Description

McDonnell & Miller FS-251 is a universal mechanical liquid flow switch, designed for turning On or Off a wide variety of electrically-operated equipment (pumps, alarms, burners, etc.). Includes a set of (4) rigid stainless paddles for use with various diameter pipes (sizes 1″ through 8″). Integral screw for adjusting flow sensitivity. NEMA 1 enclosure for indoor use only. Standard 1″ male NPT threaded connection.

Cross-References:

McDonnell & Miller: FS4-3
Hydrolevel: FS200
Taco: IFS01/02/H1/H2

Features:

Includes (4): 1″, 2″, 3″, & 6″ rigid stainless steel paddles for fitting into pipes of different sizes
Starts or stops electrical equipment, such as pumps, alarms, motors, burners, and metering devices, when water flow is detected in a system
Replaces common flow switches from Johnson/Penn, Taco, Watts, Hydrolevel, and other manufacturers
Suitable for pipe sizes from 1″ to 8″
Adjustable flow senstitivity via internal screw
cULus listed

Technical Specifications:

Electrical Specs: SPDT (Relay Type), NEMA 1 Enclosure
Application: 1″ – 8″ pipe sizes
Flow Rates: Refer to image specs for minimum and maximum rates for 1″ – 8″ pipe sizes
Connection: 1″ NPT, Threaded
Max Flow Velocity: 10 ft/sec
Pilot Duty: 125 VA @ 120 or 240 VAC; 50/60 Cycles
Switch Rating: 7.4 FLA, 44.4 LRA @ 120 VAC; 3.7 FLA, 22.2 LRA @ 240 VAC
Max Pressure: 160 psi
Max Water Temperature: 250°F
Max Ambient Temperature: 120°F

Warranty:
1-year warranty from the date of installation; 2-year warranty from the date of manufacture