Danfoss GD Basic, Basic Data sheet

Data Sheet

Gas detection unit

Basic

Type GD Basic and Basic+
Next generation gas detection for industrial refrigeration

The Basic and Basic+ gas detection units are
used for monitoring and warning of hazardous
gas concentrations. They can be used for
detecting commonly used refrigerants.
Depending on the application, they are
available with an electrochemical or a
semiconductor sensor.

The Basic and Basic+ gas detection units are
intended to be connected to a central system
like Gas Detection Controller Unit, or a PLC, by
either Analog or RS485 open Modbus
communications. The central system converts
the alarm signal from the Basic unit to
activation of alarm devices.

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 treshold 1, and - if the gas level
passes predened treshold 2 - the nal alarm 2.

AI272545693488en-000701

Gas detection unit, Basic

Features

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

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

• Flexible connection - by either Analog or RS485 open Modbus communications

• Fieldbus wiring - connect and power up to 96 sensors, wire length max. 900 meter per segment; expansion
modules permits additional segments

• Automatic self-diagnostics to ensure correct communication and operation

• Sensor seal cap to prevent premature exposure during installation

• Digital user interface ensures higher sensor accuracy

• Reduced risk of false alarms due to temperature compensated sensors

• Password protected alarm settings allowing authorized access only

• LED status signals and alarms

• Buzzer & Light option for local audio and visual alarms (Basic+)

• On-board acknowledge button to reset alarms and to verify the 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 EN 50271, EN 61010-1, ANSI/UL 61010 1, CAN/CSA-C22.2 No. 61010-1

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

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Gas detection unit, Basic

Functions

Working principle/Operation

One sensor can be connected to the Basic/Basic+ 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 Basic/Basic+ software is accessed through 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.
The 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.

The alarm signals can be 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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Basic Basic +

Danfoss

148H132_01-2018

Sensor Sensor

Sensor

Sensor Type

ppm range

Alarm 1

Alarm 2

Hysteresis

Ammonia EC 100

Electrochemical

0 – 100 ppm

25 ppm

35 ppm

2 ppm

Ammonia EC 300

Electrochemical

0 – 300 ppm

25 ppm

150 ppm

2 ppm

Ammonia EC 1000

Electrochemical

0 – 1000 ppm

500 ppm

900 ppm

25 ppm

Ammonia SC 1000

Semiconductor

0 – 1000 ppm

500 ppm

900 ppm

25 ppm

HF R1234yf SC 2000 (FR3)

Semiconductor

0 - 2000 ppm

500 ppm

900 ppm

25 ppm

HFC R134A SC 2000 (FR7)

Semiconductor

0 - 2000 ppm

500 ppm

900 ppm

25 ppm

HFC R404A, R507 SC2000

Semiconductor

0 – 2000 ppm

500 ppm

900 ppm

25 ppm

Ammonia SC 10000

Semiconductor

0 – 10000 ppm

5000 ppm

9000 ppm

250 ppm

Ammonia P LEL

Pellistor

0 – 100% LEL

(0 – 140000)

21% LEL

(30000 ppm)

21% LEL

(30000 ppm)

1%

CO2 IR 20000 (2% Vol.)

Infrared

(0 – 2% Vol)

(0 – 20000 ppm

0.5% Vol

(5000 ppm)

0.9% Vol

(9000 ppm)

0.025% vol
(250 ppm)

Details

Description

Power supply

19 – 29 V AC/DC, DC reverse-polarity protected (selected units 100 – 240V AC)

Power consumption (24 V DC)

Max. 250 mA (6 VA)

Gas detection unit, Basic

Product specication

Design

General information

Figure 1: GD Basic and Basic+

• Cable gland not mounted but enclosed

• 4 mounting ears included

• Sensor head mounted bottom right

• Alarm device (Buzzer & Light) mounted bottom left (only Basic +)

Gas types and thresholds

Table 1: Gas types and thresholds

 NOTE:

Hysteresis = 5% of Alarm1 (rounded up to the next higher integer)
LEL/LFL = Lower explosive limit / Lower ammability limit

Electrical

Table 2: Electrical

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