Potter VSR-4 VSR Series Vane Type Waterflow Alarm Switch with Retard, 4" Nominal Pipe Size

Protect your facility with dependable sprinkler monitoring — the Potter VSR-4 vane type waterflow alarm switch by Potter Electric Signal is engineered for reliable detection and false-alarm reduction on wet sprinkler systems. The VSR-4 is UL Listed and FM Approved for common steel pipe schedules and fits a 4" nominal pipe size, providing proven compatibility for 2"–8" installations. Its vane-actuated design senses flows at the industry threshold (typically 10 GPM or within the UL sensitivity range of 4–10 GPM), and an adjustable, instantly recycling pneumatic retard lets you tune delay times to prevent nuisance trips while ensuring true events are reported.

Built for integrators and service professionals, the VSR-4 includes two SPDT (form C) switches in separate compartments for dissimilar voltages, convenient 1/2" conduit knockouts, and a tamper-resistant die-cast enclosure. Use it as a sectional detector on large systems or as the primary waterflow switch for fire alarm and security monitoring applications. Specify the Potter VSR-4 for improved fire protection, surveillance integration, and reliable monitoring — contact your distributor to order or to discuss system integration.

• Reliable, fast detection of sprinkler waterflow to minimize response time and protect assets
• Adjustable pneumatic retard reduces nuisance alarms while ensuring genuine flows (adjustable delay)
• UL/FM/LPCB listings and 4" nominal pipe size compatibility for easy integration into compliant wet sprinkler systems
• Dual SPDT contacts and separate conduit knockouts support independent monitoring and connection to fire panels or building management systems
• Tamper-resistant die-cast housing with optional cover tamper switch enhances system security and prevents unauthorized access