Pumping Application Notes
Directory
1.0 Motor Drive/Pump Products
1.1 Direct Solar Driven Systems
1.1.1 Usual operation
1.1.2 Voltage controlled
1.1.3 Voltage conversions
1.1.4 Capacitive kick systems
1.2 Battery backed pumping systems
1.2.1 Continuous duty systems
1.2.2 Voltage conversions
1.2.3 Timed operations
1.2.4 Dependable flow rate required - Constant Voltage
1.2.4.1 Up Conversions
1.2.4.2 Down Conversions
1.2.5 Float switch/LVD control
1.2.5.1 Direct Drive Systems
1.2.5.2 Capacitor used for kickstart
1.2.5.3 Battery Backed
1.3 Integrated Pump Control Centre
1.4 Wind/Water Driven Systems
1.4.1 Series Operation
1.4.2 Shunt Controlled
1.0 Pump Products
It is important to know that these products perform a true power conversion.
As the voltage on the motor drops due to lack of solar power, the current from the solar
panels increases by almost the exact same percentage as the drop in voltage from the
panel maximum power point voltage. This is Linear Current Boosting at its finest.
For example, if your pump is running in partial sun at 8 V from a panel that has a
MPPT of 16 V, (motor at 1/2 panel voltage) the current will be 2 X the panel current. If
the panel is producing 1 amp at the reduced sunlight, the motor current will be 2 amps,
providing great torque to keep pumping, even in reduced sunlight.
1.1 Direct Solar Drive
1.1.1 Usual Operation
The simplest type of system is to connect the solar panel directly to the motor.
This system works well but suffers from low start-up torque in reduced sunlight.
To get around the low torque problem, a common set-up is a typical solar panel
running an LCB type device running a motor/pump. This is usually set up as seen in
Figure 1. There may be a float switch in line with the motor.
For these applications our models PPT12/24-3, PPT12/24-7V or PPT12/24-15 are
the best choices. Motor power up to 30 - 40 amps is available by using the 30 amp
charge controller (model PT12/24-30) in its motor drive mode.
Features:
Single unit 12/24 V
High voltage units available
Float/dry switch control
Transient protection varistors as standard equipment
Very high efficiency in a small package
Maximum Power Point Tracking (MPPT)
Model PPT12/24-7 can handle 7 amps easily and is cost effective enough for
very serious consideration in any 3 amp systems, making it inexpensive in a 7 amp
system.
1.1.2 Voltage Controlled
A problem discovered with the usual operations is an application where good
water flow is needed even on bad sun days. See Figure 2. This has been addressed
before by adding solar panels for the power to pump on poor days, but now on good days
the motor is badly overpowered - burning out the motor.
Our large pump driver Model PPT12/24-15 and PPT12/24-7V features voltage
control of its output voltage. Now you can add all the solar panels you want for bad
days, and you will never overvoltage the motor on a good day.
Features:
Voltage Controlled
Single unit 12/24 V
High voltage units available
Float/dry switch control
3 heavy duty varistors, not one, for true transient protection.
NEMA 4 enclosure
Maximum Power Point Tracking
Very high efficiency in a small package
1.1.3 Voltage Conversions
For some application, the panels must be a long way away from the motor, itself
perhaps a long way from the holding tank. See Figure 3.
Special versions our pump drivers are readily available and can perform voltage
conversion using their voltage control capability, where the panel voltage can be much
higher than the motor voltage without over voltaging the motor. For example, 48 V panels
running a 12 V motor while Maximum Power Point Tracking and transforming ALL the power
to your 12 V motor.
Advantages:
Easier to match panel power to motor power requirement. For instance
ie: If you need qty. 5 12 V panels to run a 24 V motor, buy 5 instead
of the 6 normally required for a series - parallel connection to connect
directly at 24 V.
Use much smaller gauge wire for your panel wiring, saving both in cost as
well as the aggravation of handling AWG # 4 wire instead of AWG # 12 over a
few hundred feet. These savings alone can pay for the controller.
Low current float switch on/off allows wiring with, for example, telephone
cable over a few hundred feet to the float switch in your holding tank instead
of another long distance run of heavy gauge wire to have the float switch
in the tank break the motor power.
Features:
Voltage controlled
Float/dry switch control
3 heavy duty varistors, not one, for true transient protection
NEMA 4 enclosure
Very high efficiency in a small package
Maximum Power Point Tracking
1.1.4 Capacitive Kick Systems
Some pump types, like some displacement or jack pumps are good pumps that
work great once you can get them started, but require a kick to get them started. This is
typically done by charging a BIG capacitor to high panel voltage, then switching into the
motor. The motor starts with a KICK, then its own inertia keeps it going with the lower
energy available from the solar panel.
Our charge controller modified (- CS on model number) can perform pump
motor capacitive kick to get it moving, followed by MPPT linear current
boosting for maximum motor power to keep it pumping, and float switch control all in a
single integrated control power package. See sections 1.2.5.2 and 1.3.
Figure 4 illustrates the system set-up. Our charge controller is set up with a BIG
capacitor on its battery terminals, the float switch on its LVD terminals, and the motor
on its load terminals.
The unit charges the capacitor to a set voltage (user defined), then when the
voltage gets there, the "LVD" relay closes, connecting the capacitor to the motor which
starts with a kick. The unit then follows the kick with the panel power (with MPPT) to
keep the motor going. If the motor stalls (i.e.: motor voltage falls to low), the "LVD"
relay opens, the capacitor charges again, and we kick start the motor again. Float switch
control is attained by direct control of the on/off relay. Current limiting ensures the
motor will not burn out. This will ensure your pump starts without fear of burning out
the motor!
Additional features are motor voltage indication and both voltage and current
limiting, allowing designs for excess panel power for "off" days without fear of burning
out the motor on good days.
Features:
One controller does it all
Float/dry switch control
Heavy duty transient protection
Maximum Power Point Tracking
Voltage conversion ability
Section 1.2: Battery Backed Pumping Systems
1.2.1 Continuous Duty Systems
Some pumping applications require pump power at any time. A battery is
typically used to supply this power at "off" times. See Figure 5.
Solar Converters Inc. MPPT charge controllers can maximize your charge
current and possibly even save a solar panel in your system. If we save you even 1 solar
panel, we have paid for ourselves a few times over. It also features float/dry switch
control.
Features:
Battery fuse and LVD already in system
Float switch control
Excellent care and feeding of the battery with dual float PWM charge Technique
Maximum Power Point Tracking
Very high efficiency in a small package
1.2.2 Voltage Conversions
For some applications, the panels must be a long way away from the battery,
itself perhaps a long way from the holding tank/motor. See Figure 6.
Special versions of Solar Converters Inc. charge controllers, are readily available
that perform voltage conversion, where the panel voltage can be much higher than the
battery voltage without over voltaging or over charging the battery. For example, 48 V
panels charging a 12 V battery to power a 12 V motor/pump.
Advantages:
Easier to match panel power to motor power requirement. i.e.: If you need qty 5
12 V panels to run a 24 V motor, buy 5 instead of the 6 required for series
parallel connection to connect directly at 24 V.
Use much smaller gauge wire for your panel wiring, saving in both cost as
well as the aggravation of handling, for example, AWG # 4 wire instead
of AWG # 12 over a few hundred feet. These savings alone can pay for the
controller.
Low current float switch on/off allows wiring with, for example, telephone
cable over a few hundred feet to the float switch in your holding tank
instead of another long distance run of heavy gauge wire to have the float
switch in the tank break the motor power.
Features:
Battery charge indication
Battery fuse and LVD already in system
Float/dry switch control
3 heavy duty varistors, not one, for true transient protection.
Heavily transient protected
Excellent care and feeding of battery with dual float PWM charge technique
Maximum Power Point Tracking
Very high efficiency in a small package
1.2.3 Timed Operations
Examples of timed pumping functions are pond aeration and fountains. Solar
Converters Inc. charge controllers feature an external control of the LVD function
i.e.: your motor on/off.
By connecting the system up as shown in Figure 7 several time and cost saving
features are incorporated,
1) The charge controller takes care of all the battery with Maximum Power Point
Tracking and dual float PWM charging i.e.: more charge current from your panels and
perhaps fewer panels required, hence expense to your system.
2) The "LVD" relay is now controlling the motor on/off as commanded by the
timer and/or switch. This timer can be set for whatever on and off time you desire.
Quartz timers and dual event timers are readily available from Newark, for example.
Features:
Battery charge indication
Battery fuse and LVD already in system
External LVD control gives float switch control
3 heavy duty varistors, not one, for true transient protection
Heavily transient protected
Excellent care battery with dual float PWM charge technique
Maximum Power Point Tracking
1.2.4 Dependable Flow Rate Required - Constant Voltage
Some applications require a constant voltage on the pump to maintain flow and
head as the battery discharges. We make 2 forms of constant voltage regulators:
Up converters to increase the voltage on the motor from a lower voltage battery, and
Down converters to decrease the voltage.
1.2.4.1 Up Conversion
Some battery pumping applications suffer from reduced flow and head as the
battery discharges. To address this problem, connect the system as shown in Figure 8.
By connecting the system in this fashion, and using Model CV 16/28-10 (different
voltages are available) the following capability are found.
Advantage:
Maintains a constant voltage, hence pumping performance even as the
battery discharges down to its LVD point.
Can boost and regulate voltage substantially different,
for example, operate a 24 V motor at 28 V from a 12 V battery or models
can operate a 48 V motor from a 24 V or 12 V battery.
Contact Factory for your requirements.
Features:
Single unit dual voltage output
NEMA 4 enclosure
Very high efficiency in a small package
See Section 1.2.5 for float switch control.
1.2.4.2 Down Conversion
Some battery pumping applications suffer from reduced flow and head as the
battery discharges. To address this problem, connect the system as shown in Figure 8.
By connecting the system in this fashion, and using Model EQR 12/24-20 the following
capabilities are found.
Advantage:
Maintains a constant voltage, hence pumping performance even as the
battery discharges down to its LVD point.
Can reduce and regulate voltage substantially different, for example,
operate a 24 V motor at 28 V from a 48 V battery or operate a 12 V motor
from a 24 V or 48 V battery. Contact Factory for your requirements.
Features:
Single unit dual voltage output
NEMA 4 enclosure
Very high efficiency in a small package
See Section 1.2.5 for float switch control.
1.2.5 Float Switch/LVD Control
Any of the pumping systems from battery can benefit from the LVD / Float switch
module. Available options include temperature and current compensation of units LVD
points.
1.2.5.1 Direct Drive
Figure 9 illustrates the connection for float switch control of a direct drive pump
system. This mainly finds application in larger systems or when there are large distances
between system components. It includes remote and local on/off control of the motor.
Features:
Simple hookup and control
Hysterisis on float switch module allows for capacitive motor kickstart
Single unit 12/24 V model
Remote and local motor on/off control
1.2.5.2 Capacitive Kick Systems
Some pump types, like some displacement or jack pumps are good pumps that
work great once you can get them started, but require a kick to get them started.
Figure 10 illustrates another function of this unit (- CS on model number).
For motors with high starting torque requirements which could run at low solar
power, this unit can be used. The unit can charge a large capacitor to the panel voltage,
then the unit switches the capacitor into the motor, creating a high starting torgue at full
voltage. Then the current from the panel keeps the motor going. If the motor stops, the
unit opens the motor circuit, the capacitor charges again, kick starts the motor and the
panels again run the motor.
This mode of operation is available using the LVD float switch on most systems,
however, using a Solar Converters Inc. charge controller modified (- CS on model
number) can perform pump motor capacitive kick, with follow-on MPPT for maximum motor power,
and float switch control as well in a single integrated power control package.
See Section 1.1.4.
1.2.5.3 Battery Backed Pumping System
This devices performs battery fusing, LVD, on/off and float switch control of the
motor/pump driven from a battery. When connected as shown in Figure 11, the LVD unit
takes care of all the battery/motor interface concerns and gives local and remote float
switch control of the motor.
Features:
Fused battery
Integral LVD
Local and remote float switch control
1.3 Integrated Pump Control Centre
This specialized product marries together several features into one turnkey
complete product. It is usually a custom device aimed at specific pumps and
applications.
Features:
Single control box for all functions
Ease of wiring and maintenance
Local and remote control of motor/pump
On/off or float/dry switch control
Surge protected
Multiple output voltages
Pump on/off indicator
Capacitive kick start circuits
Examples:
1) Constant voltage up converter combined with a LVD/float switch control.
This device takes the voltage from a 24 V battery source and provides a constant 60 V @
6 amps to operate the pump motor. It has surge capability to 20 amps as well as local
and remote motor on/off control. This is all mounted in an enclosure so all you hook up
are the motor leads, battery leads and float switch.
2) A capacitive kick with Maximum Power Point Tracking with its big start
capacitor, motor current and voltage limiting, as well as remote and local float switch
control, motor speed indication and motor on/off indication. This is all mounted in an
enclosure so all you hook up are the motor leads, PV leads and float switch.
1.4 Wind and Water Driven Systems
Solar Converters Inc. solar driven pump drivers, perhaps slightly modified, can
be used to optimize the power transfer from your wind or water driven turbines as well.
This is a new market for us but some of our products are beginning to be used for these
systems. Please contact the factory to determine if your wind or water pumping needs
may be met with our units.
1.4.1 Series Operation
These units work by transforming the voltage from the PV voltage to the load
voltage. They can also work by transforming your turbine DC voltage to the motor
voltage over a substantial input voltage differential pulling maximum power from the
turbine. Models may be ordered that take substantially higher input voltage up to 200 V
on the input to account for no-load voltage swing, all the while putting out 12 V nominal
for your pump motor.
These units work identical to their solar counterparts and the various operation
modes and features are available.
1.4.2 Shunt Controlled
One answer to the input voltage swing as the load is reduced is to use our Load
Diversion Controller. This unit is a 0 - 100% infinitely self adjustable PWM shunt
regulator that keeps the motor voltage constant by diverting the turbines power to a shunt
resistor to perhaps heat water.
During normal operation, the unit is "transparent". As the turbine attempts to
take the motor voltage over set voltage, the PWM regulator steals the excess current,
regulating the motor or turbine voltage to a set maximum. This means that your motor
will not be overdriven or burnt out from excess wind power. It can also be used to
prevent turbine rotor overspeed and excessive voltage at no load when the float switch
turns the motor off.
Note: Information contained herein may be updated/changed at anytime without notice.