Omega Engineering OS137 manual Alarm Setting

Operation 3

3.4Alarm Setting

The unit provides 0-100% alarm setpoint adjustment. Here is an example of an alarm setting:

•An OS137-3-MA (4/20 mA output), the alarm is to be set at 204°C (400°F) temperature.

•Connect the alarm output as shown in Fig. 2-2.

•Remove the End Cap to get to the Alarm Switch and the Alarm Adjust (Fig. 3-2).

•Set the Slide Switch on the main board to the Alarm position (2).

•Measure the analog output, and adjust the Alarm Potentiometer until the output reads 10.4 mA which is 40% (204°C, 400°F) of the temperature range -18 to 538°C, (0 to 1000°F)

[10.4mA = 40 x (20-4) + 4] 100

•Set the Alarm Slide Switch back to the Real Time position (1).

•If the temperature reading is below the alarm setpoint, the Alarm Output stays low, otherwise it goes high (Alarm Condition).

•The Alarm Output can drive an external mechanical relay.

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