Schoener 50
1771 ED Wieringerwerf
The Netherlands
Tel/fax 0031-227-604128
Homepage: http://www.flowman.nl
E-mail:pumps@flowman.nl
FLOWMAN
ADVANCED PUMP TECHNOLOGIES
Edition 04 : 01 January, 2002
SOLAR SPRING SOLAR SUBMERSIBLE PUMPS
ACKNOWLEDGMENT
This material was written by Windy Dankoff and is re-produced by kind permission of Dankoff Solar Products, Santa Fe (NM) USA, and may be
freely copied without alteration by third parties as required on condition that both author and source are duly cited.
Glossary of Solar Water Pumping Terms
Basic Electricity
AC-Alternating Current
The standard form of electrical current supplied by the utility grid and by most fuel-powered generators. The polarity (and therefore the direction of current) alternates. Standard voltages for small water pumps are 115V and 230V. Standards vary in different countries. (See Inverter).
DC-Direct Current
The type of power produced by photovoltaic panels and by storage batteries. The current flows in one direction and polarity is fixed, defined as positive (+) and negative (-). Nominal system voltage may be anywhere from 12 to 180V. (See voltage, nominal).
Current
The rate at which electricity flows through a circuit, to transfer energy. Measured in Amperes, commonly called Amps. Analogy: Flow Rate in a water pipe.
Efficiency
The percentage of power that gets converted to useful work. Example: An electric pump that is 60% efficient converts 60% of the input energy into work - pumping water. The remaining 40% becomes waste heat. The efficiency of a pump is equal to (vertical lift in feet x gallons per minute x 18.8) divided by the number of watts.
Energy
The product of power and time, measured in Watt-Hours. 1000 Watt-Hours = 1 Kilowatt-Hour (abbreviation: KWH). Variation: the product of current and time is Ampere-Hours, also called Amp-Hours (abbreviation: AH). 1000 watt consumed for 1 hour = 1 KWH. See Power.
Converter
An electronic device for DC power that steps up voltage and steps down current proportionally (or vice-versa). Electrical analogy applied to AC: See Transformer. Mechanical analogy: gears or belt drive.
Inverter
An electronic device that converts low voltage DC to high voltage AC power. In solar-electric systems, an inverter may take the 12, 24, or 48 volts DC and convert it to 115 or 230 volts AC, conventional household power.
Multimeter
A test instrument capable of measuring voltage, current, and resistance.
Power
The rate at which work is done. It is the product of Voltage times Current, measured in Watts. 1000 Watts = 1 Kilowatt. An electric motor requires approximately 1 Kilowatt per Horsepower (after typical efficiency losses). 1 Kilowatt for 1 Hour = 1 Kilowatt-Hour (KWH).
Transformer
An electrical device that steps up voltage and steps down current proportionally (or vice-versa). Transformers work with AC only. For DC, see Converter. Mechanical analogy: gears or belt drive.
Utility Grid
Commercial electric power distribution system. Synonym: Mains.
Voltage
The measurement of electrical potential. Analogy: Pressure in a water pipe.
Voltage Drop
Loss of voltage (electrical pressure) caused by the resistance in wire and electrical devices. Proper wire sizing will minimize voltage drop, particularly over long distances. Voltage drop is determined by 4 factors: wire size, current (amps), voltage, and length of wire. It is determined by a consulting wire sizing chart or formula available in various reference texts. It is expressed as a percentage. Water analogy: Friction Loss in pipe.
Voltage, nominal
A way of naming a range of voltage to a standard. Example: A "12 Volt Nominal" system may operate in the range of 11 to 15 Volts. We call it "12 Volts" for simplicity.
Solar Electricity
Photovoltaic
The phenomenon of converting light to electric power. Photo = light, Volt = electricity. Abbreviation: PV.
PV
The common abbreviation for photovoltaic.
PV Array
A group of PV (photovoltaic) modules (also called panels) arranged to produce the voltage and power desired.
PV Array-Direct
The use of electric power directly from a photovoltaic array, without storage batteries to store or stabilize it. Most solar water pumps work this way, utilizing a tank to store water.
PV Cell
The individual photovoltaic device. The most common PV modules are made with 33 to 36 silicon cells each producing 1/2 volt.
PV Module
An assembly of PV cells framed into a weatherproof unit. Commonly called a "PV panel". See PV Array.
Solar Tracker
A mounting rack for a PV array that automatically tilts to follow the daily path of the sun through the sky. A "tracking array" will produce more energy through the course of the day than a "fixed array" (non-tracking) particularly during the long days of summer.
Voltage, Open Circuit
The voltage of a PV module or array with no load (when it is disconnected). A "12 Volt Nominal" PV module will produce about 20 Volts open circuit. Abbreviation: Voc.
Voltage, Peak Power Point
The voltage at which a photovoltaic module or array transfers the greatest amount of power (watts). A "12 Volt Nominal" PV module will typically have a peak power voltage of around 17 volts. A PV array-direct solar pump will reach this voltage in full sun conditions. In a higher voltage array, it will be a multiple of this voltage. Abbreviation: Vpp.
Pumps & Related Components
Booster Pump
A surface pump used to increase pressure in a water line, or to pull from a storage tank and pressurize a water system. See Surface Pump.
Centrifugal Pump
A pumping mechanism that spins water by means of an "impeller". Water is pushed out by centrifugal force. See also multi-stage.
Check Valve
A valve that allows water to flow one way but not the other.
Diaphragm Pump
A type of pump in which water is drawn in and forced out of one or more chambers by a flexible diaphragm. Check valves let water into and out of each chamber.
Foot Valve
A check valve placed in the water source below a surface pump. It prevents water from flowing back down the pipe and "losing prime". See check valve and priming.
Positive Displacement Pump
A mechanism that seals water in a chamber then forces it out by reducing the volume of the chamber. Examples: piston (including jack), diaphragm, rotary vane. Used for low volume and high lift. Contrast with "centrifugal". Synonyms: volumetric pump, force pump.
Impeller
See Centrifugal Pump
Jet Pump
A surface-mounted centrifugal pump that uses an "ejector" (venturi) device to augment its suction capacity. In a "deep well jet pump", the ejector is down in the well, to assist the pump in overcoming the limitations of suction (some water is diverted back down the well). Jet pumps are NOT energy-efficient.
Multi-Stage Centrifugal
A centrifugal pump with more than one impeller and chamber, stacked in a sequence to produce higher pressure. Conventional AC deep well submersible pumps and higher power solar submersibles work this way.
Priming
The process of hand-filling the suction pipe and intake of a surface pump. Priming is generally necessary when a pump must be located above the water source. A "self-priming" pump is able to draw some air suction in order to prime itself, at least in theory. See "foot valve".
Pulsation Damper
A device that absorbs and releases pulsations in flow produced by a piston or diaphragm pump. Consists of a chamber with air trapped within it.
Pump Jack
A deep well piston pump. The piston and cylinder is submerged in the well water and actuated by a rod inside the drop pipe, powered by a motor at the surface. This is an old-fashioned system still used for extremely deep wells, including solar pumps as deep as 1000 feet.
Sealed Piston Pump
A type of pump in which water is drawn in and forced out of a chamber by a piston mechanism. The pistons have a very short stroke, allowing the use of flexible gaskets to seal water out of the piston mechanism. Check valves let water into and out of the chamber.
Submersible Pump
A motor/pump combination designed to be placed entirely below the water surface.
Surface Pump
A pump that is not submersible. It must be placed no more than about 20 above the surface of the water in the well. See priming. (Exception: see jet pump)
Vane Pump - (Rotary Vane)
A positive displacement mechanism used in low volume high lift surface pumps and booster pumps. Durable and efficient, but requires cleanly filtered water due to its mechanical precision.
Solar Pump Components
DC Motor, Brush-Type
The traditional DC motor, in which small carbon blocks called "brushes" conduct current into the spinning portion of the motor. They are used in DC surface pumps and also in DC submersible diaphragm pumps. Brushes naturally wear down after years of use, and may be easily replaced.
DC Motor, Brushless
High-technology motor used in centrifugal-type DC submersibles. The motor is filled with oil, to keep water out. An electronic system is used to precisely alternate the current, causing the motor to spin.
DC Motor, Permanent Magnet
All DC solar pumps use this type of motor in some form. Being a variable speed motor by nature, reduced voltage (in low sun) produces proportionally reduced speed, and causes no harm to the motor. Contrast: induction motor
Induction Motor (AC)
The type of electric motor used in conventional AC water pumps. It requires a high surge of current to start and a stable voltage supply, making it a challenge to run from a solar power system. See "inverter".
Linear Current Booster
See "pump controller". Note: Although this term has become generic, its abbreviation "LCB" is a trademark of Bobier Electronics
Pump Controller
An electronic device which varies the voltage and current of a PV array to match the needs of an array-direct pump. It allows the pump to start and to run under low sun conditions without stalling out. Electrical analogy: variable transformer. Mechanical analogy: automatic transmission. See "Linear Current Booster".
Water Well Components
Borehole
Synonym for water well, especially outside of North America.
Casing
Plastic or steel tube that is permanently inserted in the well after drilling. Its size is specified according to its inside diameter.
Cable Splice
A joint in electrical cable. A submersible splice must be made using special materials available in kit form.
Drop Pipe
The pipe that carries water from a pump in a well up to the surface.
Perforations
Slits cut into the well casing to allow groundwater to enter. May be located at more than one level, to coincide with water-bearing strata.
Pitless Adapter
A special pipe fitting that fits on a well casing, below ground. It allows the pipe to pass horizontally through the casing so that no pipe is exposed above ground where it could freeze. The pump may be installed and removed without further need to dig around the casing. This is done by using a 1 inch threaded pipe as a handle.
Safety Rope
Plastic rope used to suspend the pump, primarily in case of pipe breakage.
Submersible Cable
Electrical cable designed for in-well submersion. Size (in USA) is specified by American Wire Gauge (AWG), in which a higher number indicates smaller wire. The specification "two-wire plus ground" will indicate three wires (conductors) in the cable. It is connected to a pump by splicing.
Well Seal
Top plate of well casing that provides a sanitary seal and support for the drop pipe and pump. Alternative: See "Pitless Adapter"
Water Well Characteristics
Driller's Log
The written form on which well characteristics are recorded by the well driller. In many states, it is a legal requirement to register all water wells and to send a copy of the log to a state office. This supplies hydrological data and well performance test results to the public and to the well owner.
Drawdown
Lowering of level of water in a well due to pumping.
Recovery Rate
Rate at which groundwater refills the casing after the level is drawn down. This is the term used to specify the production rate of the well.
Static Water Level
Depth to the water surface in a well under static conditions (not being pumped). May be subject to seasonal changes or lowering due to depletion.
Wellhead
Top of the well, at ground level.
Pump System Engineering
Friction Loss
The loss of pressure due to flow of water in pipe. This is determined by 3 factors: pipe size (inside diameter), flow rate, and length of pipe. It is determined by consulting a friction loss chart available in an engineering reference book or from a pipe supplier. It is expressed in PSI or Feet (equivalent additional feet of pumping).
Head
See synonym: "vertical lift".
Suction Lift
Applied to surface pumps: Vertical distance from the surface of water in the source, to a pump located above surface pump located above. This distance is limited by physics to around 20 feet at sea level (subtract 1 ft. per 1000 ft. altitude) and should be minimized for best results.
Submergence
Applied to submersible pumps: Distance beneath the static water level, at which a pump is set. Synonym: immersion level.
Total Dynamic Head
Vertical lift + friction loss in piping (see friction loss).
Vertical Lift
The vertical distance that water is pumped. This determines the pressure that the pump pushes against. Total vertical lift = vertical lift from surface of water source up to the discharge in the tank + (in a pressure system) discharge pressure. Synonym: static head. Note: Horizontal distance does NOT add to the vertical lift, except in terms of pipe friction loss. NOR does the volume (weight) of water contained in pipe or tank. Submergence of the pump does NOT add to the vertical lift in the case of a centrifugal type pump. In the case of a positive displacement pump, it may add to the lift somewhat.
Vertical lift - measurement
Vertical lift is measured from the SURFACE of the water source to the pump outlet OR the water level in the storage tank (whicever is the higher) + friction loss. The load on the pump is NOT affected by the volume of water in the pipe or in the tank.
Water Distribution
Cut-In Pressure and Cut-Out Pressure
See "pressure switch".
Gravity Flow
The use of gravity to produce pressure and water flow. A storage tank is elevated above the point of use, so that water will flow with no further pumping required. A booster pump may be used to increase pressure. 2.3 Verticl Feet = 1 PSI. See pressure.
Head
See "vertical lift" and "total dynamic head". In water distribution, synonym: "vertical drop".
Open Discharge
The filling of a water vessel that is not sealed to hold pressure. Examples: storage (holding) tank, pond, flood irrigation. Contrast: pressure tank.
Pressure
The amount of force applied by water that is either forced by a pump, or by gravity. Measured in pounds per square inch (PSI). PSI = vertical lift (or drop) in Feet/2.31.
Pressure Switch
An electrical switch actuated by the pressure in a pressure tank. When the pressure drops to a low set-point (cut-in) it turns a pump on. At a high point (cut-out) it turns the pump off.
Pressure Tank
A fully enclosed tank with an air space inside. As water is forced in, the air compresses. The stored water may be released after the pump has stopped. Most pressure tanks contain a rubber bladder to capture the air. If so, synonym: captive air tank.
Pressure Tank Precharge
The pressure of compressed air stored in a captive air pressure tank. A reading should be taken with an air pressure gauge (tyre gauge) with water pressure at zero. The air pressure is then adjusted to about 3 PSI lower than the cut-in pressure (see "Pressure Switch"). If precharge is not set properly, the tank will not work to full capacity, and the pump will cycle on and off more frequently.
FOR MORE INFORMATION ON THE SOLAR SPRING PUMPS PLEASE GO TO:
GENERAL FILE FOR THE SOLAR SPRING PUMPS
RETURN TO:
If you cannot find the information you require on these pages, please contact Terry Manning
by e-mail on : pumps@flowman.nl or
telephone or fax him at 0031-227-604128.
E-mail Terry Manning