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PV Array-Direct Application
A PV-direct system uses water storage instead of batteries. This
is the simplest and most reliable system, and is easy to transport.
No electronic controls are required. A solar tracker (optional)
will help to maintain optimum flow through the entire solar day.
Storage of 3-7 days' water demand is recommended. PV array direct
is optimum for circulation of solar-heated water.
Performance Chart
for PV Array Direct Applications
Battery Application
A battery system is best where there is need for constant
pressure or pressure on demand, or where a tank is not feasible,
or where a battery system is required for other power applications.
Batteries can be charged by any power source.
Performance
Chart for Battery Applications
Reading the Charts
Select the appropriate chart of "PV Array-Direct Applications"
or "Battery Applications". Total Dynamic Head = Vertical distance
from surface of the water source to the discharge or top of storage
tank + pipe friction losses. Use solid line grid for English units.
Use broken line grid for metric units. Locate the coordinates for
the required head and flow. Find the pump curve that is nearest
to that point. If there is more than one curve to chose from, compare
the power requirements. For PV-Direct systems, array sizing (watts)
is critical. DO NOT undersize the array.
Suction Capacity
Suction limit is 10 vertical feet (3 m) at sea level-subtract
1 foot for every 1000 ft. elevation (1 m per km). For best reliability,
place the pump low and close to the water source to minimize or
eliminate suction.
Pump Placement
Place the pump close to the water source to minimize
suction lift. This will minimize the possibility of cavitation which
causes excessive wear and loss of performance. Horizontal position:
Place outlet at the top. It can be rotated to face horizontally
or vertically upward. Vertical position: Place motor on top. Pump
must be sheltered from rain and direct sunlight.
Wire and Pipe Requirements
Intake pipe: Pipe should be as direct and short as possible.
Avoid any high point that can trap an air pocket. Refer to a pipe
sizing chart (included with the pump instructions). Pipe may need
to be larger than the pump ports. Undersized pipe will greatly decrease
pump performance. Refer to a low voltage wire sizing chart. Size
the wire for less than 3% voltage drop. Undersized wire will greatly
decrease pump performance.
Overcurrent Protection
Fuse or circuit breaker is required. Ampere rating =
amps at the pump + 15-25% Minimum DC voltage rating = volts at the
pump X 2. (Type FRN fuses are rated 125V DC)
Maintenance
No regular maintenance is required. Pump can be repaired
in the field using ordinary tools and skills, without removing the
pipes. Instruction manual shows illustrated repair details. Motor
brushes: Typical brush life peak hours = working voltage X 800 /
3rd digit of model number. EXAMPLE: PV-Direct curve #60 is Model
7526 working at 30V. Typical brush life = 30 X 800 / 2 = 12,000
peak hours. This represents about 5-8 years of service. Shaft seal
has a very long life under normal conditions. Purchase spare seals
if water is loaded with abrasive silt or if pump can possibly run
dry.
Materials
Pump body: cast iron, ASTM A48-76 Impeller: glass filled
polycarbonate Seal: carbon/ceramic, industry standard Temperature
limit: 140°F (60°C)
High Temperature Option
Temperature limit: 212°F (100°C) Impeller: brass Brass
impeller reduces flow by approximately 15% (power is same) Order
a standard pump + Item #38275. It will be indicated on the pump
as "HT" added to model number.
Accessories
Foot Valve (required if pump is placed higher than water
source) Float switches: please inquire
Spare Parts
Seal & Gasket Kit: specify pump number, and if high
temperature Motor Brush Kits: specify model number
Warranty
Two years against defects in materials and workmanship.
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