.

3.2 Regular Test

3.3 Location

To maintain product performance and comply with the local requirements, the DGS must be tested regularly. DGSs are provided with a test button that may be activated to validate the alarm reactions. Additionally, the sensors must be tested by either bump test or calibration. Danfoss recommends the following minimum calibration intervals: DGS-IR: 60 months DGS-SC: 12 months DGS-PE: 6 months

For all gases heavier than air, Danfoss recommends placing the sensor head app. 30 cm (12”) above the ﬂoor and, if possible, in the air ﬂow. All gases measured with these DGS sensors are heavier than air: HFC grp 1, HFC grp 2, HFC grp 3, CO and propane.

For further details on Test and Location please see the Danfoss Application Guide: “Gas detection in refrigeration systems”.

With DGS-IR it is recommended to do an annual bump test in years without calibration. Check local regulations on calibration or testing requirements. For propane: after exposure to a substantial gas leak, the sensor should be checked by bump test or calibration and replaced if necessary.

Danfoss

User Guide | Danfoss Gas sensor, type DGS

3.4 Dimensions and

appearance

Fig. 1

3.5 Cable gland opening

3.6 Board pinout

Fig. 2

Hole punching for cable gland:

1. Select the location for the safest

cable entry

2. Use a sharp screwdriver and a

small hammer

3. Place the screwdriver and

hammer with precision while moving the screwdriver within a small area until the plastic is penetrated.

Fig. 3

open: 0-20mA closed: 0-10V

JP5

not used

LED Yellow/Green/Red

GND

AO_01

DI_01

S&H supply

Continue precision punching with small movements until the round piece can be pulled out with your ﬁngers.

Remove potential burrs and secure ﬂat surfaces.

Install the cable gland according to the enclosed guide.

WARNING: be very careful not to damage the internal

board components with the screwdriver.

Rel. 3

Ackn.-/Test button

(critical)

Rel. 1

(warning)

Danfoss

80Z790.1

BMODBUS

A+

24 V AC/D +

148H126_01-2018

JP4

Sensor 2

Tool

Sensor 1

JP3 JP2 JP1

not used

B&L

open: 19200 Baud closed: 38400 Baud

Note: For what concern the power supply, please refer to chapter 3.10 Power Conditions and Shielding Conceptions.

A Class II power supply is recommended

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User Guide | Danfoss Gas sensor, type DGS

Status LED / B&L:

GREEN is power on.

– ﬂashing if maintenance needed

YELLOW is an indicator of Error.

– the sensor head is disconnected or not the

expected type

– AO conﬁgured as 0 – 20 mA, but no current

is running

– ﬂashing when sensor is in special mode (e.g.

when changing parameters with the Service Tool)

– Supply voltage out of range

RED ﬂashing: is an indication of alarm due to gas concentration level. The Buzzer & Light behaves identical to the status LED.

Ackn. / Test button / DI_01:

TEST: The button must be pressed for 8 sec.

– Critical and warning alarm is simulated and

AO goes to max. (10 V/20 mA), stops on release.

ACKN: If pressed during critical alarm, as default* the relays and Buzzer go out of alarm condition and back on after 5 minutes if the alarm situation is still active.

* the duration and whether to include the relay status with this function or not is user deﬁned. DI_01 (terminals 1 and 2) is a dry-contact (potential-free) behaving identically to the Ackn./Test button.

DC supply for external Strobe & Horn

Whether the DGS is powered by 24 V DC or 24 V AC, a 24 V DC power supply (max. 50 mA) is available between terminals 1 and 5 on connector x1.

Jumpers

* JP4 open → 19200 Baud JP4 closed → 38400 Baud (default)

* JP5 open → AO 0 – 20 mA JP5 closed → AO 0 – 10 V (default)

Note: the DGS must be power cycled before any change to JP4 takes eﬀect.

Analog Output:

If the analog output AO_01 is used (terminals 4 and 5) then you need the same ground potential for the AO and the connected device.

Note: JP1, JP2 and JP3 are not used.

3.7 Installation instructions

The DGS is available with one or two sensors and B&L (Buzzer and Light) as option (see ﬁg. 1). For sensors that can be poisoned by e.g. silicones like all semiconductor and catalytic bead sensors, it is imperative to only remove the protective cap after all silicones are dry, and then energize the device. The sensor protection cap must be removed before taking the DGS into operation

Mounting and wiring

To wall mount the DGS, unscrew the lid by releasing the four plastic screws in each corner and remove the lid. Mount the DGS base to the wall by ﬁtting screws through the holes which the lid screws were fastened by. Complete the mounting by re-applying the lid and fastening the screws. The sensor head must always be mounted so that it points downwards. The DGS-IR sensor head is sensitive to shock – special attention should be paid to protect the sensor head from shocks during installation and operation. Observe the recommended placing of the sensor head as stated on page 1. Extra cable glands are added by following the instruction in ﬁg. 2. The exact position of the terminals for the sensors, alarm relays, digital input and analogue output is shown in the connection diagrams (see ﬁg. 3). The technical requirements and regulations for wiring, electrical security, as well as project speciﬁc and environmental requirements and regulations must be met.

Conﬁguration

For convenient commissioning, the DGS is preconﬁgured and parameterized with factory-set defaults. See Menu Survey on page 5.

Jumpers are used to change the analogue output type and the MODBUS baud rate. See ﬁg. 3. For DGS with Buzzer & Light, alarm actions are given according to following table below.

System integration

To integrate the DGS with a Danfoss system manager or general BMS system, set the MODBUS address using the DGS Service Tool, using password "1234" when prompted. See the DGS User Guide for details on operating the DGS Service Tool. The Baud Rate is adjusted by jumper JP4. As default, the setting is 38.4k Baud. For integration with AK-SM 720/350 change the setting to 19.2k Baud. For more information about data communication see Danfoss document RC8AC--

Sensor replacement

The sensor is connected to the DGS via a plug connection enabling simple sensor exchange instead of an on-site calibration. The internal replacement routine recognizes the exchanging process and the exchanged sensor and re-starts the measurement mode automatically. The internal replacement routine also examines the sensor for actual type of gas and actual measuring range. If the data does not match the existing conﬁguration, the built-in status LED indicates an error. If everything is OK the LED will light up green.

As an alternative, the on-site calibration via the DGS Service Tool can be performed with the integrated, user friendly calibration routine.

See the DGS User Guide for details on operating the DGS Service Tool.

User Guide | Danfoss Gas sensor, type DGS

Action Reaction

Loss of power to DGS OFF OFF X (closed) Gas signal < warning alarm threshold Gas signal > warning alarm threshold Gas signal > critical alarm threshold Gas signal ≥ critical alarm threshold, but ackn. button pressed No alarm, no fault OFF GREEN No fault, but maintenance due OFF GREEN Slow

Sensor communication error OFF YELLOW DGS in special mode OFF YELLOW ﬂashing

Alarm thresholds can have the same value, therefore both the relays and the Buzzer and Light can be triggered simultaneously. The alarm thresholds have a hysteresis of app. 5% * whether to include the relay status with the acknowledge function or not is user deﬁned. ** If the DGS has two sensors and the "Room Mode" is conﬁgured to "2 rooms", then relay 1 acts as a critical

relay for sensor 1 and relay 3 acts as a critical relay for sensor 2. Both relays are SPDT NC. The Buzzer and Light operation is independent of the "Room Mode" setting.

Buzzer

OFF GREEN

OFF RED Slow ﬂashing X (closed)

ON RED Fast ﬂashing X (closed) X (closed)

OFF (ON after delay)

3.8 Installation Test As DGS is a digital device with self-monitoring, all internal errors are visible via the LED and MODBUS alarm messages. All other error sources often have their origins in other parts of the installation. For fast and comfortable installation test we recommend proceeding as follows.

Optical Check

Right cable type used. Correct mounting height according to deﬁnition in the section about mounting. LED status – see DGS trouble shooting.

Reaction Light

RED Fast ﬂashing X (closed)* (open)*

ﬂashing

Warning relay 1** SPDT NO (Normally Open)

Critical relay 3** SPDT NC (Normally closed)

In doing so, the set alarm thresholds are exceeded, and all output functions are activated. It is necessary to check if the connected output functions are working correctly (e.g. the horn sounds, the fan switches on, devices shut down). By pressing the push-button on the horn, the horn acknowledgement must be checked. After removal of the reference gas, all outputs must automatically return to their initial position. Other than the trip testing, it is also possible to perform a functional test by means of calibration. For further information, please refer to the User Guide.

Functional test (for initial operation and maintenance)

Functional test is done by pressing the test button for more than 8 seconds and observing that all connected outputs (Buzzer, LED, Relay connected devices) are working properly. After deactivation all outputs must automatically return to their initial position.

Zero-point test (if prescribed by local regulations)

Zero-point test with fresh outdoor air. A potential zero oﬀset can be read out by use of the Service Tool.

Trip test with reference gas (if prescribed by local regulations)

The sensor is gassed with reference gas (for this you need a gas bottle with pressure regulator and a calibration adapter).

Comparing sensor gas type with DGS speciﬁcation

The replacement sensor speciﬁcation must match the DGS speciﬁcation.

The DGS software automatically reads the speciﬁcation of the connected sensor and compares with the DGS speciﬁcation.

This feature increases the user and operating security.

New sensors are always delivered factorycalibrated by Danfoss. This is documented by the calibration label indicating date and calibration gas. A re-calibration is not necessary during commissioning if the device is still in its original packaging (including air-tight protection by the red protective cap) and if the calibration certiﬁcate has not expired

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oss

80Z875

Busmaster

User Guide | Danfoss Gas sensor, type DGS

3.9 Troubleshooting

3.10 Power Conditions and

Shielding Conceptions

Symptom: Possible cause(s):

LED oﬀ • Check power supply. Check wiring.

• DGS MODBUS was possibly damaged in transit. Check by installing another DGS to conﬁrm the fault.

Green ﬂashing • The sensor calibration interval has been exceeded or the sensor has reached the

end of life. Carry out calibration routine or replace with a new factory calibrated sensor.

Yellow • AO conﬁgured but not connected (only 0 – 20 mA output). Check wiring.

• Sensor type does not match DGS speciﬁcation. Check gas type and measuring range.

• Sensor may be disconnected from printed circuit board. Check to see if the sensor is properly connected.

• The sensor has been damaged and needs to be exchanged. Order replacement sensor from Danfoss.

• Supply voltage out of range. Check power supply.

Yellow ﬂashing • The DGS is set to service mode from the hand-held Service Tool. Change setting

or await time-out within 15 minutes.

Alarms in the absence of a leak

The zero-measurement drifts

• If you experience alarms in the absence of a leak, try setting an alarm delay.

• Perform a bump test to ensure proper operation.

The DGS-SC sensor technology is sensitive to the environment (temperature, moist, cleaning agents, gases from trucks, etc). All ppm measurements below 75 ppm should be disregarded, i.e. no zero-adjustment made.

Standalone DGS without Modbus network communication

Shield/screen is not required for standalone DGS with no connection to a RS-485 communication line. However, it can be done as described in the next paragraph (Fig. 4).

DGS with Modbus network communication in combination with other devices powered by the same power supply

It is strongly recommended to use direct current power supply when:

• more than 5 DGS units are powered by the same power supply

• the bus cable length is longer than 50 m for those powered units

It is moreover recommended to use class 2 power supply (see AK-PS 075)

Make sure to not interrupt the shield when connecting A and B to the DGS (see Fig. 4).

–

A+B

Fig. 4: Loop trough

Shield

Shld

DGS 1 #adr 10 A B Gnd

Danfoss Modbus

device

Fig. 5: Wiring diagram for system with one power supply

Danf

AK-PS 075 power supply

DGS 2 #adr 11 A B Gnd

1 KΩ

DGS n #adr xx A B Gnd

–

Input 230 V

230 V

Danfoss

80Z876

Ground potential diﬀerence between nodes of the RS485 network might aﬀect the communication. It is advised to connect a 1 KΩ 5% ¼ W resistor between the shield and the ground (X4.2) of any unit or group of units connected to the same power supply (Fig. 5). Please refer to Literature No. AP363940176099.

Busmaster

User Guide | Danfoss Gas sensor, type DGS

DGS with Modbus network communication in combination with other devices powered by more than one power supply

It is strongly recommended to use direct current power supply when:

• more than 5 DGS units are powered by the same power supply

• the bus cable length is longer than 50 m for those powered units It is moreover recommended to use class 2 power supply (see AK-PS 075)

Make sure to not interrupt the shield when connecting A and B to the DGS (see Fig. 4).

1 KΩ

Shield

DGS 1 #adr n1 A B Gnd

Shield

DGS 1 #adr n11 A B Gnd

AK-PS 075 power supply

DGS 2 #adr n2 A B Gnd

DGS 2 #adr n12 A B Gnd

DGS n #adr nx A B Gnd

DGS n #adr ny A B Gnd

–

AK-PS 075 power supply

–

230 V

Danfoss

Modbus

device AK-SM

Shld

Busslave

230 V

Danfoss

Modbus

device AK-CC

Shld

Fig. 6: Wiring diagram for system with multiple power supplies

Power supply and voltage alarm

The DGS device goes into voltage alarm when voltage exceeds certain limits. The lower limit is 16 V. The upper limit is 28 V, if DGS software version is lower than 1.2 or 33.3 V in all other cases. When in the DGS the voltage alarm is active, in the System Manager the “Alarm inhibited” is raised.

Danfoss

80Z878

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Gas Det ection Service Tool

Esc

←─

User Guide | Danfoss Gas sensor, type DGS

4. Operation The conﬁguration and service is made via the hand-held Service Tool or in combination with the MODBUS interface.

Security is provided via password protection against unauthorized intervention.

Hand-held Service Tool:

Operation is done via 6 buttons.

AK- System Manager:

The conﬁguration is done via the graphical display and buttons or via the PC tools StoreView Desktop or AK-ST 500.

D1 R744 ppm Warm-up Time

DGS Service Tool

Operation with the hand-held Service Tool is described in sections 4.1 – 4.3 and chapter 5. Operation with the Danfoss Front End is described in chapter 6.

Two functions are conﬁgured via jumpers on the DGS.

Jumper 4, JP 4, located at the bottom left, is used to conﬁgure the MODBUS baud rate. As default the baud rate is 38400 Baud. By removing the jumper, the baud rate is changed to 19200 Baud. Removing the jumper is required for integrating with Danfoss System Managers AK-SM 720 and AK-SM 350.

Jumper 5, JP5, located at the top left, is used to conﬁgure the analogue output type. As default this is voltage output. By removing the jumper, this is changed to current output.

Note: the DGS must be power cycled before any change to JP4 takes eﬀect. JP1, JP2 and JP3 are not used.

Ackn.-/Test button

Rel. 3

(critical)

Rel. 1

(warning)

Danfoss

80Z790.1

BMODBUS A+

24 V AC/D +

open: 0-20mA closed: 0-10V

JP5

GND

AO_01

not used

DI_01

S&H supply

LED Yellow/Green/Red

B&L

JP4

open: 19200 Baud closed: 38400 Baud

Sensor 2

Tool

Sensor 1

JP3 JP2 JP1

not used

User Guide | Danfoss Gas sensor, type DGS

4.1 Function of the keys and

LEDs on the keypad

4.2 Setting / changing of

parameters and set points

ESC

The status LEDs indicate the operating status:

• Green

• Yellow

• Red Continuous = alarm

The backlight of the display changes from green to red when an alarm is active.

Exits programming, returns to the previous menu level.

Enters sub menus, and saves parameter settings.

Scrolls up & down within a menu, changes a value.

Change of cursor position.

Continuous = operating voltage

Continuous = failure Slowly ﬂashing = warming-up Fast ﬂashing = special mode

Open desired menu window. Code input ﬁeld opens automatically if no code is approved.

After input of valid code, the cursor jumps to the ﬁrst position segment to be changed.

Push the cursor to the position segment, which has to be changed.

Set the desired parameter / set point with the keys.

Save the changed value, conﬁrm storage (ENTER).

ESC

4.3 Code levels All inputs and changes are protected by a four-digit numeric code (= password) against unauthorised

intervention according to the regulations of all national and international standards for gas warning systems. The menu windows of status messages and measuring values are visible without entering a code.

The access to the protected features is valid as long as the service tool remains connected.

The service technician’s access code to the protected features is ‘1234’.

Cancel the save / close editing / return to a higher menu level (ESCAPE function).

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User Guide | Danfoss Gas sensor, type DGS

5. Menu overview

Menu operation is done via a clear, intuitive and logical menu structure. The operating menu contains the following levels:

• Starting menu with indication of the device type if no sensor head is registered, otherwise scrolling display of the gas concentrations of all registered sensors in 5-second intervals.

• Main menu

• 5 sub menus under “Installation and Calibration”

Power On Time

19 sec.

Seconds indicator = 0

Danfoss

DGS

After about 2 seconds

1 R744 ppm

Warm-up Time

Power On Time of the basic device Count down in seconds until the communication between the hand-held Service Tool and the DGS is established. In case of communication error the countdown will stop.

“Warm-up Time” is displayed. As soon as the sensor warm-up time has expired, the measured value is displayed = measuring mode. When the warm-up time has expired, the display will show the measurement value - see section 4.4. Note: with 2 sensor variants the screen will alternate between the two sensors every 5 seconds.

Start menu

Main menu

Error Status

Alarm Status

Relay

Status

Measuring Values

Display

Parameters

Reading and acknowledgement of errors. See chapter 5.1

Display of the status of active alarms. See chapter 5.2

Display of the relay status. Protected by password. See chapter 5.3

Display of measuring values. See chapter 5.4

Read-out of hand-held tool version, language and set-up of language. Partly protected by password. See chapter 5.5

Installation &

Calibration

Reading and change of the relay, sensor head and system parameters as well as test and calibration functions.

User Guide | Danfoss Gas sensor, type DGS

Menu overview

(continued)

Start menu

Main menu

Service OFF

The following menu items are only accessible with Service ON (password protected)

!! Service ON = special mode = fault message is active!!

Alarm reset settings

Alarm settings

AO Settings

See chapter 5.6

See chapter 5.7

See chapter 5.8

Operating Data

Calibration

Addressing

5.1 Error status A pending fault activates the yellow LED (Fault). The ﬁrst 50 pending errors are displayed in the menu “System Errors“.

A number of error messages may be displayed related to the sensor: Out of Range, Wrong type, Removed, Calibration due, Voltage Error. “Voltage Error” refers to the supply voltage. In this case the product will not go into normal operation until the supply voltage is within the speciﬁed range.

See chapter 5.9

See chapter 5.10

See chapter 5.11

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User Guide | Danfoss Gas sensor, type DGS

5.2 Alarm Status Display of the currently pending alarms in plain text in the order of their arrival. Only those sensor

heads are displayed, where at least one alarm is active.

Alarms in latching mode (latching mode is only valid for certain DGS types, DGS-PE) can be acknowledged in this menu (only possible if the alarm is not active).

Alarm Status

Symbol Description Function

DP 1 Sensor head No.

‘A1 ‘‘A1

Alarm status

DP 1 “A1

5.3 Relay Status Reading of the current status of alarm relays. The actual relay status is displayed, depending on the relay mode (energized <> de-energized). Selection of alarm relay:

Alarm Relay Status

Alarm Relay 1 Status OFF

Selection of the next alarm relay

Symbol Description Function

1 Alarm Relay

OFF Relay Status Relay OFF = coil de-energized

ON Relay Status Relay ON = coil energized

Note: Relay 3 is used for critical alarm indication. Relay 1 may be conﬁgured for critical alarm indication with the 2-sensor variant. A critical alarm relay has a Normally Closed contact set which indicates an alarm if the power to the DGS is lost. In the table above the relays status refers to energizing of the coil, which activates the contact set. Hence, for a critical relay in normal operation the coil is energized, causing the contact set to open and the relay status to read “ON”. In the alarm condition, the coil is de-energized, causing the contact set to close and the relay status to read “OFF”.

Gasfree state ascertained?

DP 1: Sensor 1 DP 2: Sensor 2 (2-sensor variant only)

‘ = Alarm active ‘’ = Alarm in latching mode, can be acknowledged 1 = Relays 1 = Warning relay 3 = Relay 3 = Critical relay

1 = Relays 1 = Warning relay 2 = Buzzer 3 = Relay 3 = Critical relay

5.4 Menu Measuring Values

In this menu, the display shows the measuring value with gas type and unit.

Measuring Values 1 R744 ppm

A ! 450

Selection of the next sensor head

Symbol Description Function

1 Actual MODBUS address 1: MODBUS address = 1

R744 Gas type Display of gas type (must comply with gas type of sensor head)

ppm Gas unit Unit

51.0 °C Measured value Current value of the gas concentration

A! Alarm indication At least one alarm has been released at this sensor head

# Maint. info Sensor head: maintenance due (maintenance date exceeded)

? ConﬁgError Gas type or meas. range does not comply with sensor head

Comm. err. Fault sensor head Communication error, sensor head <> I/O board

Underrange Overrange

Warm-up Warm-up time Warm-up time of the sensor is active

Meas. range monitoring

Meas. signal < admissible range (< zero point – 6 %) Meas. signal > admissible range (> full scale value + 6 %)

AO Value

10.0 V 20.00 mA

The actual analogue output value in voltage and milliampere.

User Guide | Danfoss Gas sensor, type DGS

5.5 Display Parameters In the menu display parameters you can ﬁnd the general parameters of the Service Tool and the DGS.

Display Parameters

5.5.1 Software Version

Software Version XXXXX - YYYYY

Software version of the hand-held Service Tool and of the DGS.

Symbol Description Function

XXXXX Software Version of the Service Tool XXXXX Software Version

YYYYY Software Version of the DGS YYYYY Soft ware Version

5.5.2 Language

Language English

Selection of the menu language (password protected)

Symbol Description Default Function

English

English Language English

Spanish French Italian German

5.5.3 LCD Function Check Function for testing the LCD function (password protected) All LEDs light up for about two seconds.

The backlight is yellow. All points are displayed on the LCD.

LCD Function check?

5.6 Alarm Reset Settings This section describes how the DGS reacts when an active alarm is reset (acknowledged).

Alarm Reset Settings

5.6.1 Relay Reset This deﬁnes if the relay resets to “no alarm condition” state when a critical alarm is reset (acknowledged).

Symbol Description Default Function

Relay Rst Enable

Function ON ON = Relays reset when an active alarm is reset

(acknowledged).

OFF = The alarm relay remains active even if the alarm is acknowledged (it is useful to keep ventilation system running until concentration is below the alarm threshold).

Relay Rst Enable ON

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User Guide | Danfoss Gas sensor, type DGS

5.6.2 Alarm reset duration This deﬁnes how long the alarm reset is active (alarm acknowledged).

Time 300

Symbol Description Default Function

Reset Alarm Time

Relay Rst Enable Function

300 Deﬁnes how many seconds the alarm reset condition

is active. If the alarm condition has not cleared within this time, the alarm will be re-activated without any further delay (Buzzer, and if conﬁgured, also the relay)

0: The alarm reset function is disabled.

5.7 Alarm Settings

5.7.1 Room mode

5.7.2 Alarm limits

Reading and changing (only via code level 1) of Alarm Settings.

MP 1 active

Warning limit C 5000 ppm

This function is only available for measuring point 2 (MP2). It deﬁnes if the sensors share the critical relay and the warning relay (both sensors mounted in same room) or each sensor has 1 critical relay each (two rooms with one sensor).

In the menu structure, this setting is accessible under sensor 2 only (MP2).

Room Mode 1 Room

Symbol Description Default Function

Room Mode Function 1 Room 1 Room: Relay 1 is used as warning relay for both

For each sensor head two alarm thresholds are available for free deﬁnition. If the gas concentration is higher than the set alarm

sensors and relay 3 is used as critical relay for both sensors.

2 Rooms: Relay 1 is used as a critical relay for sensor 1 and relay 3 is used as critical relay for sensor 2.

Warning limit C 5000 ppm

threshold, the associated alarm is activated. If the gas concentration falls below the alarm threshold inclusive hysteresis, the alarm is reset again.

The hysteresis of both alarm is 5% of the default alarm threshold (e.g. with 5000 ppm this

Critical limit C 5000 ppm

corresponds to 250 ppm).

Note: With propane (R290), the alarm status will not auto-clear if the measured ppm-value has exceeded the max-range of the sensor element. In this case the concentration may be as indicated OR it may still be above the max-range. The alarm must be manually cleared and the room checked before entry.

Delay Alarm ON 0 sec.

5.7.3 Alarm relay

For setting the alarm delay for Critical and Warning alarms.

Symbol Description Default Function

0 sec. Delay Alarm 0 sec.

Gas concetration > alarm threshold + set time = Alarm ON Gas concentration < alarm threshold – hysteresis = Alarm OFF

User Guide | Danfoss Gas sensor, type DGS

5.8 AO Settings

AO Settings

Analog Output 1

50% -- min = 0 V.

This menu is for the conﬁguration of the analogue outputs.

If more than one sensor head is present, the maximum value of the two measurements is assigned to the output.

Using this function, it is possible to conﬁgure the output signal.

The CO sensor with a range of 0 – 20000 ppm has an output signal of 0 – 10 V corresponding to 0 – 10000 ppm as default.

As an example this may be changed to e.g. 2 – 10 V for 0 – 20000 ppm by changing settings to “100%” and “2 V ”.

Symbol Description Default Function

50% 100%

- -

0 V 2 V

Selection of the ppm measurement which will give the maximum output signal

DANFOSS ONLY SETTING

Selection of minimum output signal

50%

0 V

50% = at a concentration of 50% of the sensor head range the output will be set to 10 V (20 mA without JP5 mounted) 100% = at a concentration of 100% of the sensor head range the output will be set to 10 V (20 mA without JP5 mounted)

Do not change – If doing so, a small “noise signal” (step form) on top of the measured ppm value with a duty cycle of app. 180s is activated.

0 V = at the minimum measuring signal of the sensor, the output will be set to 0V (0 mA without JP5 mounted) 2 V = at the minimum measuring signal of the sensor, the output will be set to 2 V (4 mA without JP5 mounted)

The analogue output signal depends on above settings and the conﬁguration of jumper JP5. The output signal is continously monitored by the DGS. If the value deviates by more than 5% from the expected value, an Error Message is generated. This might happen if the output is short-circuited. If conﬁgured for current output (JP5 open) the alarm is also generated if the output is open-circuited. In below examples, it is assumed that the output is in voltage (JP5 closed) and that a 0 – 20000 ppm sensor is used.

The analogue output signal, AO is calculated by this formula:

ppm value

AO =

ppm range

x AO range + AO min.

Example 1 (default settings):

“AO output max. scaling” = 50% “AO min. value” = 0 (default)

This means that in the formula:

• AO range = 10 V

• AO min. = 0 V

• ppm range = 10000 ppm

Hence, a measured value of 4000 ppm will result in the following output value:

4000 ppm

AO = x 10 V + 0 V = 4 V

10000 ppm

Example 2:

“AO output max. scaling” = 100% “AO min. value” = 2 V

This means that in the formula:

• AO range = 8 V

• AO min. = 2 V

• ppm range = 20000 ppm

Hence, a measured value of 4000 ppm will result in the following output value:

4000 ppm

AO =

20000 ppm

x 8 V + 2 V = 3.6 V

16 | BC291049702513en-000201 © Danfoss | Climate Solutions | 2022.01

User Guide | Danfoss Gas sensor, type DGS

5.9 Operating Data

This menu is for retrieving relevant operational data from the sensor head. No changes or modiﬁcations are possible.

Operating Data

Operating Data SC

If more than one sensor head is connected to the DGS, the selection is done at X.

Operating Data SC X

Software version XXXX

Days of Operation X Days

Software version of the sensor head.

Current days of operation.

Days of Operation expected XXX

Min. Temperature 25 °C

Max. Temperature 25 °C

Number of Calib. X

Sensitivity XXX%

Days of Operation Last XXX

Expected remaining lifetime (in days) of the sensor head.

Display of the lowest temperature detected by the device.

Display of the highest temperature detected by the device.

How many times the sensor head has been calibrated.

Remaining sensitivity of the sensor. Must be replaced when below 35%. The value is only updated immediately after calibration.

Days of operation since the last calibration took place.

Maintenance Days remaining XXXX

Days until the next calibration is due.

User Guide | Danfoss Gas sensor, type DGS

5.10 Calibration

This section gives an overview of the calibration menu. The calibration description can be found on the following pages. For HFC, remember to use the speciﬁed calibration gas. (HFC grp 1 = R1234yf, grp 2 = R134a, grp 3 = R407c)

Calibrate

DP 1 Sxxx R744 ppm

Selection of the

sensor head to

be calibrated

Zero DP 1

Calibration gas

XXXX ppm

Gain DP 1

Zero calibration. See section 4.10.1

Set the test gas concentration.

Gain calibration. See section 4.10.2

Calibration AO 1

Burn clean

See section 4.10.3

Only available for combustible gases (propane).

User Guide | Danfoss Gas sensor, type DGS

5.10.1 Zero calibration

The stepwise calibration process is described below. Note: The speciﬁed warm-up times etc. must be strictly observed before starting the calibration process.

Zero DP 1

100 ppm

Zero DP 1

90 ppm

Step 1: Display of the current value. Step 2: Apply test gas according to instructions. Step 3: Start calibration process.

Step 4: Calculation of the new zero point. During calculation an underscore in line two runs from left to right and the current value drops to zero.

Step 5: When the current value is stable, press for ﬁnishing the calculation of the new value.

Zero DP 1

SAVE

Zero DP 1

0 ppm 

Step 6: Save the newly calculated zero point. “SAVE“ is displayed, as long as the function is executed.

After the value has been successfully stored, a square appears on the right for a short time = zero point calibration is ﬁnished and new zero oﬀset has been stored with success.

Zero DP 1

0 ppm

The display automatically goes to step 1: Display of new zero point.

During the calculation phase, the following messages may occur:

Message Description

Current value too high Wrong gas for zero point calibration or sensor element defective. Replace sensor head.

Current value too small Wrong gas for zero point calibration or sensor element defective. Replace sensor head

Current value unstable

Time too short

Internal error

Appears when the sensor signal does not reach the zero point within the target time. Disappears automatically when the sensor signal is stable.

The message “value unstable” starts an internal timer. Once the timer has run out and the current value is still unstable, the text is displayed. The process starts over again. If the value is stable, the current value is displayed and the calibration procedure is continued. If the cycle is repeated several times, an internal error has occurred. Stop the calibration process and replace the sensor head.

Calibration is not possible → check if burning clean process is completed or interrupt it manually or check/replace sensor head.

If aborting the zero oﬀset calibration, the oﬀset value will not be updated. The sensor head continues to use the “old” zero oﬀset. A full calibration routine must be conducted to save any calibration change.

User Guide | Danfoss Gas sensor, type DGS

5.10.2 Gain calibration

The stepwise calibration process is described below. Note: The speciﬁed warm-up times etc. must be strictly observed before starting the calibration process.

Test Gas

XX.X ppm

Enter concentration of the test gas used. This value is not cleared when exiting the menu, therefore always check if the value is correct before calibrating.

Gain DP 1

Gain DP 1 100 ppm 100%

Step 1: Display of the current value and of the sensitivity from the last calibration. Step 2: Apply test gas according to instructions. Step 3: Start calibration process.

Gain DP 1 _90 ppm

Step 4: Calculation of the new gain. During calculation an underscore in line two runs from left to right and the current value converges to the set test gas concentration. The sesitivity is recalculated, too.

Step 5: When the current value is stable, press for ﬁnishing the calculation of the new value.

Gain DP 1

SAVE

Step 6: Save the newly calculated gain. ‘SAVE‘ is displayed as long as the function is executed.

Gain DP 1

0.0 ppm 

Gain DP 1

After the value has been successfully stored, a square appears on the right for a short time = Gain calibration is ﬁnished and new gain oﬀset has been stored with success.

The display automatically goes to step 1: Display

0.0 ppm

During the calculation phase, the following messages may occur:

Message Description

Current value too high

Current value too low No test gas or wrong test gas applied to the sensor.

Test gas too high Test gas too low

Current value unstable

Time too short

Sensitivity < Sensitivity of the sensor head < 30%, calibration no longer possible → replace sensor head.

Internal error

Test gas concentration > than set value Internal error → replace sensor head

The set test gas concentration must be between 30% and 90% of the measuring range.

Appears when the sensor signal does not reach the calibration point within the target time. Disappears automatically when the sensor signal is stable.

Calibration is not possible → check if burning clean process is completed or interrupt it manually or check/replace sensor head.

User Guide | Danfoss Gas sensor, type DGS

5.10.3 Zero point calibration of

analogue output

With this menu item you can adjust the zero point of the analogue output (4mA). The zero point correction is only possible when the minimum output is 2 V or 4 mA, i.e. not possible when minimum output is 0 V or 0 mA.

The error message of the output monitoring is suppressed as long as the menu Calibration AO is open. Therefore, connect the ampere meter (measuring range 20 mA DC) to the analogue output only after having opened the menu.

Calibration AO 1

Connect ampere meter to the analogue output.

Calibration AO 1

Display of the current zero oﬀset on the left.

320 0

Calibration AO 1 320 323

Calibration AO 1

Adjust the zero oﬀset on the right by changing the oﬀset value slowly, until the ampere meter shows the desired value.

Save the adjusted zero oﬀset.

SAVE

Calibration AO 1

Return to the display of the current zero oﬀset.

323 323

5.11 Addressing

Addressing

Assignment of the MODBUS address of the device for system integration, e.g. with Danfoss front end type AK-SM 800.

Set Address

Deﬁne the MODBUS address.

Symbol Description Default Function

4 MODBUS Address 0 0 = Device is not addressed, BUS not used. Max. value is 240.

User Guide | Danfoss Gas sensor, type DGS

6. MODBUS menu survey

Function Min. Max. Factory Unit AKM name

Gas level

Sensor 1 Actual gas level in % of range 0.0 100.0 - % Gas level %

Sensor 1 Actual gas level in ppm 0 FS1 - ppm Gas level ppm

Sensor 2 Actual gas level in % of range 0.0 100.0 - % 2: Gas level %

Sensor 2 Actual gas level in ppm 0 FS1 - ppm 2: Gas level ppm

Alarms Alarm settings

Indication of critical alarm (critical alarm of Gas 1 or Gas 2 active) 0: No active alarm(s) 1: Alarm(s) active

Common indication of both critical and warning alarm as well as internal and maintenance alarms 0: No active alarm(s), warning(s) or errors 1: Alarm(s) or warning(s)) active

Gas 1 Critical limit in %. Critical limit in % (0-100)

Gas 1 Critical limit in ppm Critical limit in ppm; 0: Warning Signal deactivated

Gas 1 Warning limit in % (0-100) 0 100.0 HFC: 25

Gas 1 Warning limit ppm 0: Warning Signal deactivated

High (critical and warning) alarm delay in seconds, if set to 0: no delay 0 600 0 sec. Alarm delay s

When set to 1, the Buzzer is reset (and the relays if deﬁned: Relay rest enable) to no alarm indication. When the alarm is reset or the time-out duration is exceeded, the value is reset to 0. Note: The alarm condition is not reset - only the output indication is reset. 0: Alarm outputs not reset 1: Alarm outputs reset–Buzzer muted and relays reset if conﬁgured

Duration of alarm reset before automatic re-enable of alarm outputs. A setting of 0 disables the ability to reset alarm.

Relay reset enables: Relay reset with alarm acknowledge function 1: (default) Relays wil be reset if the alarm acknowledge function is activated 0: Relays remain active until the alarm condition clears

Gas 2 Critical limit in %. Critical limit in % (0-100)

Gas 2 Critical limit in ppm Critical limit in ppm; 0: Warning Signal deactivated

Gas 2. Warning limit in % (0-100) 0 100.0 CO: 25 % 2: Warn. limit %

Gas 2. Warning limit ppm 0: Warning Signal deactivated 0.0 FS1 CO: 5000 ppm 2: Warn. limit ppm

High (critical and warning) alarm delay in seconds, if set to 0: no delay 0 600 0 sec. 2: Alarm delay s

Conﬁguration of relays for one or two rooms’ application mode. 1: One room with two sensors sharing the same warning relay and critical relay 2: Two rooms with one sensor in each, and each sensor having a critical alarm relay. In this mode, warning alarms activate as normal on the LED indicator, hand-held Service Tool and on MODBUS.

Service

Status of the sensors’ warm-up period 0: Ready 1: Warming up one or more sensors

0 1 - - GD alarm

0 1 - - Common errors

0.0 100.0 HFC: 25 CO: 25 R290: 16

0 FS1 HFC: 500

CO: 5000 R290: 800

CO: 25 R290: 16

0.0 FS1 HFC: 500 CO: 5000 R290: 800

0 1 0 - Reset alarm

0 9999 300 sec. Reset alarm time

0 1 1 - Relay rst enable

0.0 100.0 CO: 25 % 2: Crit. limit %

0 FS1 CO: 5000 ppm 2: Crit. limit ppm

1 2 1 - 2: Room Mode

0 1 - - DGS Warm-up

% Crit. limit %

ppm Crit. limit ppm

% Warn. limit %

ppm Warn. limit ppm

) The max. alarm limit for CO is 16.000 ppm / 80% of full scale. All other values equal the full scale range of the speciﬁc product.

User Guide | Danfoss Gas sensor, type DGS

Readout the attached gas sensor type. 1: HFC grp 1

R1234ze, R454C, R1234yf R1234yf, R454A, R455A, R452A R454B, R513A

2: HFC grp 2

R407F, R416A, R417A R407A, R422A, R427A R449A, R437A, R134A R438A, R422D

3: HFC grp 3

R448A, R125 R404A, R32 R507A, R434A R410A, R452B

R407C, R143B 4: CO 5: Propane (R290)

Full scale range 0 32000 HFC: 2000

Gas 1 Days until next calibration 0 32000 HFC: 365

Gas 1 Estimates how many days remaining for sensor 1 0 32000 - days Rem.life time

Status of the critical alarm relay: 1: ON = no alarm signal, coil under power - normal 0: OFF = alarm signal, coil depowered, alarm situation

Status of the warning relay: 0: OFF = inactive, no warning active 1: ON = active warning, coil under power

Status of the Buzzer: 0: inactive 1: active

Gas 2 Days until next calibration 0 32000 HFC: 365

Gas 2 Estimates how many days remaining for sensor 2 0 32000 - days 2: Rem.life time

Activates a mode which simulates an alarm. Buzzer, LED and relays all activate. 1:-> Test function - no alarm generation possible now Automatically falls back to Oﬀ after 15 min. 0: back to normal mode

Analogue output max. scaling 0: zero to full scale (e.g (Sensor 0 – 2000 ppm) 0 – 2000 ppm will give 0 – 10 V) 1: zero to half scale (e.g (Sensor 0 – 2000 ppm) 0 – 1000 ppm will give 0 – 10 V)

Analogue output min. value 0: select 0 – 10 V or 0 – 20 mA output signal 1: select 2 – 10 V or 4 – 20 mA output signal

Alarms

Critical Limit alarm 0: OK 1: Alarm. Gas limit exceeded and delay expired

0: OK 1: Fault. Out of range under test – over range or under range

0: OK 1: Fault. Sensor and head failures

0: OK 1: Fault. Sensor out or removed, or wrong sensor connected

0: OK 1: Warning. Due for calibration

0: OK 1: Warning. Gas level above warning level and delay expired

Indication if the normal alarm function is inhibited or in normal operation: 0: Normal operation, i.e. alarms are created and cleared 1: Alarms inhibited, i.e. alarm status is not updated, e.g. due to DGS in test mode

1 5 N - Sensor type

CO: 20000 R290: 5000

CO: 1825 R290: 182

0 1 - - Critical Relay

0 1 - - Warning Relay

0 1 - - Buzzer

CO: 1825 R290: 182

0 1 0 - Test Mode

0 1 HFC: 1

CO: 1 R290: 0

0 1 0 - AOmin = 2V/4mA

0 1 - - Critical limit

0 1 - - Out of range

0 1 - - Wrong SensorType

0 1 - - Sensor removed

0 1 - - Calibrate sensor

0 1 - - Warning limit

0 1 - - Alarm inhibited

ppm Full scale ppm

days Days till calib

days 2: Days til calib.

- AOmax = half FS

Critical Limit alarm

0 1 - - 2: Criti. limit 0: OK 1: Alarm. Gas limit exceeded and delay expired

0: OK

0 1 - - 2: Out of range 1: Fault. Out of range under test – over range or under range

0: OK

0 1 - - 2: Wrong SensType 1: Fault. Sensor and head failures

0: OK

0 1 - - 2: Sens. removed 1: Fault. Sensor out or removed, or wrong sensor connected

0: OK. Sensor not due for calibration

0 1 - - 2: Calibrate sens. 1: Warning. Due for calibration

0: OK

0 1 - - 2: Warning limit 1: Warning. Gas level above warning level and delay expired

7. Ordering

DGS Sensors Spares and accessories

Product Description Code no. Product Description Code no.

DGS-SC H FC grp 1* 080Z2803 Spare sensor HFC grp 1* Spare 080Z2815

DGS-SC H FC grp 2* 080Z2804 Spare sensor HFC grp 2* Spare 080Z2816

DGS-SC H FC grp 3* 080Z2805 Spare sensor HFC grp 3* Spare 080Z2817

DGS-PE propane 080Z2806 Spare sensor propane Spare 080Z2818

DGS- IR CO 080Z2800 Spare sensor CO Spare 080Z2813

DGS- IR CO 5 m 080Z2801 Spare sensor CO - 5 m Spare 080Z2814

DGS-IR 2 * CO - 5 m 080Z2802 Hand-held Service Tool Accessory 080Z2820

DGS-SC H FC grp 1* + B&L 080Z2809 Strobe & Horn Accessory 080Z2819 DGS-SC H FC grp 2* + B&L 080Z2810 Splash guard Accessory 148H6226 DGS-SC H FC grp 3* + B&L 080Z2811 Duct se t Accessory 148 H6236 DGS-PE propane + B&L 080Z2812 Calibration adaptor Accessory 148 H6232 DGS- IR CO + B&L 080Z2807 Remote kit Accessory 148H6238 DGS- IR CO 5 m + B&L 080Z2808 Power Supply AK-PS075 Accessory 080Z0053

* HFC grp 1: R1234ze, R454C, R1234y f, R454A, R455A, R452A, R454B, R513A HFC grp 2: R407F, R416A, R417A, R407A, R422A, R427A, R449A, R437A, R134 A, R438A, R422D HFC grp 3: R448A, R125, R404A, R32, R507A, R434A, R410A, R452B, R407C , R143B

Bold = calibration gas

Note: DGS is also available for alternative refrigerant gases on request. Please contact your local Danfoss sales oﬃce for details.

Danfoss DGS User guide

Specifications and Main Features

Frequently Asked Questions

User Manual