Dräger Regard 3900, Инструкция по эксплуатации, Страница: 50 / 292

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_ REGARD
®
3900
_ Description
The series includes the REGARD
®
3900, 3910 and 3920. The REGARD
®
3900 and
3920 are closed wall enclosures; the REGARD
®
3910 is a modular system, which
needs to be installed in a rack-based system. For further information see:
"REGARD
®
3910", page 57.
The control unit monitors the electrical signals from the remote sensor transmitters
to the input channels and emits warning messages if alarm and fault conditions
occur. For each input channel, alarms for up to three different gas concentrations
(A1, A2 and A3) and two fault conditions (F1 and F2) are available. Potentially
dangerous or noxious gases can be displayed on the transmitter by setting alarm
thresholds for the gas concentrations. Depending on the configuration, the alarms
are activated when the monitored concentrations increase or decrease. The faults
(F1 and F2) are triggered when the transmitter emits the corresponding fault signal
(F2 is only used if the transmitter emits a second fault signal). The combination of
internal evaluation module (input modules, relay modules and output modules) as
well as the settings of the control unit can be adapted to the respective gas
detection and warning requirements. In addition, warning devices used with the
control unit can be selected and configured by the user as required. The control unit
of the REGARD
®
3900 series is configured using a Microsoft Windows
®
-based
software programme. The REGARD
®
3920 also features a built-in configuration
menu.
3.2 Intended use
The REGARD
®
3900 control units are used with 4–20 mA transmitters to provide
stationary, continuous monitoring of flammable or toxic gases and vapours as well
as oxygen deficiency or surplus. The control unit is primarily intended for use as
part of a gas detection system, but can be used with each remote sensor
transmitter with 4–20 mA source output. This document describes the REGARD
®
3900 series for use as a control unit for a gas detection system. The control unit is
designed for use in private and public facilities as well as in light industry to provide
the
– Output of measured values via the display.
– Output of visual and acoustic alarm messages at the control unit and external
warning devices.
3.3 Limitations on use
The control unit is not intended or permitted for use in areas where flammable or
explosive gas mixtures can develop.
The control unit cannot be used with 3-wire transmitters with a 4–20 mA sink
output.
3.4 Approvals
With its measuring function for explosion protection, REGARD
®
39x0 is certified
according to Directive 2014/34/EU (EC type examination certificate TÜV 19 ATEX
8400 X). This certification refers to the 4-20 mA signal inputs for measuring
combustible gases. Special conditions for the safe use can be found in the EC type
examination.
ATEX marking: II (2) G