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Brass flow switch with NPT threads, compact rectangular body

ITT McDonnell Miller

ITT McDonnell Miller FS5-1 1" FNPT SPDT Snap Flow Switch 120/240VAC 15 gpm

SKU CH-9GBB-1AWWW

1" NPT brass flow switch activates at 1.5 gpm, rated 22.2 A locked rotor at 240 VAC, operates 32 to 250 °F

  • Type1/3 HP, General Purpose, Electrically Operated
  • Length6.400
  • Weight2.5
  • SPDT snap action gives reliable flow detection
  • 1 in FNPT brass housing fits standard piping
  • Operates from 32 °F to 250 °F ambient and media
  • Rated 7.4 A @ 120 VAC and 3.7 A @ 240 VAC full load
  • 5 gpm set point with 5.1 in overall height

FS5-1 Snap Flow Switch for 1-Inch Pipe

The ITT McDonnell Miller FS5-1 is a brass-body snap flow switch designed for 1-inch NPT piping. It provides SPDT contact operation for general-purpose electrically operated control circuits. The unit is rated for ambient and media temperatures between 32 and 250 degrees Fahrenheit. It suits hydronic heating, cooling, and industrial process applications requiring flow verification.

Installation uses standard 1-inch FNPT threading

The switch threads directly into a 1-inch NPT pipe fitting with an overall height of 5.1 inches. Brass housing allows standard pipe sealant or tape without special tools. The fixed flow actuation point is set at 1.5 gpm; systems with variable or lower flow rates will not trigger the switch reliably. Electrical connections accept standard spade or screw terminals for 120 or 240 VAC supply.

SPDT contacts rated 22.2 A locked rotor at 240 VAC

The single specification that determines fit is the contact rating: 22.2 amps at 240 VAC locked rotor and 3.7 amps full load, with 44.4 amps locked rotor and 7.4 amps full load at 120 VAC. This rating must exceed the connected load inrush and steady-state current. Buyers controlling loads above these limits must select a different switch or add an intermediate relay.

Highlights

  • SPDT snap action gives reliable flow detection
  • 1 in FNPT brass housing fits standard piping
  • Operates from 32 °F to 250 °F ambient and media
  • Rated 7.4 A @ 120 VAC and 3.7 A @ 240 VAC full load
  • 5 gpm set point with 5.1 in overall height

Specifications

BrandMcdonnell & Miller
ModelFS5-1
Type1/3 HP, General Purpose, Electrically Operated
Length6.400
Weight2.5

Questions about this item

How do I verify the FS5-1 flow switch is operating correctly after installation?

Confirm the switch actuates at the 1.5 gpm flow rate and the SPDT contacts change state; the brass housing and 1" NPT connection should show no leaks at up to 250 °F media temperature.

What components are included with the FS5-1 and what must be purchased separately?

The flow switch unit with 1" FNPT brass housing is supplied; pipe fittings, wiring, and any required mounting hardware are not included and must be sourced separately.

Which flow-rate version of the FS5-1 should I select for my application?

The FS5-1 is offered with a fixed 1.5 gpm actuation point; choose this model when your system requires switching at that specific flow rate.

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