Sun Pumps SJT10-120BL - Manual (Page 14)

PUMP ON
float switch open = water tank low = pump ON
PUMP OFF
float switch closed = water tank high = pump OFF
With switch number 1 in the ON position, the controller is configured to accommodate a Normally Closed (N.C.) float switch, pressure
switch or remote toggle switch. In this configuration the controller will operate as follows:
PUMP ON
switch closed = water tank low = pump ON
PUMP OFF
switch open = water tank high = pump OFF
A three minute timeout is default for this feature but is modifiable by switches 3 and 4 to 10 or 30 minutes respectively. This timeout
applies to remote switch and low water cutoff.
Low-Power Shut-Down/Sensorless Low Water Cut-Off Circuit (LPLW)
The Low-Power Shut-Down/ Low Water Cut-Off Circuit (LPLW) turns the pump off any time the controller output power drops below
a functional level. This may be caused by lack of power from the solar panels or from running out of water. This protects the pump in
stall conditions and saves wear on the system when no or very little water is being pumped. This feature must be adjusted for your
specific application.
This feature is always monitoring the output of the motor. If you are not interested in using this feature turn the “LP Adjust” trim pot
fully counter-clockwise. This will give the pump the minimum low power set point possible.
LPLW Adjustment
The Low Water Cut-Off Circuit and the Low Power Shut-Down circuit are adjusted using the same trim pot labeled “LP Adj.” on the
controller. The default is the arrow pointing straight up. This is sufficient for most systems but adjustment will maximize the life and
output of your system. Follow the steps below to adjust this feature.
1. Turn the “LP Adj.” trim pot fully counter clockwise.
2. Turn the “Speed Control” trim pot counter clockwise until the pump is pumping the desired minimum flow. This may be down
to 0 gal/min but is not recommended for proper pump cooling.
3. Turn the “LP Adj.” trim pot clockwise until the pump shuts off.
4. Reset the “Speed Control” trim pot back to the desired position.
Output Power Limit Circuit (Motor Speed Control)
The Output Power Limit Control circuit is used to control the speed of the pump motor and thus the flow rate of the pump. It is primarily
used for low producing wells where the pump output is matched to the production rate of the well. However it can also be used any time
specific flow rates are required.
Output Power Limit Adjustment
The purpose of this procedure is to adjust the output power of the controller and thus reduce the water flow of the pump. If tests have
shown the pump will out produce the well capacity, then the controller “Speed Control” feature can be used to match the flow rate of the
pump to the production of the well.
1. With the system installed and controller properly configured, allow the pump to run at full power at mid-day until the pump starts
surging.
2. Slowly turn the “Speed Control” trim pot located on the face of the controller counter clockwise until the pump stops surging. This
is the point where the pump flow rate equals the well production. This process will probably take a few attempts to “balance” the
system for optimum water production. If maximum water is not a critical issue you may want to reduce the pumps flow rate an
additional 5% to 10% to insure the pump will not run dry.
(NOTE: The trim pot has a15- turn range. It usually takes many complete turns in a counter-clockwise direction before you will
notice any change in water output or output power on the display).