Franklin Electric VS 4 Serie Manuel Du Propriétaire page 5

9. A three-phase pump does not require a motor control
box . Fig. 4 shows a typical wiring diagram for a 3-
wire, three-phase installation. A magnetic contractor
with 3-leg protection having quick-trip ambient
compensated overload relays must be used.
FIGURE 4 - 3-Wire, 3 Phase, 1-1/2 thru 50 HP
Pump Wiring Diagram
Circuit Breaker OR
Fused Disconnect Switch
Incoming 3 Phase Power
10. Use an ohmeter to make continuity and insulation
checks after the installation is completed.
11. Place the additional pump nameplate onto the
submersible label and place both onto disconnect
switch or circuit breaker box for future reference.
WELL TEST
Check the pump and well performance before making
the fi nal connection to the discharge system.
1. Install a gate valve on the end of the pipe. Partially
open the valve.
2. Start the pump.
3. Open valve gradually to give full fl ow.
4. If the discharge is not clear, let the pump run until
water clears. If water does not clear in 30 minutes,
stop the pump and take the necessary steps to correct
the condition. After the water has appeared clear,
check for sand by discharging into a clean bucket or
suitable container.
5. Close valve until maximum required system fl ow
rate is obtained (this should correspond to the cut-
in pressure of the pressure switch). Ensure that
the output of the pump at this setting is not greater
than the yield of the well. This can be checked by
monitoring the well drawdown level and ensuring tht
the level is stable at the maximum required system
fl ow rate.
C A U T I O N
Never run pump unless it's completely
submerged in water. If run without water, the pump
and motor could be damaged. Note also that air
drawn into the pump can cause an airlock under
certain conditions.
Pressure Switch
Magnetic Contactor w/
3-leg protection having
quick-trip ambient
conpensated overload relays
3 Phase Submersible Motor
LOW-YIELDING WELL
A low-yielding well exists when the output from the pump
is greater than the yield of the well. It can reduce the
water level to the suction screen so that a mixture of air
and water enters the pump. Pumping may stop since the
pump cannot generate pressure with insuffi cient water.
In this case, the column of water already in the drop pipe
holds the check valve closed and an airlock may develop
inside the pump. Because the conditions ensure neither
adequate lubrication of the pump nor proper cooling
for the motor, damage can result if power is not cut off
quickly. use one or more of the following methods to
correct and/or protect this installation.
1. Install additional length of drop pipe to place pump
lower in well if possible.
2. Install a Franklin Pumptec or similar electronic
drawdown sensor.
3. Install a fl oatless liquid level control. This device
consists of an electrical relay activated by currents
fl owing through the ground-return circuits of
electrodes hung in the well. The lower(STOP)
electrode, just above the pump, ensures that the
water level can never be pumped down to the suction
screen. The upper(START) electrode, just below
the lowest static water level, ensures that the pump
can start again as soon as the well has recovered.
A fl oatless liquid level control works in series with
the pressure switch. Refer to the manufacturers
instructions provided with control.
4. Install a fl ow control valve in the discharge line
upstream from the pressure switch. This restricts
the output from the pump without affecting the rate
that water can be drawn from the pressure tank.
Nevertheless, a heavy demand for water could
empty the pressure tank, so a tank with a bonded
diaphragm, air cell, or water bag is recommended.
5. Install a smaller pump to avoid over pumping the well.
Have dealer size pump to the well yield.
6. Install a low-pressure cut-off switch. A low pressure
cut off switch, or a pressure switch with such an
arrangement built in, protects a shallow-well pump
from losing its prime, but it does not always provide
satisfactory protection to a submersible pump from
the effects of over pumping the well. This is because
it responds to a loss of pressure at the surface,
which may occur after an air lock has formed inside
the pump. We recommend either a fl oatless liquid
level control or a fl ow control valve, in that order,
in preference to a low-pressure cutoff switch as
protection against over pumping.
3