GE Autotrol Performa ProSoft 960 Series - Manual (Page 11)

11
Automatic Regeneration
There are two ways to have the control automatically start
a regeneration: calendar override or having the control
monitor the water usage.
Calendar Override
This feature is set in Parameter P14. It can be set for one to
30 days. If it is set to zero, this feature is disabled. When
this feature is active, the control keeps track of the number
of days since the last regeneration and when that number
equals the value set in P14, a regeneration is automatically
started at the Time of Regeneration set in P2.
Control Monitors the Water Usage
The control compares the water usage to the calculated
volume capacity of the system. The control uses the
Capacity Parameter P5 divided by the Hardness
Parameter P3 to calculate the volume capacity of the
system. It also uses a reserve value to determine if a
regeneration is necessary. If the water usage since the last
regeneration is greater than the system capacity minus
the reserve, a regeneration is needed.
Note: If the water usage exceeds 150% of the system
capacity between regenerations, the control will
automatically call for a second regeneration the next day
even if no water is used. This feature is included to make
sure that an exhausted resin bed is completely recharged.
Reserve Options
There are two types of reserve options for this control:
fixed reserve and historical water usage pattern. They are
selected with Parameter P15.
Fixed Reserve
When the fixed reserve is selected, the control multiplies
the maximum system capacity by the percent value set in
Parameter P16 and uses the result as a reserve.
Water Usage Pattern
The other reserve option allows the control to adjust the
reserve based upon the historical water usage pattern of
the system. The control keeps track of the water usage for
each day of the week and uses that day’s average usage
multiplied by 1.2 as the reserve for that day. Every day at
the Time of Regeneration, the control recalculates the
day’s average water usage. If less than 10% of a day’s
average water usage is used, the control will not change
the day’s average. If more than twice the day’s average is
used, the control uses the actual usage in the reserve
calculation.
Since a new installation has no history of water usage, the
control multiplies the percent of capacity value set in
Parameter P16 by the total system capacity to determine
starting average for each day of the week. The factory set
default value for P16 is 30 which means that 30% of the
total system capacity is used for the starting average for
each day.
Program Parameter P15 is also used to select whether the
control waits until the Time of Regeneration set in
Parameter P2 to start a regeneration, or if the control
should begin a regeneration immediately when the
capacity remaining is less than the reserve.