20
MGT 2” 60M–600M NXT2 SYSTEM 14 DEMAND
OPERATION
BATCH SIZE CALCULATION
Batch size is the term used for the amount of water being softened by the water softener between regenerations. The
NXT2 controller calculates this value automatically based on the values in the program. This is a simple calculation
provided two pieces of information are known:
Capacity of the water softener in grains (gr.)
(i.e. MGT-300 has 300,000 grains capacity per tank).
Hardness of the raw water being treated by the water softener.
BATCH SIZE EQUATION:
Grain Capacity of Softener
Batch Size =
Hardnessof Water (grains per gallon)
SAMPLE CALCULATION
Assume:
Unit is a model MGT-300 softener
The hardness of the water was measured to be 20 grains per gallon
Using our equation take 300,000 ÷ 20 = 15,000 gallons.
10% Safety factor - reserve capacity = 1,500 gallons.
15,000 gallons – 1,500 gallons = 13,500 gallons (batch size)
For immediate regeneration type meter control the meter setting would be at 15,000 gallons. Commonly this value is
adjusted to 90 percent of the actual value (in this example 13,500 gallons) to assure not over-running the softener.
NOTE:
For meter delayed options, the batch size is determined as in our example, except an additional amount of gallons
must be accounted for and deducted from the total to allow soft water to be available until the softener regenerates
at the selected delay time of day or night. This compensation is necessary since the meter will indicate regeneration
required time prior to the set delay time. This can be accomplished on the NXT2 timer by increasing the safety factor
in the
Master Programming
mode.
