ST-3050D SUBMERSIBLE PUMP — APPLICATION (FLOAT SWITCHES)
Float Switch Theory
There is a tilt-sensitive mercury switch hermetically sealed within each float. As the liquid level (water) rises or falls, the float changes its angle until the mercury switch makes (close) or breaks (open) the circuit.
The length of cord between the float and point of attachment determines the amount of water to be pumped.
Contact Multiquip sales department to order float switches.
Float Switch (Dual)
Float switches (Figure 2) are used for the unattended operation of the submersible pump.The ST-3050D pump requires the use of a control box to perform this function. Shown in Figure 2 is an example of a dual float control switch application.
The Model ST-3050D submersible pump requires one each of the Model SW-1WOP float type mercury switches. These switches have a pumping range level between 5.5~18 feet (1.67~5.5 meters). All float switch connections are bare wire (no plug). The ST-3050D submersible pump must use the CB 200 Control Box when float switches are required for the job application. The MCP102/104 control boxes do not have float switch capability.
CONTROL
BOX
EXTERNAL 3-PHASE (230 OR 460 VOLT)
POWER SOURCE
CAUTION! 
HIGH
VOLTAGE!
| CIRCUIT |
| BREAKER |
L1 | RED |
| WHITE |
L2 | BLACK |
L3 | GREEN |
|
GROUND
3-INCH
DISCHARGE
HOSE
ROPECB200
OFF
MANUAL AUTO
AC
AC FLOAT POWER
POWER SWITCH TO
INPUT INPUTS PUMP
PUMP
ON
FLOAT
SWITCHES
PUMP
OFF
Figure 2. Dual Float Control Switch
ST-3050D — PARTS & OPERATION MANUAL — REV. 0 (11/18/02) — PAGE 11
