Danfoss GD Heavy Duty Data sheet

Data Sheet

Gas detection unit

Heavy duty

Type GD Heavy Duty
Next generation gas detection for industrial refrigeration

The Heavy Duty gas detection units are used
for monitoring and warning of hazardous
Ammonia gas concentrations. They are
intended for ATEX/ IECEx applications and
consists of a robust ameproof metal enclosure
that can be kept closed after wiring, since
programming (conguration) is performed by
magnetic eld to the display via a magnetic
pen.Depending on the application, they are
available with an electrochemical, a
semiconductor or a Pellistor sensor covering a
wide range of ppm.

The Heavy Duty gas detection units are
intended as Stand-alone, or connected to a
central system like Gas Detection Controller
Unit, or a PLC.

As stand-alone the on-board relay can be used
for activation of alarm devices, while the
Analog or RS485 Modbus connection to a
central system allows additional centralized
monitoring and alarm activation.

The gas detection units come with a factory
default, 2-step alarm set-up ready for use. The
integrated software enables the user to
congure two individual alarm ranges. Alarm 1,
a pre-alarm indicating the gas level has passed
a predened threshold 1, and - if the gas level
passes predened threshold 2 - the nal alarm

2.

AI272547483504en-000501

Gas detection unit, Heavy duty

Features

• Digital, factory congured and pre-calibrated gas detectors for plug-and-play installation (no adjustment
required)

• Easy conguration via Display and Magnetic pen and intuitive user-interface; helps simplify operator handling and
minimize risk of operational, settings and calibration errors

• Stand-alone (integrated relay) and/or exible connection to central controller - by either Analog or RS485 open
Modbus communications

• Wide selection of sensor types and detection ranges

• Display background color indicating alarm or communication fault by turning red

• Fieldbus wiring - connect and power up to 96 sensors, wire length max. 900 meters (2953 ft) per segment;
controller expansion modules permits additional segments and alarm relays

• Automatic self-diagnostics to ensure correct communication and operation. On board fault relay

• Sensor seal cap to prevent premature exposure during installation

• Digital user interface ensures high sensor accuracy

• Reduced risk of false alarms due to temperature compensated sensors

• Password protected alarm settings allowing authorized access only

• LCD display with status LED

• Magnetic pen/On-board acknowledge button to reset alarms and to verify that no gas leaks are present

• Service alerts on unit, controller or both, readable via service tool Display

• Quick and precise calibration procedures - either by Plug & Play replacement sensors or calibration with gas

• No potentiometers or multi-meters required

• For improved safety and to optimize the lifetime of the sensor, degenerated sensors with too low sensitivity
(<30%) are rejected during calibration process

• Conformity to Ex d EN60079-0, -1, Ex d IEC 60079-0, -1, EN 50402, EN 61508-1, -2, -3, EN 50271

• Certicate BVS 18 ATEX E 052 X, IECEx BVS 18.0044X

• Enables regulatory compliance with EN 378:2016, ISO 5149:2014, IIAR 2-2017, and ASHRAE 15:2016

© Danfoss | Climate Solutions | 2021.11 AI272547483504en-000501 | 2

Gas detection unit, Heavy duty

Functions

Working principle/Operation

One sensor is connected to the Heavy Duty sensor board via local bus. The Sensor board provides the power supply
of the sensor and prepares the measured data for digital communication.

The operation menu of the Heavy Duty software is accessed through the Display via a Magnetic pen, or the
connected Gas Detection Controller, or via the dedicated GD Service tool (or PC tool). The Service tool (or PC tool) is
plugged directly to the board of the unit by use of an adapter. These interfaces allow the unit conguration, setting
of the unit alarm levels and calibration of the attached sensor.

The service tool (or PC tool) can be used on all units across the Basic, Premium and Heavy Duty platforms.

For Stand-alone units the alarm signals are handled by the unit software, which activates the integrated relay
directly. For central controlled units the alarm signals are handled by the Gas Detection Controller (or a PLC) via the
4-20 mA (2-10V) analog output or the RS485 open Modbus communication.

For additional operational safety the changing of parameters is password protected allowing authorized access
only. The factory default password can easily be customized.

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Sensor

ESC

Sensor

Sensor Type

ppm range

Alarm 1(Alarm relay)

Alarm 2

Hysteresis

Ammonia EC 100

Electrochemical

0 – 100

25 ppm

35 ppm

2 ppm

Ammonia EC 300

Electrochemical

0 – 300

25 ppm

150 ppm

2 ppm

Ammonia EC 1000

Electrochemical

0 – 1000

500 ppm

900 ppm

25 ppm

Ammonia EC 5000

Electrochemical

0 – 5000

1000 ppm

4500 ppm

50 ppm

Ammonia SC 10000

Semiconductor

0 – 10000

5000 ppm

9000 ppm

250 ppm

Ammonia P LEL

Pellistor

0 – 140000 (0 – 100% LEL)

21% LEL (30000 ppm)

21% LEL (30000 ppm)

1% LEL

HC R290/Propane P
5000

Pellistor

0 – 5000

800 ppm

2500 ppm

40 ppm

Details

Description

Power supply

20 – 28 V DC

Power consumption (24 V DC)

90 mA, max. 130 mA

Control unit

Microprocessor with 12 bit converter resolution

Digital

lter

Averaging in order to increase the EMC immunity

Visual indications

2 LEDs for operation, alarm and communication

Gas detection unit, Heavy duty

Product specication

Design

General info

• Cable gland mounted

• Sensor head (SX1) mounted bottom

Figure 1: Heavy Duty

Gas types and thresholds

Table 1: Gas types and thresholds



NOTE:

Hysteresis = 5% of Alarm1 (rounded up to the next higher integer)
Alarm thresholds must be set within 10 to 90% of the sensor range.

Electrical

Table 2: Electrical

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