Alarm, Fault And Active Leds; Power And Inhibit Leds; Internal Sounder - Dräger Regard 3900 Instructions For Use Manual

User information
3.1.4 Under-range
Under-range is displayed when the gas level is below the measuring range (the transmitter signal is below 3.8 mA – but not a
recognized maintenance or fault signal).
0 2 : U n
3.1.5 Maintenance
Maintenance is displayed when transmitter maintenance is due (the transmitter signal is a recognized maintenance signal).
0 2 : M a
3.2

Alarm, fault and active LEDs

WARNING
!
The alarm levels and the activation modes are configured to meet the requirements of the user. The actions and
countermeasures to be taken when any alarm or fault LED activates must be defined by the person responsible for the
gas detection system.
Although there are up to three gas-level alarms (A1 to A3) and two fault alarms (F1 and F2), there are no LEDs on the controller
for alarm A3 or fault F2. Remote warning devices can be configured to provide indications for alarm A3 and fault F2 when
required.
LED
Alarm A1 Flashing
Steady
Off
Alarm A2 Flashing
Steady
Off
Fault F1 Flashing
Steady
Off
Active /
Steady
Blinking (off every 30 sec)
Off
Power and inhibit LEDs
3.3
The power supply to the controller can be from an AC or DC power source or both. When both are used, the DC power source
(usually a battery system) is used as a backup supply in case of AC power supply failure.
Power AC / LED
It is optional to connect this LED when the controller uses both AC and DC power sources. When the LED is connected, it is
illuminated when the controller is supplied from the (primary) AC supply, and is off when the controller is supplied from the
(backup) DC supply.
Power DC / LED
Illuminates when there is a 24 Vdc supply to the internal control modules. (Irrespective of the power supply to the controller, the
internal control modules require a 24 Vdc supply.)
Inhibit / LED
Illuminates to indicate that the alarms are inhibited, and therefore the normal gas-level monitoring and warning functions of
the controller are inactive. When the LED is illuminated, the Active /
30 seconds. Any remote warning device configured to activate when the alarms are inhibited would also activate.
The alarms are inhibited when an internal inhibit switch is set to the maintenance position: usually for maintenance or repair of
the controller.
3.4

Internal sounder

The internal sounder emits an audible warning tone when A1, A2, A3, or F1 activates (not when F2 activates). The sounder also
beeps every 30 seconds when alarms are inhibited.
● Press Acknowledge / OK (or operate the remote reset if available) to silence the sounder.
8
d e r - r a
i n t e n a
Condition
A1 alarm tripped
A1 alarm acknowledged but alarm condition present
No alarm condition
A2 alarm tripped
A2 alarm acknowledged but alarm condition present
No alarm condition
F1 alarm tripped
F1 alarm acknowledged but fault present
Channel healthy
Channel active
Alarms inhibited (see also Inhibit / LED in Section 3.3)
Channel inactive
n g e
n c e
LEDs blink off and the internal sounder beeps every
Regard 3900 Series