POTTER VSR-3.5

Product Overview

The VSR-3.5 is a highly dependable vane-type waterflow switch designed for use on wet sprinkler systems. Engineered for accuracy and long-term performance, it is certified by UL, cUL, CSFM, and FM, with the VSR-EU version available for CE and VdS compliance. Suitable for steel pipe ranging from 2" to 8" (schedules 10–40), this model detects water movement when a minimum flow of 10 GPM (38 LPM) occurs downstream.

Its design includes two SPDT snap-action switches, an instantly recycling pneumatic retard, and a rugged NEMA 4/IP54 enclosure, making it ideal for both indoor and outdoor environments. Built to operate under demanding conditions, the VSR-3.5 supports multiple NFPA applications, functions as a sectional flow detector on larger systems, and incorporates a factory-installed non-corrosive sleeve for added durability.

Key Features

• UL, CUL, CSFM Listed and FM Approved; VSR-EU available for EN12259-5 / VdS requirements
• Vane-type waterflow detector for wet sprinkler systems
• Compatible with 2"–8" steel pipe (Schedules 10–40)
• Flow activation at 10 GPM (38 LPM) or more
• Includes two SPDT (Form C) switches with the following ratings:
  • 10 A at 125/250 VAC
  • 2 A at 30 VDC (resistive)
  • 10 mA minimum at 24 VDC
     
• Adjustable pneumatic retard for accurate flow confirmation
• Maximum service pressure of 450 PSI (31 BAR)
• Flow sensitivity range: 4–10 GPM (15–38 LPM)
• Maximum allowable surge: 18 FPS (5.5 m/s)
• Enclosure rated NEMA 4/IP54, suitable for indoor or outdoor use
• Operating temperature range: 40°F to 120°F (4.5°C to 49°C)
• Two 1/2" conduit knockouts; isolated switch compartments for different voltages
• Factory-installed non-corrosive sleeve
• Applicable for NFPA-13, NFPA-13D, NFPA-13R, and NFPA-72 systems