©Copyright 2014 Liberty Pumps Inc. All rights reserved 6
2-4
DESIGN OF PUMP
Liberty LEH-Series Sewage pumps are designed to be operated continuously submerged underwater. The
motor and pump form a close coupled, watertight unit. The pump’s motor is insulated against heat and
moisture in accordance with Class B 130°C (265°F) regulations.
A thermal overload protector is imbedded in the motor windings of all single phase pumps. This is connected
in series and wired to shut down the pump if overheating occurs. The overload switch resets automatically
when the motor cools.
The motor is protected against damage from water entry by a double seal design. The lower seal is a lip seal,
composed of a rubber based elastomer. The upper seal is a mechanical cartridge seal, consisting of two
silicon-carbide faces. If the mechanical seal becomes compromised, pollution of the pumped liquid could
occur due to turbine oil seeping into the volute cavity.
The impeller and volute are designed for efficient flow characteristics and clog-free operation. The cast iron
impeller is designed to pass solids up to 5.08 cm (2”) in diameter. To avoid blockages, system discharge
piping must have an inner diameter no less than that of the maximum solid size, 5.08 cm (2”).
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LEH-E SERIES MODEL SPECIFICATIONS
All models, as designated in Table 1, require a separate approved pump
control device or panel for automatic operation. Operation of these
models will be according to the control selected. Make sure the
electrical specifications of the control selected properly match the
electrical specifications of the pump. 3 phase models require overload
elements selected or adjusted in accordance with the control or panel
instructions. Improperly set controls can cause the pump to not
operate as designed, causing pump damage and flooding.
TABLE 1: MODEL SPECIFICATIONS
Model
HP
Volts
50 Hz Phase
Full Load
Amps
Solids
Handling
FNPT
Discharge
Shut-off
Head (m)
Winding
Resistance
(Ω)
* LEH152MX-3E 1.5
230
1
11.1
2”
2” or 3”
13
1.5 – 2.5
* LEH153MX-3E 1.5
230
3
13.2
2”
2” or 3”
13
1.5 – 2.5
* LEH154MX-3E 1.5
400
3
4.9
2”
2” or 3”
13
6.5 - 7.5
* LEH202MX-3E
2
230
1
11.4
2”
2” or 3”
15
1.5 – 2.5
* LEH203MX-3E
2
230
3
13.2
2”
2” or 3”
15
1.5 – 2.5
* LEH204MX-3E
2
400
3
5.2
2”
2” or 3”
15
6.5 - 7.5
* X in model name designates discharge flange size and configuration
Rotating parts hazard. When pump is energized, be
careful around pump base. Pump should be in a basin or
a safe distance from people and objects, especially wires.
Energized pump may start without warning, for
example, when the pump cools after a thermal
overload. Never work on an energized pump.
