2399000D
Copyright © Liberty Pumps, Inc. 2020 All rights reserved.
7 | EN
Pump Control and Alarm Floats
The engineering drawings will generally specify the levels for
Pump ON, Pump OFF, and High Level alarm. If they are not
specified, the guidelines in Table 1 should be used to determine
float switch locations. The upper water level should be positioned
to minimize pump starts. The High Level alarm float must be
above the Pump ON float but below any inlets. No float should be
set above the inlet to the basin.
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.
Figure 1 shows a typical installation. Variations may apply to
actual installation.
Figure 1. Typical Indoor Installation (Pro380-Series shown)
Table 1. Float Switch Settings
System
Float
Levels
Piggyback Switch
(1-Float System,
Wide-Angle)
Pump OFF
Factory set.
3-1/2” float tether.
Pump ON
Factory set.
3-1/2” float tether.
Piggyback Switch
(1-Float System,
Vertical)
Pump OFF
Factory set.
2” from bottom of
float rod.
Pump ON
Maximum travel on
float rod.
Simplex Pump
Station
(3-Float System)
Pump OFF
Level to top of motor
housing.
Pump ON
Minimum 1-1/2’ above
Pump OFF level.
High Level
Minimum 1’ above
Pump ON level and
below inlet pipe. Below
influent pipe.
Duplex Pump
Station
(4-Float System)
Pump OFF
Level to top of motor
housing.
Lead Pump ON
Minimum 1-1/2’ above
Pump OFF level.
Lag Pump ON
Minimum 1’ above
Lead Pump ON level.
High Level
Minimum 1’ above Lag
Pump ON level and
below inlet pipe. Below
influent pipe.
RISK OF ELECTRIC SHOCK
Alarm
(optional)
Vent
Union
Check Valve
Ball Valve
Discharge
Use No-hub Style
Connector 4" Inlet Pipe
