WO / DO Mode — Must Be Specified at Order
Series 20 switches are available in Wet Open (WO) or Dry Open (DO) configuration. These are not NO/NC — the mode depends on float orientation and stem direction. You must specify WO or DO when ordering. See individual product pages for trip-point behavior details.
Products
Series 20 Product Line
20-611
Base Liquid Level Switch
Single-point top-mount level switch. Installs through 1/4 NPT bulkhead fitting with jam nut and O-ring seal. The foundation of the Series 20 system — used alone or combined with receptacle and adapter sets.
Mount
1/4 NPT · Bulkhead
Float Dia.
2" (50.9mm)
Total Length
3.8" (96.52mm)
Pressure
20 PSI @ 20°C
PP Polypropylene
AC Acetal
KR Kynar
20-613
LP2 Top Mount Receptacle Switch Set
Complete switch set with snap-and-screw receptacle for tool-free field disconnect. Includes 20-611 switch, adapter/seal set, spacer, and receptacle. 2" NPT top mount. Ideal where wiring access or periodic removal is required.
Mount
2" NPT · Top
Float Dia.
2" (50.9mm)
Total Length
4.63" (117.6mm)
Includes
Switch + Adapter + Receptacle
PP Polypropylene
AC Acetal
KR Kynar
20-614
Top Mount Low Profile Receptacle Switch Set
Rain-tight low profile receptacle set with rotating 1/4 NPT nipple for positioning flexibility. Self-sealing screw cap. Accommodates AWG 20 stranded wire splice. 20 PSI rated at 20°C — derates to zero at 90°C. 2 NPT top mount.
Mount
2 NPT · Top
Float Dia.
2" (50.9mm)
Total Length
4.63" (117.6mm)
Pressure
20 PSI @ 20°C
PP Polypropylene
AC Acetal
KR Kynar
20-202
2-Station High-Low Control Set
Two-switch high-low control set with 20A relay control head rated for motor control. Stem ships at 60" — customer cuts to length. Independently positionable high and low switch stations. Start high/stop low or vice versa.
Relay
20A Motor Control
Voltage
120V or 240V
Stem
60" cut-to-length
Stations
2 (High + Low)
PP Polypropylene
AC Acetal
KR Kynar
Components & Hardware
Build Custom Extended-Stem Level Control Systems
Every Series 20 part is sold individually. Combine a control head, stem set, floats, and hardware to build custom single-stem multi-level switch assemblies — from simple high-low pump control to multi-station alarm and shutdown systems. All components share standard interfaces and are available in PP, Acetal, and Kynar.
20-726
Stem + 1 Float Set
Stem assembly with one float station for single-point extended-stem level control. Mates with 20-725 control head. Available in 20", 40", and 60" lengths. Cut to length at installation.
Lengths
20" · 40" · 60"
Float Stations
1
PP
AC
KR
20-727
Stem + 2 Float Set
Stem assembly with two independently positionable float stations for dual-point level control. High-low, fill-drain, or alarm configurations. Mates with 20-725 control head. Available in 20", 40", and 60" lengths.
Lengths
20" · 40" · 60"
Float Stations
2 (Independent)
PP
AC
KR
20-725-120
Control Head — 120V
120V relay control head with factory-sealed 20A SPDT relay. Rain-tight O-ring sealed ABS enclosure. 1-1/4 NPT. 3/4 HP motor rated. Accepts 20-726/727 stem sets.
Voltage
120V AC · 3/4 HP
Relay
20A SPDT
20-725-240
Control Head — 240V
240V relay control head with factory-sealed 20A SPDT relay. Rain-tight O-ring sealed ABS enclosure. 1-1/4 NPT. 1-1/2 HP motor rated. For 240V single-phase circuits. Accepts 20-726/727 stem sets.
Voltage
240V AC · 1-1/2 HP
Relay
20A SPDT
Individual Parts
Replacement & Build-Your-Own Components
20-725-HS
Relay Housing Shell — 1-1/4 NPT, O-ring sealed, rain-tight ABS
From $27.69
20-719-NO
Switch Assembly — Bestact™ replacement element, normally open
From $30.93
20-720
Magnetic Float — 2.06" dia., 20 PSI max
From $12.38
PP · AC · KR
20-722
Stem Tube — 20", 40", 60", 100" lengths
From $10.20
PP · AC · KR
20-721
Collar Stop — float travel limiter for extended-stem assemblies
From $4.57
PP · AC · KR
20-723
Lead-In Bushing — stem-to-housing interface
From $1.73
PP · AC · KR
20-724
Retaining Ring — secures components on stem
From $1.73
PP · AC · KR
Specifications
Series 20 Electrical & Environmental Ratings
Electrical Ratings
Switch Element
Yaskawa Bestact™ R25
AC Rating
240V · Make 10A · Break 0.5A
DC Rating
115V · Break 0.3A
Inductive Load
120 VA · 240V AC
Mechanical Life
100K ops (AC) · 300K ops (DC)
UL Listing
Class 1, Div 2, Groups A–D
Application Environment
Max Pressure
20 PSI @ 20°C
Pressure Derating
Zero @ 90°C
Max Temperature
90°C
Min SG — PP
0.80 (clear liquid)
Min SG — AC
0.75 (clear liquid)
Min SG — KR
0.95 (clear liquid)
Float Buoyancy (SG 1.0)
PP — Exposed
1.0" (25.4mm)
PP — Submerged
1.05" (26.7mm)
AC — Exposed
0.65" (16.5mm)
AC — Submerged
1.40" (35.6mm)
KR — Exposed
0.30" (7.6mm)
KR — Submerged
1.75" (44.5mm)
Why Series 20
Built for Industrial Control — Assembled in Minutes
01
Inductive Load Switching
The Bestact™ element switches contactors and solenoid valves directly. No interposing relay required at the switch point.
02
Nothing Special Required
Set screws, O-ring seals, and jam-nut hardware are standard. Cut stem to length at the assembly sight. No custom tooling.
03
Spare Parts Are Meaningful
No other product in this class is designed for field disassembly. Swap the switch element in minutes. Repair costs are a fraction of replacement.
04
Common Part Set
All Series 20 products share a single system of complementary snap-and-screw components. One ecosystem covers single-point to multi-station control.
Applications
Where Series 20 Is Used
High-Low Pump Control
Solenoid Valve Control
Motor Control Circuits
Electroplating Systems
Semiconductor Processing
Diesel Day Tank Control