Sun Pumps SIJ 2.2-1300P-135 BL - Manual (Page 14)

Sensor Low Water Cut-off Circuit
The sensor type low water cutoff circuit is designed as a safety feature to protect your pump from running dry or
your tank from over flowing. This feature is designed for use in the submersible SCS systems with the ground wire
installed. For use with the SCB, SCP or SIJ systems contact SunPumps for assistance. The “LW” terminal of the
controller should be attached to a low water sensor electrode which is mounted in your tank or well. The system
can be used to detect low water or to detect high water depending on the position of switch 2 on the dip switch.
When dip switch 2 is in the off position, the low water cutoff circuit expects not to touch water. If water comes
into contact with it, and completes the circuit to ground, the pump will shut off until the water is removed and the
delay timer times out. 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 for low water cutoff only.
Remote Switch
The Remote Switch interface can serve as an automatic system shutdown when used with a water storage tank
mounted float switch, a pressure switch or it can also serve as a manual system shutdown with a remote system
ON/OFF toggle switch. The remote logic circuit allows the use of standard “Pump-Up or Pump Down” float
switches. Please refer to the following operation scenarios for configuration options.
With switch number 1 in the OFF position, the controller is configured to accommodate a Normally Open (N.O.)
float switch or remote toggle switch. In this configuration the controller will operate as follows:
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.