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.