16
SXT Controller Operation
Meter Immediate Control
A Meter Immediate control measures water usage and regener-
ates the system as soon as the calculated system capacity is
depleted. The control calculates the system capacity by divid-
ing the unit capacity (typically expressed in grains/unit volume)
by the feedwater hardness and subtracting the reserve. Meter
Immediate systems generally do not use a reserve volume.
However, in twin tank systems with soft-water regeneration, the
reserve capacity should be set to the volume of water used
during regeneration to prevent hard water break-through. A
Meter Immediate control will also start a regeneration cycle at
the programmed regeneration time if a number of days equal to
the regeneration day override pass before water usage depletes
the calculated system capacity.
Meter Delayed Control
A Meter Delayed Control measures water usage and regener-
ates the system at the programmed regeneration time after the
calculated system capacity is depleted. As with Meter Immediate
systems, the control calculates the system capacity by dividing
the unit capacity by the feedwater hardness and subtracting
the reserve. The reserve should be set to insure that the system
delivers treated water between the time the system capacity
is depleted and the actual regeneration time. A Meter Delayed
control will also start a regeneration cycle at the programmed
regeneration time if a number of days equal to the regeneration
day override pass before water usage depletes the calculated
system capacity.
Time Clock Delayed Control
A Time Clock Delayed Control regenerates the system on a
timed interval. The control will initiate a regeneration cycle at the
programmed regeneration time when the number of days since
the last regeneration equals the regeneration day override value.
Day of the Week Control
This control regenerates the system on a weekly schedule. The
schedule is defined in Master Programming by setting each day
to either “off” or “on.” The control will initiates a regeneration
cycle on days that have been set to “on” at the specified
regeneration time.
Control Operation During Regeneration
During regeneration, the control displays a special regeneration
display. In this display, the control shows the current regeneration
step number the valve is advancing to, or has reached, and the
time remaining in that step. The step number that displays flash-
es until the valve completes driving to this regeneration step posi-
tion. Once all regeneration steps are complete the valve returns
to service and resumes normal operation.
Pressing the Extra Cycle button during a regeneration cycle
immediately advances the valve to the next cycle step position
and resumes normal step timing.
Control Operation During Programming
The control only enters the Program Mode with the valve in ser-
vice. While in the Program Mode, the control continues to oper-
ate normally monitoring water usage and keeping all displays up
to date. Control programming is stored in memory permanently,
eliminating the need for battery backup power.
Manually Initiating a Regeneration
To occur that day at the next scheduled regeneration time:
1. Press the Extra Cycle button. The service icon will flash to
indicate that a regeneration is queued.
2. To cancel a queued regeneration, press the Extra Cycle button.
To occur immediately:
1. When controller is in service, press the Extra Cycle button for
5 seconds on the main screen.
2. The controller advances to Regeneration Cycle Step #1
(Backwash), and begins programmed time count down.
3. Press the Extra Cycle button once to advance valve to
Regeneration Cycle Step #2 (Brine Draw/Rinse).
4. Press the Extra Cycle button once to advance valve to
Regeneration Cycle Step #3 (Rapid rinse).
5. Press the Extra Cycle button once to advance valve to
Regeneration Cycle Step #4 (Brine Refill).
6. Press the Extra Cycle button once more to advance the valve
back to in service.
NOTE: If the unit is a filter or upflow, the cycle step order
may change.
NOTE: If regeneration occurs for any reason prior to the
delayed regeneration time, the manual regeneration
request shall be cleared.
Control Operation During A Power Failure
The SXT includes integral power backup. In the event of power
failure, the control shifts into a power-saving mode. The control
stops monitoring water usage, and the display and motor shut
down, but it continues to keep track of the time and day for a
minimum of 48 hours.
The system configuration settings are stored in a non-volatile
memory and are stored indefinitely with or without line power.
The Time of Day flashes when there has been a power failure.
Press any button to stop the Time of Day from flashing.
If power fails while the unit is in regeneration, the control will save
the current valve position before it shuts down. When power is
restored, the control will resume the regeneration cycle from the
point where power failed. Note that if power fails during a regen-
eration cycle, the valve will remain in it’s current position until
power is restored. The valve system should include all required
safety components to prevent overflows resulting from a power
failure during regeneration.
The control will not start a new regeneration cycle without line
power. If the valve misses a scheduled regeneration due to
a power failure, it will queue a regeneration. Once power is
restored, the control will initiate a regeneration cycle the next time
that the Time of Day equals the programmed regeneration time.
Typically, this means that the valve will regenerate one day after it
was originally scheduled. If the treated water output is important
and power interruptions are expected, the system should be
setup with a sufficient reserve capacity to compensate for
regeneration delays.
