ENMET ISA-44-RALE-OD - Manual (Page 19)

ISA-44RALE-OD/ISA-44RAHE-OD/ISA-44E-OD ENMET Corporation
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4.3 Operating Alarm Conditions
Any spontaneous alarm on any channel, not triggered by initial warm-up or rough test, should be considered a potentially
serious gas alarm situation. Do not ignore any alarm condition. Take action.
Precautions
♦
Do not blow dense clouds of cigarette smoke on a sensor to trigger an alarm.
♦
Do not squirt pure gases or liquid hydrocarbons, such as butane, propane, gasoline, etc., directly on the sensor element.
♦
Do not use strong cleaning agents, waxes, paints, lacquers, etc., near a sensor. Most of these contain flammable
hydrocarbons that may trigger the alarm.
Normal operating condition:
Condition Signals Indication
Non-alarm operation Green LED's for both gas and oxygen
channels are on. Unit is operating. Gas content of air is
below the gas channel low alarm point.
Oxygen content is above the oxygen
channel alarm point.
This is the normal operating condition for the ISA-44E-OD instrument. If on the ISA-44RALE-OD air is bubbling
through the sample head assembly humidifier, the signals listed above give positive indication that the unit is operating
and is not in alarm.
Alarm State:
Condition Signals Indication
Power Interruption No LED's are on. Power to the instrument has been
interrupted.
When all the LED's on the display plate are off, the power has been interrupted. The relay contacts are in alarm state, but
will not engage auxiliary equipment unless such equipment is connected to a separate power source which is still
operating.
Oxygen Alarm State:
Condition Signals Indication
Oxygen Deficiency Alarm Oxygen channel green LED is off, red
LED is on, meter shows 19.5% oxygen
by volume or less.
Oxygen channel relay contacts in alarm
state. Horn (optional) is on.
Less than 19.5% oxygen by volume in
the monitored, air.
An oxygen alarm is indicated by the red LED of the oxygen channel on the display plate. This indicates that there is less
than the minimum oxygen requirement of grade D air (19.5% oxygen by volume) in the monitored air. If the oxygen
content of the air subsequently rises above the 19.5% by volume alarm point. The red LED will turn off, the green LED
will come on, and the relays will automatically reset. If the ISA-44RALE-OD/ISA-44E-OD is equipped with a factory
installed audio alarm (horn), it will activate during the oxygen alarm.
W ARNING :
If the Oxygen Deficiency Alarm signals are on, and the oxygen meter is at bottom scale, it is possible that the
oxygen concentration of the compressor air is low enough to cause serious injury or even quick death. Take
action.
N OTE : Sometimes an oxygen alarm indicates a depleted oxygen cell, an "open" I.S. barrier, or a bad connection. See
sections 7.1 and 7.3 for explanation.