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Compact Fan and Filter Fan Air Flow Switch

Compact Fan and Filter Fan Air Flow Monitor


Item# FSW801B

In stock

Lead Time (If not in stock): 10 weeks
Compact Fan and Filter Fan Air Flow Monitor FSW801B FSW801B
  • Reliable Mechanical Switch Contact
  • Small Size
  • Economical
  • Easily Installs Via Clip or Clamp

FSW801B Model Options

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Switch Rating and Type
Media Type
Velocity Range
Max Process Temperature
Wetted Materials
Wire Length

  • Contact Blocks Reed/magnet contact
  • Maximum Operating Temperature 50 {C} (122 {F})
  • Maximum Switching Current NC (DC 500 mA)
  • Maximum Switching Voltage NC (AC/DC 240 V)
  • Minimum Operating Temperature -20 {C} (-4 {F})
  • Switch Operation NO or NC Relay Operation
The FSW800B Series air-flow monitor provides a simple but reliable alternative to indicate positive or negative air flow of fans. When properly installed and connected in series with an optical (i.e. LED) or audible signaling device, a bi-directional switch will activate an electrical contact if the air flow of the fan falls below 8.2 ft/s, thus either turning the signaling device on or off.

Contact Type: Reed/magnet contact
NC (Normally Closed): Contact open with air flow
NO (Normally Open): Contact closed with air flow
Switching Threshold of Air Flow Speed: >8.2 ft/s (2.5 m/s)
Hysteresis: 3.3 ft/s (1 m/s)—fixed
Contact Resistance Includes Wire: 370 mΩ
Service Life: >100,000 cycles
Max. Switching Capacity: 10 W (resistive load)
Max. Switching Voltage: NC (AC/DC 240 V); NO (DC 60 V)
Max. Switching Current: NC (DC 500 mA); NO (DC 170 mA)
Connection: 2 x single strand AWG 26, length 500 mm (20'), tip of stranded wire stripped/tinned 5 mm (0.20')
Mounting: Attachment clamp and/or clip, or integrated in protective grill
Housing: Plastic, black
Dimensions: 34 x 17.5 x 7.5 mm (1.3 x 0.7 x 0.3')
Mounting Position: Air-flow monitor opening perpendicular to air flow
Operating Temperature: -20 to 50°C (-4 to 122°F)
Storage Temperature: -20 to 80°C (-4 to 176°F)
Protection Type: NEMA 1 (IP 20)
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Does this switch operate when airflow exceeds the set value in either direction? Or is the van movement dependent on the direction of the airflow?

Asked by: sini
Thank you for your inquiry. This switch is bi-directional and will work in either direction.
Answered by: AS Engineer
Date published: 2022-06-06

What is the Flammability rating for this FSW804B?

Asked by: shan7
Thank you for your inquiry about the air flow switch. Unfortunately, it is not rated for hazardous applications.
Answered by: Application Engineer JC
Date published: 2022-06-06

Do you have a cad model (.stp or equivalent) available for the switch to help integrate into a system?

Asked by: engineerbob27
Thank you for your inquiry! Unfortunately, we do not have and 3D models available for these switches. The only available dimensions will be those listed in the data sheet.
Answered by: Application Engineer JM
Date published: 2022-06-06

Do you have a product similar to FSW802B but rated NEMA 3R or NEMA 4 for outdoor use?

Asked by: DDF1
Thank you for your inquiry on the flow switch. Unfortunately, we do not have another air flow switch that is rated as NEMA for outdoors.
Answered by: Application Engineer JC
Date published: 2022-08-01
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