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page 12 — st4/st6 series submersible pumps • operation anD parts manual — rev. #1 (11/12/13)
floaT swiTChes
mechanical Float switch
Mechanically activated float switches offer a reliable low
current control for dewatering applications.
How it Works
The mechanical float switch control will turn
on
(close)
when the float tips 45° above -horizontal, indicating a high
level, and turns
oFF
(opens) when the float switch drops
45° below horizontal. Reference Figure 4 and Figure 5.
Maximum pumping range is 120 degrees. See Figure 3
below.
Figure 3. Pumping Range (Float Switch)
pumping range
The pumping range of the pump is determined by the float
switch tether cord. Use Table 3 as guide line to determine
your required pumping range. Pumping ranges are based
on non-turbulent conditions. Range may vary due to water
temperature and cord shape. Please note as the tether
length increases, so does the variance of the pumping
range.
PUMP
ON
60
60
120
PUMP
OFF
table 3. pumping range
tether length
2 in.
5.08 cm.
4 in.
10.16 cm.
6 in.
15.24 cm.
8 in.
20.32 cm.
10 in.
25.4 cm.
12 in.
30.48 cm.
14 in.
35.56 cm.
16 in.
40.46 cm.
pumping range
6 in.
15.24 cm.
10 in.
25.4 cm.
14 in.
35.56 cm.
18 in.
45.72 cm.
22 in.
55.88 cm.
27 in.
68.58 cm.
31 in.
78.74 cm.
35 in.
88.9 cm.
Design Features
Float switch housings are constructed of high-impact,
corrosion resistant polypropylene with mechanically
activated, snap action contacts.
Suitable for most liquid environments.
Hermetically sealed.
Thick-walled non-corrosive PVC plastic enclosure.
Pressure tested to 30 ft. (9 meters).
Standard SJO, 16-gauge, 2 conductor cord (20 ft./6.09 m).
Figure 4. Float Switch (Closed)
Figure 5. Float Switch (Open)
ON/OFF
RAMP
STEEL
BALL
CONTACTS
CLOSED
ON/OFF
RAMP
STEEL
BALL
CONTACTS
OPEN
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