Transmitter Functions; Turning On The Transmitter; Gas Detection; Malfunction - DEGA NB L III LCD RE Series Instruction Manual

Gas detection transmitter
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Transmitter functions

The detector's motherboard is equipped by status LEDs, which help with detecting problems during the installation.
Green LED shines at correct power supply
Yellow LED flashes during sensor warm-up
Red LED shines/flashes in case of malfunction, alarm or substandard situations

1. Turning on the transmitter

After turning on the power the LED "POW" lights up and the LED "ERR" starts flashing, indicating a forming sequence of the
sensor and automatic testing procedures, which can take up to 180s depending on the sensor used. The output voltage of the
current loop is 1mA. During this sequence, testing of internal electronics and stabilization of the sensor in order to eliminate
false alarms after turning on take place. At this time, the display only shows the time until the beginning of the measurement
loop.
After completion of the forming, a 4mA current begins to flow on the output of the current loop and the transmitter starts
working according to its settings.

2. Gas detection

The transmitter continuously measures the detected gas concentration in the atmosphere and converts its current value into a
4-20 mA signal or transmits its value to the evaluation unit via DEGA/MOBUS protocol. The current measured concentration
and alarm status are shown on the display.

3. Malfunction

In case of malfunction the LCD screen displays the measured concentration, an error code and a key symbol
this condition is indicated by the yellow „ERR" LED. The meaning of each error code is explained in Attachment 2.

4. Monitoring the calibration periods

The transmitter continuously checks the calibration validity of the connected sensor.
After 12 months since the last calibration (max. calibration interval) the LED "ERR" starts flashing and an inscription
simultaneously starts flashing on the LCD display. The connected sensor must be calibrated immediately. The
transmitter will transmit the information about the ending calibration via current loop. The transmission will be as follows: 10s
transmitting a 4-20mA signal informing about the current gas concentration followed by a 1 second interval of 2mA current.
5. Reading the record of measured concentrations and alarms
The transmitter periodically, after 60s, stores the current detected concentration into its internal memory. The internal
memory retains data from the last 64260 measurements (cca 44 days). In order to read this information, the program
DegaConfig is required. See the DegaConfig program user manual.

Transmitter controls

A transmitters equipped with an LCD display can be controlled by the magnetic contact located on the sides of the display.
Warning: calibration
1
required
3
Data display
Channel number
5
(address)
7
Calibration icon
9
Measured value
11
Measured value
units
Alarm STEL (short-
13
term exposure limit
exceeded)
15
Alarm indication
6
. On the PCB,
Warning: Service is
2
required
4
Time display
Activated magnetic
6
control
Communication with the
8
control panel in
progress
Bar graph of the
10
measured value
Alarm PEL (long-term
12
exposure limit
exceeded)
14
Alarm level reached

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