Multiquip Dual Mechanical Float Switch | 120V | High-Impact Polypropylene | Holding Relay | NEMA 5-15 Piggy-Back Plug | Adjustable 3–48 in. Range | 20 ft. Cord | SW2A

Multiquip SW2A Double Float Switch

The Multiquip SW2A is a double mechanical float switch designed to provide automatic ON/OFF control for compatible single-phase submersible pumps. It uses two mechanically activated wide-angle floats connected through a splice tube containing a holding relay. This arrangement provides accurate water-level control while helping prevent pump chatter in turbulent water.

Designed for demanding dewatering applications, the SW2A operates on 120/230V single-phase systems and uses corrosion-resistant, high-impact polypropylene float housings with heavy-duty electrical contacts. Its adjustable 3- to 48-inch operating range makes it suitable for applications where a controlled pumping range is preferred over a single-float arrangement.

Product Features:

• Dual-float automatic control: Uses two mechanically activated wide-angle floats to automatically control compatible submersible pumps.
• Holding relay: The splice tube contains a holding relay that allows the two floats to operate in series and helps prevent pump chatter in turbulent water.
• 3–48 inch adjustable range: Provides a broad adjustable pumping range for different basin, pit, and dewatering requirements.
• 120/230V operation: Designed for 120/230V, 50/60 Hz, single-phase applications within its electrical rating.
• 13A running rating: Rated for up to 13 amps of running current and 78 amps of startup current.
• High-impact polypropylene housing: Corrosion-resistant PP float housings are designed for demanding water-service applications.
• Heavy-duty contacts: Electrical contacts are designed for repeated automatic pump switching.
• Water-resistant float cables: Each float uses a 16-gauge, 2-conductor water-resistant cable.
• 20-foot piggy-back cable: The cable above the splice uses 14-gauge, 3-conductor construction and terminates in a 120V piggy-back plug.
• UL and CSA certified: The SW2A is UL listed and CSA certified for its intended electrical application.

What Is a Double Float Switch?

A double float switch uses separate ON and OFF float positions to control a pump over a defined water-level range. As the water rises to the activation point, the upper float initiates pump operation. As the water level falls to the deactivation point, the lower float stops the pump.

This arrangement creates a larger differential between pump start and stop levels than a simple single-float arrangement. The SW2A's holding relay also helps maintain the switching state in turbulent water, reducing unnecessary pump cycling and chatter.

Holding Relay and Pump Control

The SW2A's splice tube contains a holding relay that allows the two mechanical floats to function together in series. Once the pump is activated, the relay maintains the operating circuit until the water falls to the deactivation point. This design is particularly useful where water movement could otherwise cause a float to repeatedly switch the pump on and off.

Adjustable Pumping Range

Current 2026 Multiquip documentation specifies an adjustable range of approximately 3 to 48 inches. The float mounting position and tether length determine the actual operating range for the installation.

Multiquip describes the standard operating relationship as approximately 4 inches below the mounting point for deactivation and 4 inches above the mounting point for activation. The final operating levels depend on the installation configuration and tether arrangement.

Float Construction

Each float housing is constructed from high-impact polypropylene with corrosion-resistant properties. The wide-angle mechanical design allows the floats to respond to changing water levels without depending on electronic sensing components.

Heavy-duty electrical contacts are used for repeated switching, while the individual float cables use water-resistant 16-gauge, 2-conductor wiring.

Electrical Connection

The SW2A is rated for 120/230V, 50/60 Hz, single-phase applications. The assembly is rated for 13 amps of running current and 78 amps of startup current. The upper cable section uses 14-gauge, 3-conductor wiring and includes a 120V piggy-back plug for compatible pump applications.

The electrical rating of the float switch should not be exceeded. The connected pump and installation should be selected according to the electrical requirements of the specific application.

Cable and Mounting

The SW2A includes standard mounting cable and pipe clamps for securing the float assembly to a compatible discharge hose or installation point. The float cables should be positioned so that they can move freely and cannot become trapped, pinched, or damaged during pump operation.

When mounting the switch to a discharge hose, Multiquip instructions caution against placing the float cable underneath the hose clamp and recommend avoiding excessive tightening that could damage the cable.

Operating Temperature

The latest 2026 Multiquip pump documentation specifies operation in water up to 104°F (40°C) for the SW2A. Applications exceeding the specified temperature range should not be used without appropriate manufacturer approval.

Compatible Pump Applications

Multiquip lists the SW2A as an optional double-float control accessory for compatible single-phase submersible pumps. Current Multiquip documentation identifies it alongside the SW1A and SW1WOPA float options on models such as the ST2038P, ST2037F, ST3020BCUL, and PX400.

SW2A Specifications

• Accessory Type: Double mechanical float switch
• Float Quantity: 2
• Activation Type: Mechanically activated, wide-angle
• Control Type: Automatic ON/OFF
• Holding Relay: Integrated in splice tube
• Voltage: 120/230V
• Frequency: 50/60 Hz
• Phase: Single-phase
• Running Current Rating: 13A
• Startup Current Rating: 78A
• Adjustable Range: 3–48 in. (7.6–122 cm)
• Float Housing: High-impact polypropylene (PP)
• Float Cable: 16-gauge, 2-conductor, water-resistant
• Cable Above Splice: 14-gauge, 3-conductor
• Cable Length: 20 ft. (6.1 m)
• Plug: 120V piggy-back plug, NEMA 5-15 configuration
• Maximum Operating Water Temperature: 104°F (40°C)
• Electrical Contacts: Heavy-duty
• Certifications: UL Listed and CSA Certified
• NSF Testing: Passed NSF Standard 61 protocol
• Mounting Hardware: Standard mounting cable and pipe clamps included

SW2A vs. Single Float Control

The SW2A differs from the SW1A by using two floats and a holding relay rather than one float. The dual-float arrangement provides separate pump activation and deactivation points, creating a controlled pumping range and reducing unnecessary pump cycling in turbulent water.

Recommended Applications

The SW2A is well suited for unattended dewatering of pits, basins, tanks, construction sites, flooded areas, utility locations, and other applications where automatic pump operation and a controlled water-level range are required. Its dual-float configuration is particularly useful where turbulent water could cause excessive switching with a single float.

Why Choose the Multiquip SW2A Dual Float Switch?