Liberty Pumps 331 - Manual (Page 3)

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Brass male hose to male pipe
Prime plug – add water here prior to pump
operation.
Brass female hose
Suction hose (not included) - should not be
longer than needed (15’ maximum suction
lift). Use a high quality hose to prevent
collapsing.
Plastic male hose strainer
Motor
Brush
Brush
Access
Cap
Adapters are furnished with the pump. The inlet and discharge are threaded with a ¾” NPT. Standard water pipe can be threaded
directly into the casting. If a garden or other hose is to be used, the brass fittings must be installed. It is recommended that plumbing
tape or a pipe thread sealant when using the brass fittings. Liberty Pumps recommends that the swivel fitting be installed on the front of
the pump. NOTE: to reduce the possibility of hose collapse, use a high quality hose on the suction line (an ordinary garden hose may
collapse under suction pressure and should not be used).
Fig. 2
A strainer is furnished and should be used if pumping from a creek, pond, or source where foreign objects may be sucked into the
pump. The strainer helps prevent solids from entering the inlet line. This pump must be filled with water before operating.
Running the pump dry will cause damage to the shaft seal. This unit is not waterproof or weatherproof and should not be used in
showers, saunas, or other potentially wet locations. The motor is designed for use in a clean, dry location. The unit draws fresh air in
from the back and blows warm air out the sides, do not block air vents. Ambient temperatures around the motor should not exceed
104°F (40°C) in order to adequately cool motor. The motor is equipped with a thermal protector. If the motor temperature rises, the unit
will automatically turn-off. To reset the thermal switch simply unplug the unit or turn the electrical switch from on to off and allow unit to
cool. The switch must be in the off position in order for it to cool down. Please note that the water temperature should not exceed 140°
F.
1. IMPORTANT: Pump must be primed before operating to prevent shaft seal failure. To do this, remove the prime plug
(see Fig. 2) & fill the housing with water (approx. 2 cups). Replace the prime plug (hand-tighten only).
2. Connect garden hoses, making sure each connection is tight. A pin hole leak in the suction hose will prevent the unit from priming.
If using a garden hose, be sure to use a new rubber gasket.
3. Plug the power cord into a properly fused and grounded GFCI electrical outlet. Turn the power switch to the “on” position. The
amount of time it takes the pump to prime depends on the suction line length and height. A maximum vertical suction lift of 15 feet
through a ¾” diameter garden hose could take up to 2 minutes to prime.
4. A check valve installed near the bottom of the suction hose (not included) is recommended for suction lifts of more than 10 feet
(this reduces the amount of time required to draw water).
5. Please note that this pump retains water after use. In areas that are prone to freezing temperatures, please
be sure to drain the pump before storing it.
6. When used to transfer materials other than clear water (such as glycol), the pump must be flushed with
water and drained before storage to prevent potential pump damage. Some chemicals used in hydronic
systems can result in corrosion of the aluminum pump housing.
The Model 331 operates with a brush-type motor. To remove brushes for replacement or
cleaning, disconnect the power cord from electrical supply. Remove the brush caps by
turning them with a screwdriver counterclockwise. The brushes are attached to coil
springs, which pull outward from the pump. If used brushes are to be reinserted, mark the
location of each brush (left or right) and reinstall on the same side, in the same orientation.
Brush replacement should be scheduled after approximately every 300 hours of use.
3. Installation
4. Operation
5. Maintenance and Troubleshooting