ATI
Q46H/65 Residual Chlorine Dioxide System
Part 6
– Configuration
44
O&M Manual
Rev-J (11/18)
A Delay
This function places an additional amount of time delay on the trip point
for relay A. This delay is in addition to the main delay setting for the
controller. The entry value is limited to a value between 0 and 999
seconds. Press ENTER to initiate user entry mode, and the value will
flash. Use arrow keys to modify value; range is 0 to 999 seconds. Press
ENTER to store the new value.
A Phasing
This function establishes the direction of the relay trip. When phase is
HI, the relay operates in a direct mode. Therefore, the relay energizes
and the LCD indicator illuminates when the ClO
2
value
exceeds
the
setpoint. When the phase is LO, the relay energizes and the LCD
indicator illuminates when the ClO
2
level drops
below
the setpoint. The
failsafe setting does have an impact on this logic. The description here
assumes the failsafe setting is OFF. Press ENTER to initiate user entry
mode, and the entire value will flash. Use the UP arrow key to modify
the desired value; selections include
HI
for direct operation or
LO
for
reverse operation. Press ENTER to store the new value.
See Figure 25 below for a visual description of a typical control relay
application.
If Relay A Mode is set to Alarm Mode,
AL
, then the following settings will
appear in the Config Menu list automatically. In this mode, two setpoints
can be selected on the same relay, to create an alarm band. Phase HI
selection causes the relay to energize outside of the band, and Phase
LO causes the relay to energize inside of the band. This feature enables
one relay to be used as a control relay while the other is used as a HI-LO
Alarm relay at the same time. Setpoint A-LO must be set lower than
Setpoint A-HI. When AL mode is first selected, Setpoint A-LO is
defaulted to 0.
Setpoint: 1.000 ppm
Hyst: 0.050
Delay: 000
Failsafe: OFF
When value rises to
≥
1.000 ppm, relay
closes.
When value falls to
≤
0.950 ppm, relay
opens.
When value rises to
≥
1.050 ppm,
relay
opens.
When value falls to
≤
1.000 ppm, relay
closes.
Settings:
}
1.000 ppm
0.950 ppm
PHASE: HI
ON
HYSTERESIS
OR
“DEAD BAND”
X
OFF
}
1.050 ppm
1.000 ppm
PHASE: LO
OFF
HYSTERESIS
OR
“DEAD BAND”
X
ON
Setpnt A-HI
Hyst A-HI
Delay A-HI
Setpnt A-LO
Hyst A-LO
Delay A-LO
Figure 25 - Control Relay Example
