Information taken Directly from the Dankoff site
DANKOFF
SLOWPUMP® SOLAR PUMP
MODELS: 1300,1400,2500,2600
Use Solar-Electric Power to provide 200-2,600 Gallons per Day (750-10,000 ltrs.) from shallow water sources. Slowpump can push water as high as 450 vertical feet (137m).
Solar Slowpump was the world's first commercially available low power solar pump. It was developed by Windy Dankoff in 1983, in response to those who said "that's impossible." Thousands of Slowpumps have been installed worldwide by ranchers, homeowners, missionaries, health workers, government agencies, etc. Some of our oldest Slowpumps are still in daily service.
Slowpump is not submersible, but can draw water from shallow wells, springs, cisterns, tanks, ponds, rivers, and streams, and push it as high as 450 vertical feet and through miles (kilometers) of pipeline. Slow pumping minimizes the size and cost of the solar array, wire and piping.
Slowpump is less expensive than sub-mersible DC pumps, and made in a much wider range of sizes. Wearing parts typically last 5 to 10 years. Overall life expectancy is 15-20 years.
"The Slowpump #2507-24V is supplying water for a work camp on the outer island of Onotoa. It's supplying water for 60 people. The well is one half mile 800m away from the camp." -- B.C., Ministry of Works and Energy, Kiribati, South Pacific
"I have been very happy with the 1308 Solar Slowpump!...We are using it in a 5 meter deep hand dug well in a valley, and pumping 200 meters distant and 50 meters vertically." ---
Dr. D.L., World Missions, Cameroon, W. Africa
"These pumps work great.... Even during low light levels when the motor is turning slowly, a small amount of water can be pumped.... The manual is easy to read. Windy's troubleshooting section is excellent....Not only have these pumps stood the test of time, but small changes have made them even better." --- B. Schultze -product review in Home Power Magazine #42
CONSTRUCTION & FEATURES
Rotary vane mechanism (positive displacement) made of forged brass, carbon-graphite and stainless steel
NSF® approved for drinking water
Handles sea water, dissolved minerals
Survives most freezes
Permanent magnet, DC motor
AC models use a low-surge PM motor that greatly reduces starting surges, inverter and wire size requirements
Installation and Service Manual is highly detailed and illustrated
Reading the Performance Chart
Total Lift = Vertical Distance from surface of the water source to the pipe outlet or top of storage tank, plus any pipe friction loss
Suction Capacity
20 vertical feet (6 m) at sea level -- subtract 1 ft. for every 1000 ft. altitude (1 m for every 1000 m). Pump should be mounted as close to the water source as possible.
Filtration Requirement
This pump CANNOT tolerate dirt. Water MUST be filtered to <10 microns using a disposable cartridge filter. If water is very dirty, prefilter it, improve the source, or consider a different pump.
PV-Direct (non-battery) Requirements
The rated power of the PV array must exceed the pump watts by 20% or more.
A Linear Current Booster (controller) is required to function in varying light conditions (12V/24V: 5Amp, 8Amp, 15Amp, 48V: 10Amp)
Solar Tracker (optional) to increase daily yield (40-55% in summer)
Accessories
Intake Strainer/Foot Valve with fine monel metal screen, stops course debris
Inline 10 micron Filter (10-inch) uses standard drinking water cartridges
Intake Filter/Foot Valve (30-inch) replaces Intake Strainer and Inline Filter (10 micron) with a single unit, best for lowering into a shallow well
Spare Filter Cartridges (5 or 10 micron spun fiber)
Dry Run Switch prevents battery drain and pump damage if water source
runs dry
Linear Current Boosters (LCB) for PV-Direct (12V/24V: 5Amp, 8Amp, 15Amp, 48V: 10Amp)
Fittings
1300/1400 Series: 1/2 inch female pipe thread
2500/2600 Series: 3/4 inch male thread
Dimensions (1300/2500-Series)
5.7 x 15.5 inches (14 x 39 cm)
Weight 16 lbs (7 kg)
Warranty
1 year against defects in materials and workmanship. Use of pump without 10 micron or less filter will void warranty.
Surface Pumps Comparison
Surface pumps for lifting and/or pressurizing water / 1 PSI = 2.307 ft. of
Surface Pumps Min Lift (ft) Max Lift (ft) Min Lift (PSI) Max Lift (PSI) Min GPM Max GPM Pump Type Dirt Tolerant Filtration Required Dry-run Tolerant
Solar Slowpumps 15xxx*
0 440 0 191 0.4 4 rotary vane N 10 mic N
Solar Slowpumps 14xx and 26xx
160 440 69 191 1 4 rotary vane N 10 mic N
Flowlight Booster Pumps 16xxx**
69 150 30 65 3 4 rotary vane N 10 mic N
SunCentric Pumps 7xxx
0 90 0 39 5 70 centrifugal high N Y
SolarForce PistonPumps 30xx
0 220 0 95 4 9 piston medium N Y
Solaram Pumps 8xxx
0 960 0 416 3 9 diaphragm medium N Y