7550000G
Copyright © Liberty Pumps, Inc. 2022 All rights reserved.
9 | EN
3-Phase Pump Rotation Verification
Verify 3-phase pumps for correct rotation prior to installing
pump(s) in basin. To change rotation, reverse any two of the
three power leads to the pump (not the ground). Code the
wires for reconnection after installation.
3-phase power uses three separate alternating currents that peak
at different integrals. With pumps that are powered by 3-phase
electric, the phase sequence of the motor must match the phase
sequence of the power source. When the phase sequences match,
the pump operates properly. However, when the phases are out of
order, the pump runs backward (i.e., the impeller rotates in the
wrong direction). This causes an extreme loss of performance and
could raise the current draw, which could result in tripping an
overload or circuit breaker.
To ensure that the power to the pump is installed correctly, always
verify proper rotation
before
lowering it into the basin. If the
pump is rotating in the wrong direction, turn off the power and
reverse any two of the three power leads to the pump (not the
ground). This reverses the phase sequence and corrects the pump
rotation.
For 3-phase pumps, rotation must be clockwise when
looking from the top of the pump. The correct direction is also
stamped on the bottom of the volute.
Discharge
Make all discharge connections. A check valve is required to
prevent the backflow of liquid after each pumping cycle. A gate
valve should follow the check valve to allow periodic cleaning of
the check valve or removal of the pump. The remainder of the
discharge line should be as short as possible with a minimum
number of turns to minimize friction head loss. Do not reduce the
discharge to below the pump outlet size. Larger pipe sizes may be
required to eliminate friction head loss over long runs. Contact
Liberty Pumps or other qualified person if questions arise
regarding proper pipe size and flow rates.
Pressure Sewer Applications
A redundant check valve assembly consisting of a curb stop and
check valve must be installed between the pump discharge and
the street main, as close to the public right-of-way as possible, on
all pressure (force main) sewer installations to protect from system
pressures. The curb stop valve is necessary to isolate the site from
the pressure sewer while the check valve provides redundant
protection against potentially detrimental backflow. All valves and
fittings should be rated for at least 200 PSI service. See Liberty
Pumps line of CSV-Series Curb Stop/Swing Check Valve
Assemblies and CK-Series Connection Kit.
Vent
The fiberglass basin provided with the system must be completely
sealed and properly vented per local health and plumbing code
requirements. If the system is to be vented through the inlet to an
existing building vent stack, there must be no traps between the
system inlet and the nearest building vent stack connection
(option 1). If this is not possible or desirable per the application, a
standalone vent can be installed in tank side (option 2) or a vent
flange or grommet can be installed in a hole cut into the cover
(option 3).
Correct Impeller Rotation
BOTTOM VIEW
TOP VIEW
Bulkhead
Connection
Pump Station
Compression
Adapter
Fitting
Curb Box
Compression
Adapter
Fitting
Valve Extension
Rod Shown
Curb Stop Valve/Swing
Check Valve Assembly
To Pump
To Main
Flow
Grade
option 1
option 2
option 3
Discharge
ground level
Sewage line
