Red Jacket LPG Premier, Installation Manual, Page: 25 / 40

Installing A Red Jacket Submersible LPG Pump-Motor Unit Fitting the Pump-Motor Unit into the Manifold or Storage Tank
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Fitting the Pump-Motor Unit into the Manifold or Storage Tank
The pump-motor unit should be carefully lifted by suitable means that will provide control and stability while
lowering the unit through the opening.
Electrical Connection
The electrical path must include a vapor sealing device, such as a compound sealing Y-fitting or EEx cable entry
between the pump and junction box as per local code regulations.
1. Disconnect, lock out, and tag the power before starting to service the pump.
2. Connect the three-phase power supply from the master panel to terminals L1, L2, and L3 in the magnetic
starter.
3. Before running the pump, the tank and pump well must contain LPG and be purged of air following
recommended procedures contained in this manual and per local regulations.
Determining Correct Motor Rotation
Where it is not convenient to predetermine the power supply phase sequence, proper rotation can be determined
by pump performance. Pump head pressure and capacity will be considerably less than rated when the pump is
rotating backwards.
Using coded wires, connect a wire from terminal T1 in the magnetic starter to a pump wire in the junction box of
the appropriate submerged pump. Connect another wire from starter terminal T2 to another pump wire and a third
wire from T3 to the last pump wire.
With ample LPG in the tank and pump well, start the pump and take a pressure gauge reading of the pump
pressure with the ball valve closed.
Next, reverse power leads at magnetic starter. Repeat pressure test, as described above. If results are higher than
the first test, the rotation during the second test is correct. If the second test gives lower results than the first,
reconnect the power leads as they were initially (as under test 1) for correct rotation.
Where the power supply has been properly marked L1, L2, and L3 in accordance with accepted phase rotation
standards, it is possible to predetermine the proper rotation of these units. The pump power leads are color coded
orange, black, and red, and if connected through the magnetic starter to L1, L2, and L3 respectively, the motor will
rotate in the correct direction. It is recommended, however, that the performance tests always be made whether or
not the power supply has been properly ‘phased out’.
Three-Phase Current Unbalance
Three-phase current unbalance is a factor that can result in premature motor failure. It causes reduced starting
torque, excessive and uneven heating and excessive motor vibration. Therefore, it is important that the electrical
load to the submersible motor be balanced. After the correct motor rotation is established, the amount of current
unbalance among the three legs of the power supply should be calculated.
To prevent changing motor rotation when taking these readings, the wires to the pump should be moved across
the starter terminals by always moving them in the same direction.
Percentage unbalanced = maximum current difference from average current divided by average current times 100.
As seen in the example in Figure 6, the third connection has the lowest percentage of unbalance and should be
used to obtain maximum motor efficiency and reliability.
OFF