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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AI272545693488en-000701 | 2 |
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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AI272545693488en-000701 | 3 |
Gas detection unit, Basic
Product speci€cation
Design
General information
Figure 1: GD Basic and Basic+
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Basic |
Basic + |
Sensor |
Sensor |
•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
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 |
21% LEL |
21% LEL |
1% |
|
(0 – 140000) |
(30000 ppm) |
(30000 ppm) |
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|
|
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CO2 IR 20000 (2% Vol.) |
Infrared |
(0 – 2% Vol) |
0.5% Vol |
0.9% Vol |
0.025% vol |
|
(0 – 20000 ppm |
(5000 ppm) |
(9000 ppm) |
(250 ppm) |
|||
|
|
|
|
|
|
NOTE:
Hysteresis = 5% of Alarm1 (rounded up to the next higher integer) LEL/LFL = Lower explosive limit / Lower „ammability limit
Electrical
Table 2: Electrical
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) |
|
|
© Danfoss | Climate Solutions | 2021.11 |
AI272545693488en-000701 | 4 |
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