8 | EN
Copyright © Liberty Pumps, Inc. 2022 All rights reserved.
7550000G
Prepa ra tion
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.
Install 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. The
upper water level should be positioned to minimize pump starts.
The alarm float should be above the turn
-
on float switch but
below any inlets.
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 shall be
determined by the engineer, depending on the conditions of the
application.
Prepare Basin
If replacing a previously installed pump, prepare the basin by
removing the old pump and cleaning all 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.
When installing the pump into an existing basin with a guide rail
system, make certain the pump seats properly. Some vaults have
angled bottoms that might interfere with the pump legs. In this
application, the pump’s legs should be trimmed as required.
Liberty Pumps recommends leaving a portion of the leg so that
the pump will stand upright when placed on the floor. Refer to
2.
Figure 1. Cut-off Point 3–7
hp Pumps
Figure 2. Cut-off Point 10–15
hp Pumps
Cutter and Impeller Free Movement Check
Wear Personal Protective Equipment to protect hands as
cutter blades have extremely sharp edges and present a
serious cutting hazard.
Do not connect any power to pump until this check is
complete.
Manually rotate the cutter and impeller to check that
they spin 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, be sure to 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 and impeller 5–10 full
rotations.
Insta lla tion
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.
For pressure sewer applications
, verify a Redundant Check
Valve Assembly (curb stop and check valve) is installed
between the pump discharge and the street main, as close to
the public right-of-way as possible, on all installations to
protect from system pressures.
Electrical Connections
With mains power disconnected, complete pump and control
wiring connections per wiring diagrams included with the control
panel and
section. Verify connections. Check
all wires for unintentional grounds after the connections are made.
RISK OF ELECTRIC SHOCK
3” [76.7 mm]
RISK OF SERIOUS INJURY OR DEATH
RISK OF ELECTRIC SHOCK
1-3/4” [44.5 mm]
