Sun Pumps MTR BLM-SB-103S-120Y - Manual (Page 12)

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 one minute minimum timeout is default for this feature but is modifiable by switches 3 and 4 to 10 or 30
minutes respectively. At certain times the controller may be off for up to 14 minutes depending on various
factors in the controller program. 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 Adj” 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.