20
• ALWAYS OFF if pH > setpoint;
Using a similar format, the second relay may be set up
according to the diagram below.
ALARM RELAY
The alarm relay functions in the following manner:
FS•O = NC (Normally Closed)
De-energized Relay
COM
FS•C = NO (Normally Open)
Energized Relay
During alarm condition, the relay is de-energized. When
not in alarm condition, the relay is energized.
Example:
High alarm set at 10 pH
Low alarm set at 4 pH
Note
If the power supply is interrupted, the relay is de-energized
as if in alarm condition to alert the operator.
ON
OFF
Low setpoint mode
0
alarm
Setpoint
14
Setpoint–
Deviation
High setpoint mode
alarm
ON
OFF
0
Se
Deviation
Setpoint
14
