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few recommendations for water pumping: If
your AC water pump is larger than 1 horsepower, and it will operate more than a
few hours a day, then consider operating the AC pump on its own independent
electrical system.
The
starting currents for water pumps with AC motors are enormous. The starting
current of an AC pump can cause the inverter to shut down as a result of an over
current condition, requiring a manual reset of the inverter.
Therefore removing this load from the primary electrical system is
recommended to improve overall reliability. A
1-hp DC water pump can operate directly off the battery bank and does not
interfere with the inverter. The DC motor will not cause the inverter to shut
down due to an overload. DC
pumps are more expensive to purchase than AC pumps but you must factor in the
cost and impact on the entire system.
It might turn out that the configured system incorporating the DC pump
lowers the overall cost of the system. If
the house or farm has an AC pump already in place it still may save you money
and headache to give the pump to a neighbor and install a DC or engine driven
pump. We
recommend against using the AC generator (as part of the solar electric system)
to charge batteries and power the AC pump or other large power tools.
If you prefer to use an AC pump and possibly have other tools such as arc
welders then use the AC generator to power these tools directly and separately
from the Solar hybrid system.
This issue at hand is voltage and frequency regulation of the AC
generator. The AC pump motor and the inverter are sensitive to variations in
frequency and voltage.
So too many appliances operating off the AC generator can cause the
voltage and frequency to shift and damage the inverter and AC pump.
Typically the AC pump is more sensitive than the inverter. It
is far more reliable and fuel efficient to have an engine drive the pump
directly and bypass both the generator and motor.
Fuel consumption can be cut in half.
Voltage and frequency regulation is no longer an issue.
The engine can be configured to start and stop automatically.
An engine drive can provide water 24 hours a day.
It is the simplest of systems. The
other choice is to use a dedicated PV system (either a tracking or a fixed
position array) powering the pump without a battery.
Either a brushless DC motor or an AC motor with an inverter drive.
The brushless DC motors tend to be more efficient than the AC motors with
inverter drives especially when DC current boosters are used.
The dedicated AC motor inverter drive optimizes the power from the PV
array for efficient operation. Water
towers or pressurized water tanks are used on these solar systems to provide
water at night, so batteries are not required. Pumping
systems are coming soon to Polar Power |