Potter PS10 Series Pressure Switch

Features

• One or two switch models available.
• Independent switch adjustment on two-switch models, no tools needed.
• Two 1/2" conduit/cable entrances.
• Separate isolated wiring chambers.
• Non-corrosive pressure connection.
• VdS version available.
• Non-Conductive enclosure.
• Available with Nylon or Brass pressure connection (Nylon connection shown).

Notice

This document contains important information on the installation and operation of PS10 pressure switches. Please read all instructions carefully before beginning installation. A copy of this document is required by NFPA 72 to be maintained on site.

Installation

The Potter PS10 Series Pressure Actuated Switches are designed for the detection of a waterflow condition in automatic fire sprinkler systems of particular designs such as wet pipe systems with alarm check valves, dry pipe, preaction, or deluge valves. The PS10 is also suitable to provide a low pressure supervisory signal; adjustable between 4 and 15 psi (0.27 and 1.03 bar).

Installation Steps:

1. Apply Teflon tape to the threaded male connection on the device. (Do not use pipe dope).
2. Device should be mounted in the upright position (threaded connection down).
3. Tighten the device using a wrench on the flats on the device.

Wiring Instructions

1. Remove the tamper-resistant screw with the special key provided.
2. Carefully place a screwdriver on the edge of the knockout and sharply apply a force sufficient to dislodge the knockout plug. (Refer to Figure 9 for visual).
3. Run wires through an approved conduit connector and affix the connector to the device. NEMA 4 rated conduit and fittings are required for outdoor use.
4. Connect the wires to the appropriate terminal connections for the service intended. (Refer to Figures 2, 4, 5, and 6). See Figure 7 for two-switch, one-conduit wiring.

Technical Specifications

*Specifications subject to change without notice.

Testing and Adjustment

Note: Testing the PS10 may activate other system-connected devices. The operation of the pressure alarm switch should be tested upon completion of installation and periodically thereafter in accordance with applicable NFPA codes and standards and/or the authority having jurisdiction. Manufacturer recommends quarterly testing or more frequently. No adjustment should be needed when used as a pressure-type waterflow indicator, as it is factory set to comply with UL and FM standards.

Wet System

Method 1: For use with a control unit with retard. Connect PS10 to the alarm port piping on the input side of the retard chamber and electrically connect to the control unit that provides retard for surges. Ensure no unsupervised shut-off valves are present between the alarm check valve and PS10.

Method 2: For local bell application or with a control that does not provide a retard feature. Install PS10 on the alarm outlet side of the retard chamber of the sprinkler system.

Testing: Accomplished by opening the inspector's end-of-line test valve. Allow time for system or control retard to compensate.

Note: Method 2 is not applicable for remote station service use if an unsupervised shut-off valve exists between the alarm check valve and PS10.

Wet System With Excess Pressure

Connect PS10 into alarm port piping extending from the alarm check valve. Retard provisions are not required. Ensure no unsupervised shut-off valves are present between the alarm check valve and PS10.

Testing: Accomplished by opening the water by-pass test valve or the inspector's end-of-line test valve. Allow time for excess pressure to bleed off when using the end-of-line test.

Dry System

Connect PS10 into alarm port piping that extends from the intermediate chamber of the alarm check valve. Install on the outlet side of the in-line check valve of the alarm port piping. Ensure no unsupervised shut-off valves are present between the alarm check valve and PS10.

Testing: Accomplished by opening the water by-pass test valve.

Note: The above tests may also activate any other circuit closer or water motor gongs present on the system.

Diagrams and Connections

Figure 1: Dimensions

Illustrates the physical dimensions of the PS10 pressure switch, including height, width, depth, and the 1/2" NPT male pressure connection. Key features like the adjustment knob are also indicated.

Figure 2: Switch Clamping Plate Terminal

Shows the terminal plate for wiring connections. It indicates "Incoming" and "Outgoing" terminals for wires, along with screw terminals and a ground screw. The diagram highlights the importance of severing single conductors for supervision.

Figure 3: Typical Sprinkler Applications

This figure presents schematic diagrams for three common fire sprinkler system types:

• Wet System with Excess Pressure: Shows the PS10 connected to the alarm port of a wet pipe system with an alarm check valve, bypass valve, and water motor gong.
• Wet System Without Excess Pressure: Similar to the above but includes a retard chamber in the system.
• Dry System: Depicts the PS10 connected to a dry pipe system, including a dry check valve, retard chamber, and water motor gong.

Caution: Closing any shut-off valves between the alarm check valve and the PS10 will render the PS10 inoperative. NFPA-72 requires such valves to be electrically supervised with a supervisory switch (e.g., Potter Model RBVS).

Figure 4: Low Pressure Signal Connection

Illustrates how to connect the PS10 to a fire alarm panel for low pressure supervision, typically using an End-of-Line Resistor (EOLR) connection.

Figure 5: Waterflow Signal Connection

Shows the connection of the PS10 to a fire alarm panel to signal waterflow, also using an End-of-Line Resistor (EOLR) connection.

Figure 6: Local Bell For Waterflow Connection

Details the wiring for connecting the PS10 to a local bell for waterflow indication, showing connections to LINE, LOAD, and BELL terminals, with polarity considerations for DC or AC power.

Figure 7: One Conduit Wiring

Demonstrates a method for wiring both switches of a two-switch model from a single conduit entrance by breaking out a section of the internal divider.

Figure 8: Switch Operation

Explains the switch contact behavior based on pressure. It shows terminal configurations (Common, 1, 2) and how they change state when pressure is applied or not applied, indicating their use for low-pressure supervision or waterflow indication.

Figure 9: Removing Knockouts

Provides a visual guide on how to remove a knockout plug from the device enclosure using a screwdriver and applying force.

Engineer/Architect Specifications

Pressure type waterflow switches shall be a Model PS10 as manufactured by Potter Electric Signal Company, St. Louis, MO, and shall be installed on the fire sprinkler system as shown and/or specified herein.

Switches shall be provided with a 1/2" NPT male pressure connection and shall be connected to the alarm port outlet of Wet Pipe Alarm Valves, Dry Pipe Valves, Pre-Action Valves, or Deluge Valves. The pressure switch shall be actuated when the alarm line pressure reaches 4 - 8 psi (0.27 - 0.55 bar).

Pressure type waterflow switches shall have a maximum service pressure rating of 300 psi (20.68 bar) and shall be factory adjusted to operate on a pressure increase of 4 - 8 psi (0.27 - 0.55 bar).

Pressure switches shall have one or two Form C contacts, with a switch contact rating of 10.1 Amps at 125/250 VAC and 2.0 Amps at 30 VDC.

Pressure type waterflow switches shall have two conduit entrances, one for each individual switch compartment, to facilitate the use of dissimilar voltages for each individual switch.

The cover of the pressure type waterflow switch shall be Weather/UV/Flame Resistant High Impact Composite with a rain lip and shall attach with one tamper-resistant screw. The pressure type waterflow switch shall be suitable for indoor or outdoor service with a NEMA 4/IP66 rating.

The pressure type waterflow switch shall be UL, ULC, and CSFM listed, FM and LPC approved, and NYMEA accepted.

Ordering Information

Tamper Protection

The cover incorporates a tamper-resistant fastener that requires a special key for removal. One key is supplied with each device. For an optional cover tamper switch kit, order Stock No. 0090200. Refer to bulletin #5401200 PSCTSK.

Important Notes and Warnings

WARNING: Installation must be performed by qualified personnel and in accordance with all national and local codes and ordinances. Shock hazard. Disconnect power source before servicing. Serious injury or death could result. Read all instructions carefully and understand them before starting installation. Save instructions for future use. Failure to read and understand instructions could result in improper operation of the device, resulting in serious injury or death. Risk of explosion. Not for use in hazardous locations. Serious injury or death could result.

CAUTION: Do not tighten by grasping the switch enclosure. Use wrenching flats on the bushing only. Failure to install properly could damage the switch and cause improper operation, resulting in damage to equipment and property. To seal threads, apply Teflon tape to male threads only. Using joint compounds or cement can obstruct the pressure port inlet and result in improper device operation and damage to equipment. Do not over-tighten the device; standard piping practices apply.

Service Life: Pressure switches have a normal service life of 10-15 years. However, the service life may be significantly reduced by local environmental conditions.