Supported Applications
The Omega 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, the bi-directional switch activates an electrical contact if the air flow of the fan falls below 8.2 ft/s (2.5 m/s), thus either turning the signaling device on or off.
Operating Conditions & Performance
The series operates within an ambient temperature range of -20 to 50°C (-4 to 122°F) and is rated for storage temperatures from -20 to 80°C (-4 to 176°F). The device features a switching threshold of air flow speed greater than 8.2 ft/s (2.5 m/s) with a fixed hysteresis of 3.3 ft/s (1 m/s). Electrical performance includes a contact resistance incl. wire of 370 mΩ and a service life exceeding 100,000 cycles.
Maximum switching capacity is rated at 10 W for resistive loads. Maximum switching voltage limits are NC, AC/DC 240 V; NO, DC 60V. Maximum switching current limits are NC, DC 500 mA; NO, DC 170 mA.
Key Specifications
• Contact Type: Reed/magnet contact
• Housing Material: Plastic, black
• Enclosure Rating: NEMA 1 (IP 20)
• Dimensions Overall: 34 x 17.5 x 7.5 mm (1.3 x 0.7 x 0.3")
• Electrical Connection: 2 x single strand AWG 26, length 500 mm (20"), tip of stranded wire stripped/tinned 5 mm (0.20")
Configuration Options
The FSW800B Series is available in configurations defined by contact logic and mounting hardware, including integrated protective grills for specific fan sizes.
• Contact Logic: Models are offered with NC (Normally Closed) contacts that open with air flow or NO (Normally Open) contacts that close with air flow.
• Mounting Options: Variants include an attachment clamp and/or clip, or integration into a protective grill.
• Finger Guard Sizes: Protective grills are available in 80 x 80 mm (3.15") and 120 x 120 mm (4.72") dimensions to match fan housings.
Key Product Differences
The series consists of six distinct model numbers differentiated by contact state and the presence or size of a finger guard:
• FSW801B / FSW802B: Air-flow switch/monitor with mounting clip and clamp. FSW801B is NC; FSW802B is NO.
• FSW803B / FSW804B: Air-flow monitor with 80 x 80 mm (3.15") finger guard. FSW803B is NC; FSW804B is NO.
• FSW807B / FSW808B: Air-flow monitor with 120 x 120 mm (4.72") finger guard. FSW807B is NC; FSW808B is NO.
| Cable Diameter | 0.2 in |
| Cable Length | 20 in |
| Contact Resistance | 370 mΩ |
| Enclosure Ratings | IP20, NEMA Type 1 |
| Height | 1.3 in |
| Hysteresis | 3.3 ft/s fixed |
| Length | 0.3 in |
| Linear Flow Rate, Min | 8.2 ft/s |
| Materials | Plastic |
| Mounting Orientation | Air-flow monitor opening perpendicular to air flow |
| Operating Temperature, Max | 50 °C |
| Operating Temperature, Min | -20 °C |
| Process Temperature, Max | 80 °C |
| Process Temperature, Min | -20 °C |
| Series ID | FSW800B-Series |
| Width | 0.7 in |
| Wire Gauge | 26 AWG |