LumaSense Technologies INNOVA 1412i - Manual (Page 69)

Chapter 5
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BE6025-15 1412i Photoacoustic Gas Monitor LumaSense Technologies A/S
Page 69 of 202
5.5 Alarm Relay
Two alarm relays are built into the alarm relay socket on the
back panel of the Monitor. The function of the pins in this female
connector is shown in Fig.5.2 . The two alarm relays can be
connected to a variety of either audio (for example, a siren)
and/or visual (for example a flashing light) alarm systems and
they are activated whenever a pre-defined concentration (alarm
level) of one (or more) of the gases being measured is exceeded.
Alarm signals are given by opening and closing the relay contacts.
Both relays are closed when the Monitor is switched off and when
the Monitor is switched on. This means that there is a direct
electrical connection between pins 1 & 2 and pins 4 & 5 at all
times except when the Monitor measures a gas concentration
which is greater than the corresponding alarm limit for the gas.
When this concentration is measured, the Monitor breaks the
connection between pins 1 & 2 or 4 & 5. The monitor will
furthermore activate the internal beeper and write the following
message on the display:
The user can switch off the beeper and the message by pressing
INFO or RESET push-button on the front-panel of the Monitor.
The alarm relays will continue being activated until either (1) all
measured gas concentrations fall below their user-defined alarm
level(s); or (2) the monitoring task is stopped – this automatically
closes the alarm relays.
Alarm Relay 1:
Alarm Relay 1: correspond to High Alarm Limit 1.
Whenever one or more gases exceed their alarm level(s) for high
alarm limit 1, the Monitor breaks the electrical connection
between pins 1 & 2 and this activates the attached alarm system.
Alarm Relay 2:
Alarm Relay 2: correspond to High Alarm Limit 2.
Whenever one or more gases exceed their alarm level(s) for high
alarm limit 2, the Monitor breaks the electrical connection between
pins 4 & 5 and this activates the attached alarm system.
WARNING:
ALARM LIMIT EXCEEDED