Sun Pumps SCB-10-150-120 BL - Manual (Page 5)

As the majority of system installations vary greatly, only general comments can be made as to location.
Prior to installing the system, it is suggested to make a system layout plan. During the system layout, take
into consideration any potential shading of the solar electric modules, wire runs, wire size, conduit runs,
trenching, controller accessibility, tank location, pump head etc. Shading even a small portion of the array
can reduce the output of the entire array and thus reduce or completely stop the output of the pump. There
is no substitute for a good plan!
The PCC-series controller can either be mounted indoors or outdoors. Locate all system equipment as
close as possible to each other. For top of pole mount racks, the controller is usually mounted on the north
side (shaded side) of the mounting pole. The controller must be mounted in a vertical position for proper
cooling and to keep the electronics dry. The pole should be located close to the well (bore hole). This
general physical layout is conducive to clean installation both aesthetically and electrically.
3.2 System Design Basics (Read carefully before installation)
1. The pump discharge piping should be sized for efficient pump operation. We suggest using the
Friction Loss Tables to calculate the Total Dynamic Head using different pipe sizes. As a rule of
thumb use 1” for up to 8 GPM, 1 ¼” for up to 25 GPM, 1 ½” for up to 40 GPM and 2” for up to
70 GPM.
2.
For optimum pump performance make sure that the wire is sized properly for the length of run
between the pump and the solar modules. Wire sized too small will cause a decreased output
from the pump. Keep the distance from the solar modules to the pump as short as possible.
Refer to a DC wire loss chart for proper sizing. It is recommended to keep the voltage drop
under 3%.
3. The SCB series booster pumps do not have good suction lift capabilities and it is recommended
to always have a positive suction head if possible. (Water above the inlet of the pump.) If this is
not possible then keep the suction lift to a minimum, no more than three feet.
4. Always use a foot valve on the suction hose with a negative suction lift. Keep the suction hose
in a straight sloping line without any loops where air could be trapped. Keep the suction hose as
short as possible.
5. Always fill the suction hose and the pump with water before you turn the pump on. If the pump
is operated dry, damage to the impellers will occur and dry running is not covered under
warranty.
6. If pumping from a tank or any source that could run low on water, install a low water float
switch to protect the pump from running dry.
7. If a pressure switch is used in the system, choose one with a Low Pressure Cut-Off. If the pump
runs dry the pressure will drop and the low pressure switch will turn the pump off.
8. Never install the controller in direct sunlight. Direct sunlight on the controller may cause over-
heating of the controller.
9. Never lay the controller on the ground or mount the controller in a horizontal position. The
controller should be mounted in a vertical position only. A convenient place to mount the
controller is on the north side (shaded side) of the solar module array.
10. The controller should be grounded to the pump motor housing, the frame of the solar modules
and to an 8-foot ground rod. If the well casing is steel it may be used as the ground rod. Drill
and tap a hole in the casing or weld a bolt to the casing for the ground lug. Use only a copper
lug to attach the ground wire. The cemented support structure pole will not provide an adequate
ground. Do not ground the positive or negative electrical wires. Always use a DC
surge/lightning arrestor on the panel side of the controller. (Midnight Solar MN-SPD surge
arrestor is recommended)
11. Do not ground the array positive or negative electrical wires.