Product Description
Dual Float Switch Assembly for Reliable Pump Control in Tight and Turbulent Conditions
The SJE Rhombus Double FloatMaster™ is a dual float switch designed for direct pump control in confined spaces, small diameter pits, and turbulent wastewater environments. This piggyback float switch operates 120V and 240V pumps (up to 2 HP), delivering a consistent and adjustable pumping range from 3" to 48".
Unlike single float designs, this double float pump switch uses two mechanical floats to control pump start and stop levels more accurately. The result is stable operation, reduced pump cycling, and improved system reliability in demanding sump, sewage, and lift station applications.
This float switch assembly features a piggyback plug configuration, allowing you to control your pump directly without a separate control panel, ideal for both permanent installations and temporary setups.
Key Features of the Dual Float Switch Assembly
Dual Float Design for Accurate Control
Two floats work together to manage pump ON and OFF levels, improving performance in turbulent or narrow environments.
Direct Pump Control (Piggyback Float Switch)
Plug-and-play design allows direct connection to pumps without a control panel.
High Capacity Ratings
15 amps Full Load Amps (FLA)
90 amps Locked Rotor Amps (LRA)
Adjustable Pumping Range
Easily set your operating range from 3" to 48", with extended ranges available.
Reliable Operation in Turbulent Conditions
Not sensitive to rotation or turbulence, making it ideal for wastewater systems.
Durable Float Construction
Corrosion-resistant polypropylene housing rated for use up to 140°F (60°C).
Mounting Clamps Included
Allows secure and adjustable installation on discharge pipes.
UL and CSA Listed
Certified for safety and performance across North America.
5-Year Manufacturer Warranty
Long-term reliability backed by SJE Rhombus Controls & Alarms.
Why Use a Dual Float Switch Instead of a Single Float?
A dual float switch provides a more controlled and reliable way to manage pump operation compared to a single float.
Separates pump ON and OFF levels for better control
Helps prevent short cycling, reducing pump wear
Maintains consistent operation in turbulent wastewater
Improves pump lifespan and efficiency
Provides a more accurate and adjustable pumping range
This is especially important in sump pump systems, sewage systems, and lift stations, where water levels can fluctuate quickly.
How the Double Float Switch Works
This double float switch assembly consists of:
Top float → Activates the pump (turns ON)
Bottom float → Deactivates the pump (turns OFF)
Inside the system, a holding relay allows the floats to function in series, ensuring stable and reliable operation.
This design:
Eliminates pump chatter in turbulent conditions
Maintains consistent pump cycles
Allows precise control over liquid levels
The adjustable distance between the floats determines the pumping range, giving you flexibility based on tank depth and system requirements.
Piggyback Float Switch: Simple Direct Pump Control
The piggyback float switch design makes installation simple:
Plug the float switch into the power outlet
Plug the pump into the float switch
The switch controls the pump automatically
This setup allows:
No control panel required
Quick installation
Easy manual override (plug pump directly into outlet if needed)
Perfect for:
Temporary systems
Budget-conscious installations
Retrofit applications
Applications
This dual float pump switch is suitable for a wide range of applications:
Sump pump systems
Sewage and wastewater systems
Lift stations
Effluent systems
Confined tanks and pits
Residential, commercial, and municipal installations
It performs especially well in:
Turbulent conditions
Narrow or tight spaces
Systems requiring a wide pumping range
Dual Float Switch Options
The SJE Double FloatMaster is available in multiple configurations:
Pump Down (Normally Open) – for emptying tanks
Pump Up (Normally Closed) – for filling applications
Available with:
120V or 240V piggyback plug
Direct wiring (no plug)
Cable lengths: 15 ft, 20 ft, 30 ft (longer lengths available)
Technical Specifications
Specification
Details
Voltage
120V / 240V (50/60 Hz, single phase)
Max Run Current
15 amps
Max Start Current
90 amps
Pumping Range
3" to 48" (adjustable)
Float Material
Polypropylene (corrosion-resistant)
Max Temperature
140°F (60°C)
Cable (Float)
18 gauge, 2-conductor SJOW
Cable (Above Splice)
14 gauge, 3-conductor SJTW
Certifications
UL, CSA
Important Notes:
Must be used with pumps that provide integral thermal overload protection
Designed for horsepower (HP) rated loads only
Not suitable for low-current control (pilot duty) applications
Installation & Wiring Overview
Ensure power supply voltage matches switch rating (120V or 240V)
For piggyback setup: plug the switch into the outlet, plug the pump into the switch
For direct wiring: follow the appropriate wiring diagram and code requirements
Floats should be mounted properly for correct operation
For detailed wiring, refer to:
SJE Rhombus float switch wiring diagrams
Installation instructions provided with the product
Related Float Switches and Pump Control Solutions
SJE PumpMaster Plus Float Switch – A single float switch option for simpler pump control applications where a dual float switch is not required.
Float Switches & Accessories – Find cable weights, mounting brackets, and additional float switch options to customize your system.
Tank Alarm Systems – Monitor water levels and system performance with compatible alarm panels and accessories.
Order SJE Double Float® Master Pump Switch Piggyback from Cleanflow
Upgrade your system with a proven SJE Rhombus Double Float® Master Pump designed for reliable pump control in demanding environments.
Cleanflow supplies SJE Rhombus Controls & Alarms products across Canada and the USA, offering:
Competitive pricing
Fast and reliable shipping
Trusted industrial-grade products
Expert customer support
Order your double float switch today and get reliable pump control where it matters most.
Frequently Asked Questions
What is a double float switch?
A double float switch uses two floats to control pump ON and OFF levels separately, providing more accurate and stable pump operation.
How does a piggyback float switch work?
A piggyback float switch plugs into a power outlet, and the pump plugs into the switch. The switch controls power to the pump automatically.
Why use a dual float switch instead of a single float?
Dual float switches reduce pump cycling, improve control accuracy, and perform better in turbulent conditions.
What is pump up vs pump down?
Pump down: empties a tank (normally open)
Pump up: fills a tank (normally closed)
Can this float switch be used without a control panel?
Yes. The piggyback design allows direct pump control without a control panel.
What wiring diagram should I follow?
Follow the SJE Rhombus wiring diagram for your voltage (120V or 240V). Always ensure voltage compatibility before installation.
What size pumps can this double float switch control?
The SJE Double FloatMaster is designed to control pumps up to 15 FLA (Full Load Amps) and 90 LRA (Locked Rotor Amps) for both 120V and 240V systems. This makes it suitable for many residential and light commercial sump and sewage pump applications.
NOTE: This switch must be used with pumps that provide integral thermal overload protection.
A Pump Switch is designed for Horsepower (HP) rated loads and is not suitable for control (pilot duty) applications. It will fail prematurely when switching loads less than 1 Amp at 120 VAC. Select a float switch from our Control Switch offering for control applications.
Usually ships same or next day. 
