User Manual

ENMET Corporation ISA 200 RAL (O)

4.0 Operation4.0 Operation

4.1 Normal Operation Condition

With the ISA-200 RAL(O) installed as described in section 3, and in clean air, the POWER green LED is on, the

display is lit, the flowmeter reads approximately 2 SCFH, and the information on the display is as shown in Figure 4

Display, for the sensor(s) installed in the ISA-200 RAL(O). The red alarm and fault LEDs are not lit.

Example of display with O (Oxygen) option installed

Figure 4: ISA-200 RAL(O) Operational Display

4.2 Alarm Set Points

There is one alarm set point for CO, and two for oxygen. The factory settings of these alarm set points are as follows:

Table 4: Factory Alarm Set Points

Gas Set Point

Carbon Monoxide 10 ppm

Oxygen Deficiency 19.5 % by volume

Oxygen Abundance 23.5 % by volume

These alarm set points can be changed within limits; see the maintenance portion of this manual for the procedure.

If the CO concentration increases above that of the alarm set point, the associated red LED is lit, the associated relay

changes state, and the audio alarm is activated.

If the oxygen content of the sample air decreases below the deficiency alarm set point, the associated red LED is lit,

the associated relay chances state, and the audio alarm is activated.

If the oxygen content of the sample air exceeds that of the abundance alarm set point, the associated red LED is lit, the

audio alarm is activated, and both the oxygen alarm relay and the oxygen high alarm relay change state. There is one

alarm LED for both the deficiency and abundance alarms.

4.3 Alarm Latching

An instrument is shipped with the alarms in the non-latching mode. The alarms may be independently configured in

the non-latching mode by use of the maintenance menu.

§ IN THE LATCHING MODE: at the cessation of the condition which causes an alarm, the alarm indications do not

cease, and the alarm relay contacts do not revert to the non-alarm state, until the ALARM ACKN/AUDIO

DEFEAT switch is pressed. An alarm can also be acknowledged by pressing the switch during the alarm

condition; then at the cessation of the alarm condition, alarm indications cease and alarm relays revert to the non-

alarm state. After an alarm is acknowledged, alarms in the latching configuration are re-armed to latch at the next

alarm condition.

§ IN THE NON-LATCHING MODE: at the cessation of the condition which causes an alarm, the alarm indications

automatically cease, and the alarm relay contacts revert to the non-alarm state.

000 PPM 20.9%

FLOW:y

PPM