6850000C
Copyright © Liberty Pumps, Inc. 2020 All rights reserved.
7 | EN
Preparation
Always disconnect pump(s) from power source(s) before
handling or making any adjustments to either the pump(s),
the pump system, or the control panel.
Prepare Sump [Basin]
If replacing a previously installed pump, prepare the basin by
removing the old pump and cleaning any debris from the basin.
Inspect all remaining equipment in the basin including guide rails,
piping, valves, and electrical junction boxes (if present) and repair
or replace as appropriate. Ensure that control hardware such as
floats or pressure transducers are clean, properly adjusted, and in
good working order.
Pump installation should be at a sufficient depth to ensure that all
plumbing is below the frost line. If this is not feasible, remove the
check valve and size the basin and/or adjust pump differential to
accommodate the additional backflow volume. Consult Liberty
Pumps for details on how this should be done.
Pump Control and Alarm Floats
The water level in the basin is determined by the placement of the
control floats and should be positioned such that the motor
housing is completely submerged to properly cool the motor. If
full submersion is not possible, the minimum water depth must be
no less than 13 inches as measured from the bottom of the pump
legs. The upper water level should be positioned to minimize
pump starts. The alarm float must be above the turn-on float
switch but below any inlets. No control should be set above the
inlet to the basin.
Set the second (turn-on) control above the lower turn-off control.
The exact distance between the two floats must be a compromise
between a frequent pumping cycle (10 starts per hour max) to
properly manage sewage level, and a longer pump run duration
per start, which maximizes energy efficiency. This distance must
be determined by the engineer, depending on the conditions of
the application.
Cutter and Impeller Free Movement Check
Wear Personal Protective Equipment as exposed bottom has
sharp edges.
Do not connect any power to pump until this check is complete.
Manually rotate the cutter to check that it spins freely with very
little resistance. The cutter is located on the bottom of the pump.
The cutter can be carefully rotated by hand, or rotated by
inserting a tool into the cutter bolt. If rotating by hand, wear
protective gloves as the cutter and cutter plate have sharp edges.
The pump can remain upright or can be laid down on its side for
easier access to the cutter. Besides verification that the cutter and
impeller are freely spinning, rotating the cutter helps to lubricate
the shaft seals if the pump has been non-operational for more
than a week. It is recommended to rotate the cutter 5–10 full
rotations.
Installation
All installation and maintenance of pumps, controls,
protection devices, and general wiring shall be done by
qualified personnel.
All electrical and safety practices shall be in accordance with
the National Electrical Code
®
, the Occupational Safety and
Health Administration, or applicable local codes and
ordinances.
Electrical Connections
With main power disconnected, complete pump and control
wiring connections per wiring diagrams included with the control
panel and Figure 1/Figure 2 as applicable. All wires should be
checked for unintentional grounds with an ohmmeter after the
connections are made.
Thermostat and Seal Failure Connections
Verify thermostat wires are connected in series with the contactor
and that seal fail probes are properly connected and relay
sensitivity properly adjusted. Connections are provided on the
terminal strip inside the Liberty Pumps control panel.
Seal leak relay setup:
Turn the potentiometer dial clockwise until
the red light turns on, then turn the dial counterclockwise until the
red light turns off. The tick marks on the seal leak relay are for
reference only. The seal leak adjustment dial should be set to
around 75 (range is 75 to 125).
3-Phase Pump Rotation Verification
Check 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 three 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 power leads. This reverses the phase sequence
and corrects the pump rotation.
Rotation must be
counterclockwise when looking from the bottom of the pump.
RISK OF ELECTRIC SHOCK
RISK OF ELECTRIC SHOCK
Correct Impeller Rotation
BOTTOM VIEW
