18
Table I. Range and factory alarm level settings.
Control Module
Range
Low Alarm
Level
Hi Alarm
Level
Hi-Hi Alarm
Level
Hydrogen Sulfide (H2S)
100 ppm
10 ppm (NL)
15 ppm (NL)
20 ppm (NL)
Combustible (LEL)
100 %
10 % (NL)
20 % (NL)
30% (NL)
Oxygen (O2)
25 %
17 % (NL)
23 %(NL)
24% (NL)
Sulfur Dioxide (SO2)
50 ppm
5 ppm (NL)
15 ppm (NL)
20 ppm (NL)
Carbon Monoxide (CO)
100 ppm
10 ppm (NL)
20 ppm (NL)
50 ppm (NL)
Nitrogen Dioxide (NO2)
20 ppm
5 ppm (NL)
15 ppm (NL)
20 ppm (NL)
Note that for Oxygen Low Alarm is activated on the depleting oxygen level. That is
Low alarm relay is activated when the oxygen concentration falls below the
programmed low alarm level.