The Potter PS15 Series Supervisory Pressure Actuated Switches are designed primarily to detect an increase and/or decrease from normal system pressure in automatic fire sprinkler systems. Typical applications are: air/nitrogen supervision in Dry pipe and pre-action systems, pressure tanks, air supplies, and water supplies. The PS15 has two switches. The Low switch is factory set to activate at approximately 10 psi (0,35 BAR) on a decrease in pressure. The High switch is factory set to activate at approximately 20 psi (1,4 BAR) on an increase in pressure. See section heading Adjustments and Testing if other than factory set point is required.

The Potter PS25 Series Supervisory Pressure Actuated Switches are designed primarily to detect an increase and/or decrease from normal system pressure in automatic fire sprinkler systems. Typical applications are: air/nitrogen supervision in dry pipe and pre-action systems, pressure tanks, air supplies, and water supplies. The PS25-2 has two switches. The Low switch is factory set to activate at approximately 18 psi (1,2 BAR) on a decrease in pressure. The High switch is factory set to activate at approximately 28 psi (1,9 BAR) on an increase in pressure. NFPA 72 requires a supervisory signal for both high and low pressure conditions. The PS25 is factory set for a normal air pressure of 23 psi. See section heading Adjustments and Testing if other than factory set point is required.

Unique Features

  • Each devlce has two independent pressure chambers and independently adjustable switches
  • 300 psi pressure rating
  • Separate wiring chambers for low and high voltage to comply with NEC 760 without special wiring or coordination between trades
  • PS15-2 is Factory set for nominal system pressure of 15 psi. Low switch activates at 10 psi, High switch activates at 20 psi
  • PS25-2 is Factory set for nominal system pressure of 25 psi. Low switch activates at 18 psi, High switch activates at 28 psi 

Codes and Approvals

  • UL, cUL, CSFM, FM LPCB, NYMEA, CE
  • NFPA 72, 2016,  17.16.2
  • NEC 760

Engineering Specifications

Pressure Supervisory Switch for Low Differential Dry Pipe and Preaction systems
UL, CUL Listed / FM, LPCB Approved and CE Marked pressure supervisory switches shall be furnished and installed at the system pressure connection of each dry pipe valve and preaction system and where indicated on the drawings and plans and as required by applicable local and national codes and standards. Connection to the system shall be via a ½” bleeder valve installed between the pressure supervisory switch and the pressure source to permit testing.  Pressure supervisory switches shall be diaphragm type devices consisting of a non-corrosive ½” NPT male nipple for connection to the sprinkler system, dual non-corrosive pressure chambers and diaphragms, independently adjustable pressure settings, two conduit entrances and two Single Pole Double Throw (SPDT) switches separated by a barrier providing separate wiring chambers for each switch to comply with the NEC requirements for separation of power limited and non power limited conductors without the need for special wire or wire methods. The device shall be NEMA 4 rated and the enclosure shall be held captive by a tamper resistant screw. It shall be possible to install an optional cover tamper switch to detect removal of the enclosure. It shall be possible to change the factory set operating point of the pressure switch without the use of any tools. It shall be possible to change the pressure setting of either switch without affecting the pressure setting of the other switch. There shall be two models; PS15-2 and PS25-2 for valves and/or system requiring different pressure ranges. The PS15-2 shall be factory set at 10 psi for low pressure and 20 psi for high pressure and shall have an adjustable range of 5-30 psi.  The PS25-2 shall be factory set at 18 psi for low pressure and 28 psi for high pressure. The adjustable range shall be 10-60 psi. The devices shall be listed for pressures up to 300 psi. The switch contacts shall be rated at 10.1A, 125VAC and 2A, 30VDC.  Bleeder valve shall be model BVL manufactured by Potter Electric Signal Company LLC.

Other Information for Engineers

  • The separate wiring chambers allow for NEC compliance of low and high voltage wiring without special wire or coordination between trades. This saves installation time and eliminates any problems or questions during final inspection
  • The 300 psi rating allows them to be used on high pressure systems such as in high rises
  • The PS15-2 was specifically developed for low differential dry valves

Installation Tips

  • The pressure connection should always point down towards the floor to reduce the possibility of debris clogging the line
  • Use Teflon tape on the pressure connection. Do not use pipe dope as it could clog the pressure chamber
  • Tighten the device using the wrench flats on the pressure connection. Do not tighten by twisting the base or cover

Tech Tips

  • The LOW and HIGH markings just identify which switch was factory set. Each switch can be independently set to trip on a pressure increase or decrease

Other Information

  • If there is a shut off valve that is installed in-line with the PS10, it shall be supervised in accordance wit5h NFPA 13 and 72. The Potter RBVS is used to supervise 1/4 turn ball valves
  • A bleeder valve should always be installed in line with any low pressure switch on dry pipe or preaction system to facilitate testing. It saves time and money and will eliminate any possibility of accidently tripping a dry pipe valve.
  • The use of a bleeder valve is especially important when using nitrogen as it helps to conserve nitrogen and reduce wear on the generator

Click here to view more info about the PS15

Click here to view more info about the PS25

For additional questions, contact customer service: sales@pottersignal.com, or tech support: tech@pottersignal.com


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