Description
McDonnell & Miller 120201 FS7-4W – 1¼" NPT NEMA 4X Industrial Liquid Flow Switch
Durable Flow Switch with Adjustable Sensitivity & Magnetic Switching
The McDonnell & Miller FS7-4W is a 1¼" NPT industrial liquid flow switch built for tough environments requiring water-tight and dust-tight protection with a NEMA 4X enclosure. Its rugged brass body and sealed tube construction ensure durability and long life in demanding HVAC, process, and commercial applications.
Featuring a magnetic switching mechanism and a single pole, double throw (SPDT) snap switch, the FS7-4W includes an adjustable sensitivity screw and paddles that can be trimmed to fit custom piping needs. It operates reliably over a wide temperature range and can handle pressures up to 300 PSI.
Key Benefits:
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NEMA 4X rated for corrosion and weather resistance
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Adjustable paddle lengths to suit specific applications
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Magnetic switch ensures precise, dependable operation
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Supports 120V and 240V systems with 7.4A/3.7A ratings
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Optional stainless steel body, paddles, extended paddle arms, and BSPT threads available
Applications:
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Industrial liquid flow monitoring
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HVAC system flow detection
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Process control and water treatment systems
Specifications
| Attribute | Details |
|---|---|
| Part Number | 120201 FS7-4W |
| Product Type | Industrial Liquid Flow Switch |
| Connection Size | 1¼" NPT Threaded |
| Switch Type | Single Pole Double Throw (SPDT) |
| Enclosure Rating | NEMA 4X |
| Amperage | 7.4A (240V), 3.7A (120V) |
| Voltage | 120V / 240V |
| Frequency | 50 / 60 Hz |
| Temperature Range | 32°F to 225°F (0°C to 107°C) standard; up to 300°F (149°C) max |
| Max Pressure | 300 PSI (21 kg/cm²) standard; 1000 PSI (70 kg/cm²) stainless steel option |
| Material | Brass (standard); stainless steel (optional) |
| Features | Adjustable paddle, magnetic switch, trim-to-fit paddles |
