SPDT Flow Switch NEMA 3R, SS PADDLE
The F61 Series Flow Switches respond to fluid flow in lines carrying water, ethylene glycol, or other nonhazardous fluids. Two subseries are available. F61 Series Sensitive Flow Switches respond to low fluid flow rates in applications with pipe sizes under 1-inch trade size. F61 Series Standard Flow Switches use a variety of paddle sizes to respond to fluid flow rates in applications with pipe sizes greater than 1-inch trade size.Features and Benefits
❑ NEMA 3 or NEMA 3R Enclosure on Selected Models Allows use in indoor or outdoor applications
❑ Stainless Steel Bellows on Selected Models Allow use in fluid lines carrying chlorinated water, treated water, or other nonhazardous fluids
❑ Low-Flow Operation on Selected (Sensitive) Models Actuates switch with less than 1.0 GPM (3.8 L/min) flow for water applications or 9.0 GPM (34.1 L/min) flow for steam applications
❑ Gold-Plated Contacts on MG Models Reduces intermittent contact problems in low-voltage and low-current circuits
❑ Maximum Fluid Pressure of 150 psig (1034 kPa) Permits use in a wide range of pressure flow conditions
IMPORTANT: All F61 Series Flow Switches are
intended to control equipment under normal
operating conditions. Where failure or malfunction of
an F61 Flow Switch could lead to an abnormal
operating condition that could cause personal injury
or damage to the equipment or other property, other
devices (limit or safety controls) or systems (alarm or
supervisory) intended to warn of, or protect against,
failure or malfunction of the F61 Flow Switch must
be incorporated into and maintained as part of the
! CAUTION: Risk of Equipment Damage.
Do not use F61 Series Flow Switches with
hazardous fluids or in hazardous atmospheres. Use
in these conditions may cause malfunction or
IMPORTANT: F61 Series Flow Switches must not
be used where the fluid in the pipes drops below the
fluid’s freezing point, causing an internal freeze-up.
Sensitive Flow Switches
The F61 Series Sensitive Flow Switches have 1/2 in. Female NPTF or 3/4 in. Female NPTF inlet and outlet connections.
Use F61 Sensitive Flow Switches in applications where flow rates are low, such as:
• water purification and treatment systems
• booster pumps
• cooling systems for electronic tubes, bearings, and compressors
• rapid recovery water heaters (starting the water heater when water is withdrawn)
• control of food waste disposal units (starting motor when a predetermined amount of water is flowing through the unit and stops when the flow decreases to a predetermined rate)
• switch to shut down the refrigeration compressor on a fluid chiller system if flow stops, reducing chances of chiller freeze-ups
Standard Flow Switches
Use F61 Series Standard Flow Switches in applications with fluid pressures up to 150 psig (1034 kPa). A typical application for a standard F61 flow switch is to shut down the refrigeration compressor on a fluid chiller system if flow stops, reducing chances of chiller freeze-ups.
NEMA 1 Enclosures
Use models with NEMA 1 enclosures for indoor applications where they are protected from weather and splashing water. Use these models with pipes carrying fluids at temperatures in the range of 32 to 250°F (0 to 121°C) where fluid temperatures are above ambient dew point.
NEMA 3/NEMA 3R Enclosures
Use models with NEMA 3/NEMA 3R (rain-tight) enclosures for indoor or outdoor applications in high-humidity environments. Use these models in applications with pipes carrying fluids at temperatures below dew point temperature or below 32°F (0°C) but above -20°F (-29°C). Do not use these models in applications or environments where the temperature may cause the fluid to freeze.
Models with gold-plated contacts provide improved
electrical performance in low-voltage, low-current
circuits. Use these models for low-energy loads to
operate small relays, solenoid valves, and electronic
The flow switch responds to pressure exerted on the
fluid paddle by the flowing fluid. A range adjustment
screw adjusts the rate of flow required to actuate the
The red terminal or wire is the Common. The green
wire is Ground. Red to Yellow closes on flow increase.
Red to Blue closes on flow decrease.
F61 Series Sensitive Flow Switches do not require
adjustment or installation of paddles prior to mounting
the flow switch.
Some models of the F61 Series Standard Flow
Switches require installation or adjustment of paddles
prior to mounting. See Installing the Flow Paddles.
F61 Series Standard Flow Switches have a
three-piece flow paddle installed at the factory. Some
models also include a large flow paddle for large pipe
Replaces Part Numbers: F61LB-1