Fixed
The SubDrive Solar controller can be set to a fixed "Off Time" rule via the COMM Board user
interface. It is factory preset to a fixed time of 5 minutes. In this mode, the controller will wait 30
seconds to 5 minutes, determined by duration of the previous run time, before restarting the motor.
For example, the first time the fault occurs, the controller will wait 30 seconds before attempting
to restart the pump. If the system would then run for 1 minute and an underload fault recurs, the
controller will wait 4 minutes before attempting to restart the pump. This schedule allows for the
minimum off-time possible based on the recovery time of the well. The fixed "Off Time" can be set
from 5 to 80 minutes in 5 minute increments. NOTE: The fixed "Off Time" will only take effect if
Parameter 3 is set to 1 = Fixed. (Figure 3)
Flow Switch
A flow switch comes with the SubDrive Solar package to detect low flow or no flow conditions and
prevent damage to the pump, motor, and plumbing. At times of limited sunlight, a point will be
reached where there is not enough solar power available to provide adequate flow. The pump will
reach a deadhead condition, meaning the pump is spinning, but no water is moving. Continuous
operation in a deadhead condition may overheat the pump, motor, and subsequently the plumbing,
since no moving water carries away the heat. This flow switch overrides the "RUN" command from
any other control switches.
The flow switch detects adequate flow, permitting continuous operation, or detects zero or low
flow, enabling a "deadhead" operation mode which alternates a run-time interval and a cool-down
interval, to avoid overheating the motor and pump (see pages 17 and 18 for more information on
Flow Switch Operation). After a certain run time duration, if the flow switch does not detect flow it
will present an E4 fault code. The durations of the run-time and cool-down intervals depend on the
power being supplied by the controller: the more power going to the motor, the shorter the on-
time and longer the cool-down. The controller will operate indefinitely in "deadhead mode", until
available power either increases sufficiently to move adequate water or it decreases sufficiently that
the controller is no longer able to spin the motor. The SubDrive Solar controller will not operate with
the flow switch bypassed or jumpered. The controller is required to see "no flow" before attempting
to start the motor or a fault will occur.
1
2
3
Run Time (Minutes)
6
5
4
3
2
1
0
0
1
2
3
Run Time (Minutes)
Figure 3: Fixed Reset Model
4
5
6
7
8
11