Danfoss DGS Installation guide

Installation Guide

Danfoss Gas Sensor

080R9333

Type DGS

ENGLISH

Technician use only!

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.

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.

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.

AN284527372096en-000301

Regular Test:

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 With DGS-IR it is recommended to do an annual bump test in years without calibration. Check local regulations on calibration or testing requirements. Do not spray or pour pure refrigerant or other liquids onto the sensor head to perform a bump test. This may signiﬁcantly reduce the lifetime of the sensor head or even destroy it. For propane: after exposure to a substantial gas leak, the sensor should be checked by bump test or calibration and replaced if necessary.

Location:

For all gases heavier than air, Danfoss recommends placing the sensor head app. 30cm (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.

Dimensions and appearance

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

Fig. 1

AN284527372096en-000301 | 1

Cable gland opening

Danfoss

148H126_01-2018

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. 2

Danfoss Gas Sensor DGS

GND

AO_01

not used

DI_01

S&H supply

LED Yellow/Green/Red

Sensor 2

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

B&L

open: 19200 Baud closed: 38400 Baud

JP5

JP4

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

WARNING: be very careful not to damage

the internal board components with the screwdriver.

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

80Z790.1

running

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

- 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

Rel. 3

(critical)

Rel. 1

(warning)

Danfoss

BMODBUS A+

24 V AC/D +

Ackn. / Test button / DI_01:

TEST: The button must be pressed for 8 sec.

Tool

JP3

JP2 JP1

not used

- Critical and warning alarm is simulated and AO goes to

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.

Sensor 1

DI_01 (terminals 1 and 2) is a dry-contact (potential-free) behaving identically to the Ackn./Test button.

Remove potential burrs and secure ﬂat surfaces. Install the cable gland according to the enclosed guide.

changing parameters with the Service Tool)

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

Note: For what concern the power supply, please refer to chapter 3.10 Power Con- ditions and Shielding Conceptions in the User Guide (BC291049702513en-000201).

A Class II power supply is recommended

Fig. 3

2 | AN284527372096en-000301

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.

DGS 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 pre-conﬁgured 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.

Action Reaction

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

Reaction Light

RED Fast ﬂashing X (closed)* (open)*

Warning relay 1** SPDT NO (Normally Open)

Critical relay 3** SPDT NC (Normally closed)

AN284527372096en-000301 | 3

+ 5 hidden pages