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Dankoff Slowpump 2507-12 12VDC SURFACE PUMP
|Item code||Brand name||Model number|
|DAKSL-2507-12||Dankoff Solar Pumps||Slowpump 2507-12|
SLOWPUMP® SOLAR PUMP
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 560 vertical feet (170m).
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 560 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
- Handles sea water, dissolved
- 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
1300 & 2500 series
1/5 HP * PV Direct or Battery 12VDC, 24VDC, 48VDC, 115VAC
Model Numbers (Add -12 or -24 or -48 to indicate voltage)
|Technical data Dankoff Solar Slowpump|
1400 & 2600 series 1/2 HP * PV Direct or Battery 24VDC, 48VDC, 115VAC
Model Numbers (Add -24 or -48 to indicate voltage)
|Technical data Dankoff Solar Slowpump|
Reading the Performance Charts
- Identify Total Lift for your application = Vertical Distance from surface of the water source to the pipe outlet or top of storage tank, plus any pipe friction loss
- Choose SlowPump model based on desired output (GPM) and/or required solar power (PV Watts) at the Total Lift
- Select the desired pump Voltage from the available options for that model
** Actual performance may vary +/- 10% from specifications - based on PV-Direct voltage of 15, 30, or 60 (the standard Vmp of 12V, 24V, and 48V configurations at STC). For battery-based applications, subtract 20% from Flow and Watts.
** PV Watts column is the recommended power after taking the Watts required at the Pump and upsizing by 25% for de-ration, then rounding to the nearest increment of 5.
- 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 to reduce suction lift.
- These pumps CANNOT tolerate dirt. Water MUST be filtered clear. Failure to use a Dankoff Solar Pumps filter unit, or use of a filtration unit other than Dankoff, will void the warranty on the pump. If water is very dirty, improve the source or consider using Dankoff's dirt-tolerant pump models (SolarForce, SunCentric, or Solaram).
PV-Direct (non-battery) Requirements
- The rated power of the PV array must meet the Watts listed in PV Watts column in chart above.
- 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)
- 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
- Linear Current Boosters (LCB) for PV-Direct (12V/24V: 5Amp, 8Amp, 15Amp, 48V: 10Amp)
- 1300/1400 Series: 1/2 inch female pipe thread
- 2500/2600 Series: 3/4 inch male thread
- 1300/2500 Series: 5.75 x 17.4 inches (14.6 x 44.1 cm), 13 lbs (5.9kg)
- 1400/2600 Series: 6.5 x 18.75 inches (16.51 x 47.63 cm), 25 lbs (1400 series), 29 lbs (2600 series)
- 1 year against defects in materials and workmanship. Failure to use a Dankoff filter unit 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
SolarForce PistonPumps 30xx
Solaram Pumps 8xxx
*formerly 13xx and 25xx
Here are some tips from the altE staff
- Do I really need a pump controller?
- In the most basic sense, no. But for a variety of reasons, including the appropriate controller in your system makes for a better, longer lasting pumping system. A key feature to most pump controllers is what is called a linear current booster, or LCB. LCBs improve the performance of DC pumps by adjusting the voltage and current to increase the output in low light conditions, like mornings and evenings, and on cloudy days. But controllers do more than that. They reduce arcing between the brushes and the motor, significantly extending the life of the pump. Controllers also have terminals for a switch, like a float switch or pressure switch. Some controllers come with manual on/off switches, as well as internal fuses to protect against shorts. Finally, depending on the controller, they have low water probes, hi/low voltage protection, and other features. It is for all of these reasons that a pump controller is highly recommended.
- Can I use a float switch without a pump control box?
- Technically, yes. But because of the usual limitations, it isn't recommended. If one were to connect a float switch inline with the electrical circuit for the system, the wires in that switch would be carrying the current for the system. For systems with longer wire runs, comparatively larger wire is needed to reduce power losses. But the wire for a float switch isn't sized to carry large current loads. If one were to connect a float switch inline with the electrical circuit of a long cable run, the wires from the float switch would be insufficient handle the current and would result in significant power loss at best and melted cable insulation (and possibly a fire hazard) at worst. The contacts on the switch itself - what opens and closes the electrical circuit - would wear out sooner. Pump controllers typically have terminals for an electric switch (usually a float, pressure or dry run switch) that is a relay for the switch. As such, it makes it possible for the switch to function without carrying all the current in the system. This is why the wires for the switches are so small.
- What if I just don't want, or can't, use a pump controller, but I want to use a float switch?
- In this case you would have two options. First, if you can reduce the length of the float switch cable to a couple of feet, then probably the loss in the line wouldn't be too significant. But this will vary from one system to the next, and consulting a sales tech is recommended. The second option you have is to use a high current float switch. We have one that is designed for up to 25 amps. However, it contains mercury and is not recommended for drinking water.
- If I want to make the wire longer on my float switch, can I do that?
- Yes, if you are using a control box. The length will vary from one switch to the next, but for many switches you can extend the length up to 1000 feet and for some up to 2000 feet. On the other hand, lengthy runs usually means digging a trench to protect the cable from critters and exposure to weather. To avoid that challenge, one alternative is to use a combination pressure switch and float valve. When connected to a pump controller, a pressure switch will turn a pump on and off based on the pressure it senses in the water line. When the pressure rises, the switch turns the pump off, and when the pressure drops, the switch turns the pump on. A float valve (aka ball valve) is used when one is filling a water tank and will open and close the water line based on the water level of the tank.
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