ATI
Model A15/82 Fluoride Monitor with Auto-Calibration
27
O&M Manual
Rev-G (6/10)
CONTROL & ALARM OUTPUTS
The Fluoride Monitor is equipped with four relay outputs. Two of these outputs are designated control
relays, a third is used for alarm functions, and the fourth is used to activate a cleaning cycle. The cleaning cycle
function is not implemented in this design as it is not needed for drinking water measurements. The two control
relays are both available only if the Auto Cal feature is disabled. Normally, only relay A is available as a control
relay. Relay B is used to activate the automatic calibration cycle. Relay output wiring is made at the rear of the
monitor as shown in the diagram on page 14.
CONTROL RELAYS
The relays designated control relays may be used for either alarm functions or control functions. Each of
the two relays is SPDT with a 220 VAC 5A resistive contact rating. Each control relay can be programmed as
either a high or a low alarm, and the hysteresis and time delay can also be set.
To program control relays, proceed as follows:
1.
Press the MODE key until SA appears on the left side of the display. The full display will indicate “SA
X.XXppm
o
LO” This refers to setpoint A and indicates the current setting for control relay A. X.XX is
the current setpoint,
o
(or
n
) indicates the current status of the relay, and LO(or HI) indicates a low or
high alarm function.
2.
Press the CAL key once and the display will read “CAL SA S: X.XX”. The value of X.XX is the setpoint
for that relay. Use the UP and DOWN keys to adjust the value to the desired setpoint. Then press the
ENTER key.
3.
The display will now read “CAL SA I: 0.00”. I is the setpoint hysteresis or deadband for that relay. Use
the UP and DOWN keys to adjust the deadband to the desired value. A value of at least 0.05 is
recommended to avoid relay cycling at the actuation point. When the value is set, press the ENTER
key.
4.
The display will now read “CAL SA D: 0.0s”. D is the delay time for relay actuation. Use the UP and
DOWN keys to select the desired delay time in seconds. The maximum delay time is 99.9 seconds.
When the selection is made, press the ENTER key.
5.
The display will return to the original “SA X.XXppm
o
LO”. Press the MODE key to access the “SB
X.XXppm
o
LO” display.
6.
The steps outlined in 1-4 above should be repeated for SB to program operation of relay B.
