Lorentz PS200 Installation Operation & Maintenance page 46

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.
Helical Rotor Pump - A pump with a helix-shaped
rotor that fits closely into a rubber stator that has a helical
groove. It forms sealed cavities that trap water. As the rotor
turns, the cavities move toward the outlet. See positive
displacement pump. Synonyms: progressive cavity pump,
screw pump.
Impeller - The device that spins inside of a centrifugal
pump, in order to develop centrifugal force.
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,
causing an increase in energy use.)
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 some solar submersibles
work this way.
Positive Displacement Pump - Any mechanism that
seals water in a chamber, then forces it out by reducing the
volume of the chamber. Examples: piston, diaphragm, heli-
cal rotor, vane. Used for low volume and high lift. Contrast
with centrifugal. Synonyms: volumetric pump, force pump.
Priming - The process of hand-filling the suction pipe
and intake of a surface pump. Priming is generally neces-
sary 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 or
a length of flexible tube.
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 that is still used
for extremely deep wells, including solar pumps as deep as
1000 feet.
Self-Priming Pump - See priming.
Submersible Pump - A motor/pump combination
designed to be placed entirely below the water surface.
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Surface Pump - A pump that is not submersible. It must
be placed no more than about 20 ft. above the surface of
the water in the well. See priming. (Exception: see jet
pump)
Solar Pump Components
DC Motor, Brush-Type - The traditional DC motor, in
which small carbon blocks called "brushes" conduct cur-
rent into the spinning portion of the motor. They are used
in most solar surface pumps and in some low-power solar
submersibles. The motor chamber must be filled with air
and perfectly sealed from moisture. Brushes naturally wear
down after years of use, and must be replaced periodically.
DC Motor, Brushless - High-technology motor used in
more advanced solar submersibles. An electronic system is
used to precisely alternate the current, causing the motor
to spin. See three-phase AC. A submersible brushless motor
is filled with water and requires no maintenance.
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) pro-
duces proportionally reduced speed, and causes no harm to
the motor. Contrast: induction motor
Induction Motor (AC) - The type of electric motor used
in conventional single-phase AC water pumps. It requires a
high surge of current to start, and a stable voltage supply,
making it relatively expensive to run from by solar power.
See Inverter.
Linear Current Booster (LCB) - An electronic device
which varies the voltage and current of a PV array to match
the needs of an array-direct pump, especially a positive
displacement pump. It allows the pump to start and to
run under low sun conditions without stalling. Electri-
cal analogy: variable transformer. Mechanical analogy:
automatic transmission. Also called pump controller. See
pump controller .
Maximum Power Point Tracking (MPPT) - An added
refinement in some linear current boosters, in which the
input voltage tracks the variations of the output voltage of
the PV array to draw the most possible solar power under
varying conditions of temperature, solar intensity and load.
Pump Controller - An electronic device that controls
or processes the power to a pump. It may perform any of
the following functions: stopping and starting the pump;
protection from overload; DC-to-AC conversion; voltage
conversion; power matching (see linear current booster).
It may also have provisions for low-water shutoff and full-
tank shutoff devices, and status indicators.
Errors excepted and possible alterations without prior notice.
Water Well Components
Borehole - Synonym for drilled 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 is protected by a water-tight seal.
Drop Pipe - The pipe that carries water from a pump in a
well, up to the surface. It also supports the pump.
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 in the earth.
Pitless Adapter - A special pipe fitting that fits on a well
casing, below ground. It lets the pipe 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 cas-
ing. This is done by using a 1" threaded pipe as a handle.
Safety Rope - Rope used to secure the pump in case of
pipe breakage.
Submersible Cable - Electrical cable designed for
in-well submersion. Conductor sizing is specified in square
millimeters, or (in North America) by American Wire Gauge
(AWG) in which a higher number indicates smaller wire. It
is connected to a pump by a cable splice.
Well Seal - Top plate of a 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 document on which well characteris-
tics are recorded by the well driller. In most states, drillers
are required 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 well owner and
the public. Synonym: well record.
Drawdown - Lowering of level of water in a well due to
pumping.
Drawdown Level - Depth to the water surface in a well
while it is being pumped.
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.
Manual | LORENTZ PS Pump Systems