Director,
T.E.(Terry)
Manning,
Schoener 50,
1771 ED
Wieringerwerf,
The
Tel:
0031-227-604128
Homepage:
http://www.flowman.nl
E-mail:
(nameatendofline)@xs4all.nl : bakensverzet
Incorporating
innovative social, financial, economic, local administrative and productive
structures, numerous renewable energy applications, with an important role for
women in poverty alleviation in rural and poor urban environments.
"Money is not
the key that opens the gates of the market but the bolt that bars them"
Gesell, Silvio The
Natural Economic Order
Revised English
edition, Peter Owen, London 1958, page 228
Edition 9:
The following pages are about sealing the well, lightning and freeze
protection and the use of accessories. If you are more interested in other
aspects concerning installation, please return to the installation index.
It is most important your bore-hole be completely
sealed off once your Solar Spring pump has been installed. This is to stop
pollution of the water in the bore-hole through events such as animals and
insects falling down; soil, sand, dirt or animal dung entering the water and/or
the bore-hole, and, finally, to stop the water pumped from going back down the
bore-hole.
We recommend that the bore-hole lining pipe be allowed to protrude several
centimetres above ground level; that concrete borehole exit support be made
sloping from the borehole outwards, so as to ensure drain off water from around
the bore-hole.
In particular, it is necessary to seal off, as carefully as possible, the
centre hole where the feed pipe, electric cable, safety rope, and, where used,
sensor cables, pass, or use a pitless adapter.
At sites considered highly exposed to lightning which can damage PV panel by-pass diodes and internal components of Sunprimer electronic controllers, a lightning conductor made from a large horizontal conductor placed at a reasonable height above the panels and connected at each end through two good conductors to two good earth contacts placed a reasonable distance away from the equipment, may be used. Such lightning protection should only be installed by expert electricians, scrupulously respecting applicable safety regulations. The basic protection so obtained can be further improved by protecting all the electrical wires from the panels to the controller and from the controller to the pump, by housing them in strong metal pipes similar to those used by plumbers, and connecting the metal pipes and the metal box of the controller to earth contacts placed a long way away from those of the lightning conductor. It is not however considered possible to eliminate all risk of lightning damage. Insurance coverage for damage by lightning is usually available.
Ground the metallic structure of your solar array. Use a minimum of one 3m (8 foot) copper plated ground rod, or equivalent, preferably in moist earth. In an area of high lightning exposure, where the earth may be very dry (non-conductive) we recommend running a length of BARE copper ground wire in your pipe trench, perhaps 30m (100 feet) beyond the ground rod. This will help discharge static charges into dry earth. If you have a steel well casing, you may use it as your ground rod. Drill and tap a hole to make a strong, bolted connection to the casing.
DO NOT GROUND either the positive or the negative
electrical wires. We have found the best lightning protection results from
grounding the metallic structure only and NOT grounding the power wiring.
Exception : You may connect the pump to a battery based home power system with
a negative ground. If the wiring distance to the pump exceeds 50 feet (17m) -
particularly in a high lightning area - the use of DC rated surge protection
devices is recommended.
EXCEPTION. Where system grounding is unconditionally required by electrical
authorities, ground the yellow/green PV array negative lead on the controller.
Do NOT break its continuity in your array disconnect switch. Where your
system is so grounded, a DC rated surge protection device MUST be fitted. We
believe electrical grounding INCREASES the risk of lightning damage and should
be avoided wherever legally possible.
ADDITIONAL LIGHTNING PROTECTION may be advisable in case of:
a)Isolated locations on high ground in severe lightning areas
b)Poor grounding potential because of dry, rocky, or poorly conductive soil
c)Wire runs between arrays and well-heads or between controllers and remote
float switches exceed 30m (100ft).Fit an appropriate surge protection device.
In case of poor grounding potential, bury gauge 6 (or double gauge 8) BARE
copper grounding wire in a trench at least 30m (100ft) long, with one end
connected to the array structure.
Sunprimer Mk II controllers will automatically switch your pump off
where the feed pipe system is blocked because of freezing or for any other
reason. However, since the pump will then not pump any water, steps should be
taken to try to avoid the freezing of the water in your system.
One method is to bury all piping below the frost line (refer to the use of
pitless adapters in the preceding pages). Another method is to drill a tiny
"weep hole" in the drop pipe below frost line. This will cause a
constant, but small, leakage, causing the pipe to drain slowly after the pump
stops. This works well if the distance from the well to the tank is short, and
the pipe spills into the top of the tanks.
WARNING
!! USE OF HIGH VOLTAGE PANELS IN VERY COLD AREAS.
The voltage of PV Panels increases as temperature decreases. The
transistors used in the Sunprimer Mk II unit are suitable for voltages up to 80V,
which allows, in the case of use of 4 conventional PV panels each with a nominal
voltage of 12V, protection to -20 degrees centigrade. As panels warm up when
exposed to the sun, -20 degrees C. is considered safe for utilisation in any
part of the world. Some new panels currently (November 1996) appearing on the
market, such as the BP 590 modules, have a nominal voltage which is higher than
12V. This may mean that the voltage limits of the Sunprimer transistors reach
their maximum at -5 degrees C. In very cold areas, it may in such cases be
advisable to place a voltage limiter between the panels and the Sunprimer unit,
and/or to consult your supplier.
Sets of pressure pre-sostate groups may be connected
to the pump for automatic household water supply, both where the Solar Spring
is used directly connected to PV panels or where it is used (with Mk I/e
controllers) together with battery sets. This 0equipment MUST operate on the
two wires of the smallest cable coming out of the Sunprimer controller. When
the two wires are in contact with one another or in an electrical circuit, the
Sunprimer controller cuts current flow to the pump. When the two wires are not
in contact with one another, or not in circuit, the Sunprimer controller
supplies current to the motor.
TYPE
OF SWITCH REQUIRED
While
most float-switch units cut current on contact and incorporate good quality
switches, only a few pre-sostate groups currently in commerce offer the
possibility of switching the pump off when contact is made as is required by
the Mk I/d controller. Further many presostates in commerce seem to incorporate
extremely poor quality switches. Fortunately, good quality presostates with the
required connections are available in equipment designed for use with
compressed air. Pre-sostates used for compressed air, fitted where required
with an appropriate water filter, are therefore warmly recommended. They must
be connected to the dedicated wires of the controller and NOT to the
panel/controller cable.
WARNING!
It is prohibited to make a float switch or pre-sostate connection by intervening
on the electric cable joining the PV panels with the controller unit. The small
cables from the controller have been expressly dedicated for this purpose. If
either the pre-sostate used is of bad quality and/or the switch incorporated in
it is a bad quality one, then the emergency circuit of the controller will act
to cut all operations and protect the pump motor while the main transistor of
the controller itself may in some cases burn out. On- and off-switching must be
done using high quality switches with a rapid and precise opening and closing.
Switches which are slow and hesitant have a very high probability of burning
out the controller. This is true not only where the switch were to be placed on
the panel-controller cable but also, at least in some cases, where it is used
with the small controller wires. The difference in the probability of damage to
the controller itself is that while the panel cable is crossed by many amps,
the small dedicated controller cable is crossed by just a few milliamps and
external switches should therefore always be connected to the dedicated
controller cable and not to the main panel-controller cable.
Water
flow must in NO CIRCUMSTANCES be blocked by taps, valves or similar, as these
could cause a dangerous build-up of pressure within the pumping system.
An AC waterproof 30 amps single phase (two pole) on/off swtich may be
placed BETWEEN THE PV ARRAY AND THE Sunprimer controller. The switch should be
wired to disconnect the positive from each half of the solar array.
WARNING
!!
NEVER place a switch between the Sunprimer controller and the pump.
Use 24V-36V battery systems. 48V battery systems cannot be coupled to
the Sunprimer Mk II controller, and their use is not recommended.
Use ONLY deep-cycle batteries.
If the pump starts comfortably immediately after connection with the battery
system, the battery installation is in order. If the pump does not start, then
increase cable size and eventually use a pump with smaller cam.
The Mk II controller incorporates a battery protection function. 24V
battery systems are irreparably damaged if their voltage goes down to about
21.6V. The Mk II unit therefore cuts current to the pump motor when battery
voltage (for a 24V set) reaches about 22.4V, which indicates that the batteries
have lost 90-95% of their full charge.
If a voltmeter is placed in the circuit between the batteries and the Mk
II controller, the voltage shown with the pumped stopped will always be about
24V, whether the batteries are flat or fully charged. To find out whether the
batteries are flat and how flat they are, the voltmeter must be watched at the
moment the pump is switched on. If the voltage is slightly more than 22.4V, the
pump will start. The moment the voltage goes below about 22.4V the controller
will switch the pump off and try to start the pump again once every two
minutes.
Before
checking battery voltage on pump start-up, make sure there are no other
resistances in the circuit between the batteries and the controller, as these
could falsify the result.
To carry out a check on the operation of the pump using batteries, it is
usually enough to use a commercially available tester (amp-meter) in the pump
circuit.
If the newly installed pump does not produce water but absorbs the current
shown in the performance tables then either the pump is not submerged or it
cannot self-prime, in which case please refer to the section on testing after
installation.
If the newly installed pump starts but absorbs a
current which is higher than that shown in the capacity tables, or where a
safety switch or fuse jumps, AND the pump does not produce any water, then
either the feed pipe is blocked or the pump cannot start because the load is
greater than what the pump can handle. If the feed pipe is not blocked, then
the load on the pump must be reduced by doing the following IN THIS ORDER:
Reduce submergence
Reduce cable length
Increase cable size
Use a smaller cam size.
If the pump suddenly stops working after several years' service and is
not absorbing any current even though the rest of the system is in order, then
either the cable is broken or the motor brushes need replacing. To carry out a
check in such situation, a 10000 Ohm resistor has been placed inside the motor
in parallel with the brushes. If the overall electrical resistance of the
circuit is measured with a tester at the two external ends of the motor cable
BEFORE lifting the pump and the resistance is found to be about 10000 Ohm, then
we know the brushes need replacing. If, instead, we find a resistance which is
practically infinite, then we know the cable is broken.
If
the pump after a period of normal operation, absorbs the current foreseen in
the performance tables or a current which is slightly lower than that, but
fails to produce any water, then the water level in the borehole has gone down
and the pump is running dry. This will not harm the motor but will defeat the
reason for having made the installation in the first place.
If
the pump after a period of normal operation, absorbs a current which is higher
than that foreseen in the tables but produces no water, then the feed pipe is
blocked. The Mk I/e controller will act and automatically switch the pump off.
Where, as is usual, the Solar Spring is installed with a Sunprimer controller, switches or similar connected with optional equipment such as level sensors should be connected to the two wires of the smallest cable coming out of the Sunprimer controller unit. A number of electronic sensors can be used to help make your Solar Spring system more practical to use. Others may help you conserve your Solar Spring system.
The
Sunprimer controller has been expressly fitted with wires for sensors, amongst
which :
1) Float switches, which are used to switch off the pump (and therefore
further delivery of water) where the water tank, or other recipient or system
into which the water is fed, is full. The sensor switches the pump motor on
automatically when the water level drops. The float switch must make contact on
rise, to turn the pump off. If there is no contact, the pump is in ON mode.
This has been done in order to ensure that in case the float switch wires or
the float switch itself are damaged, the pump will continue working.
2) During interruptions of pumping operation, available power from the
PV panels is not being utilised. A device can, in such circumstances, be placed
between controller and panels to switch automatically over to the charging of
batteries for use with other equipment and/or for subsequent use with your
Solar Spring pumping system itself. Where batteries are coupled to the Solar
Spring pump, the pump can also be used at night or when irradiance is too low
to drive the pump directly. Storage of energy in the form of water is however
usually considered more efficient than battery storage.
3) Dry running. Your Solar Spring pumping system is unique in that it
can run dry, and water level sensors in the borehole are not necessary.
However, running dry would be a waste of energy, cause unnecessary aggravation
of wear and tear on the pump, and defeat the purpose of the installation. THE
PUMP SHOULD ALWAYS BE INSTALLED BELOW THE LOWEST SEASONAL LEVEL OF WATER IN THE
BORE-HOLE. This is always possible with Solar Spring pumps because they can
support very deep submergence.
When
the two wires of the smallest Sunprimer controller cable are connected with one
or more external devices such as switches, float switches, pre-sostates, they
enable pump operation to be controlled at a distance. The colours and the
polarities of the wires are unimportant, and the electrical currents involved
are just a few milli-amperes. If the two wires are not used, they should each
be separately well insulated.
As a user of a Solar Spring pumping system, you may wish to carry out
cost and benefit analyses in relation to the running of the Solar Spring
system. We are eager to cooperate with you in every way to help you build up
and elaborate your statistics. We always seek your authorisation to use your
data for general statistical purposes of interest to the general public. In
order to carry out such analyses, a minimum instrumentation is needed:
This is :
1) A water meter, to measure the water pumped by your Solar Spring system,
measured in cubic metres. Accuracy of the data, on a daily, monthly or seasonal
basis, will depend on the number of readings taken. More refined automatic data
logging equipment with accurate timing falls within the field of scientific
research, and is therefore outside the scope of the optionals foreseen in this
manual. We assure our strong support to Universities, testing organisations and
interested parties who wish to carry out detailed data logging programmes
directly connected with the use of the Solar Spring pumping system.
2) A simple electronic meter at controller and/or at motor point to measure
power input into the motor. Comments under 1) above apply to this meter too.
THE
TWO METERS LISTED ABOVE, WHEN USED TOGETHER OVER THE SAME TIME SPAN, WILL
SUPPLY INCONTROVERTIBLE EVIDENCE OF THE GLOBAL SUB-SYSTEM EFFICIENCY OF YOUR
SOLAR SPRING HORIZONTAL AXIS SUBMERSIBLE PISTON PUMP GROUP.
The
use of taps, valves and the like may have unforeseeable consequences and is
SEVERELY PROHIBITED. Water flow must be controlled by cutting the supply of
current to the pump motor.
Menu installation Solar Spring pumps.
Some recommended technologies.
List of attachments to the Model.
Typical list of graphs and
drawings.
List of abbreviations used.
List of key words.
Documents for funding
applications.