The Model VSR-FEX is a vane type waterflow switch for use on wet sprinkler systems located in hazardous locations. The unit may also be used as a sectional waterflow detector on large systems.

The unit contains two single pole, double throw, snap action switches and an adjustable, instantly recycling pneumatic retard. The switches are actuated when a flow of 10 gallons per minute (38 Lpm) or more occurs downstream of the device. The flow condition must exist for a period of time necessary to overcome the selected retard period.

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Waterflow Alarm Vane Switches For Use In Hazardous Locations: UL Listed/FM Approved waterflow alarm switches shall be furnished and installed at each sprinkler system connection to the wet pipe main where indicated on the drawings, and as required by NFPA Standards. Waterflow switches shall be capable of operation in system pres¬sures up to 450 PSI, maximum surges of up to 18 FPS and alarm activation at 10 GPM. Switch configuration shall consist of two sets of single pole double throw (S.P.D.T.) Form C synchronized sets of contacts rated at 15A, 125VAC and 2A, 24VDC. Switch enclosure shall be suitable for use in Class I: Groups C, D, Division 1 and two; Class II: Groups E, F, G, Division 1; Class III: Division 1 and two and shall be equipped with an instantly recycling adjustable retard with a 0-90 second range. Enclosure cover shall be held captive by tamper resistant screws or supervised for removal by a cover tamper switch. Flow switch saddles shall be corrosion resistant by means of a factory installed non-corrosive insert. Waterflow alarm vane switch shall be Model VSR-FEX manufactured by Potter Electric Signal Company.

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