Potter PE-HSW Fire Alarm 170002

The Potter PE-HSW (P/N 170002) is a horizontal waterflow switch for fire alarm systems designed for wet pipe sprinkler system monitoring. It provides reliable sprinkler flow detection and alarm signalling to Potter fire alarm control panels without the integrated cover tamper switch found on the PE-HSWC (170003). The PE-HSW is the right choice for installations where cover tamper supervision is not required by the system design or local AHJ — providing the same core flow detection performance at a streamlined specification.

Like all Potter waterflow switches, the PE-HSW uses a paddle-type sensing mechanism mounted inside the sprinkler pipe. When a sprinkler head activates and water flows through the pipe, the paddle deflects and closes the alarm contacts, sending a fire alarm notification appliance signal to the connected fire alarm control panel. The adjustable retard prevents nuisance alarms from pressure transients and water hammer that are common in wet pipe systems.

For fire alarm parts suppliers stocking the full Potter PE series waterflow switch line, the PE-HSW (170002), PE-HSWC (170003), and PE-STW (170007) cover the complete range of wet pipe sprinkler monitoring requirements. Having all three variants in your fire alarm supply store inventory ensures you can meet any specification from standard horizontal installations to tamper-supervised configurations.

Horizontal Pipe Installation

The PE-HSW is specifically designed for horizontal pipe runs in wet pipe sprinkler systems. Install per the Potter installation data sheet, ensuring the paddle orientation is correct for the pipe diameter and flow direction. Incorrect paddle orientation will prevent the switch from detecting flow and result in a failed annual flow test.

Retard Setting

Adjust the built-in retard to eliminate nuisance alarms while maintaining alarm transmission within NFPA 72 requirements. The retard setting should be documented in the fire alarm inspection and test records and re-verified after any system modifications that change the flow characteristics of the sprinkler piping.

Annual Inspection and Testing

Test the PE-HSW annually per NFPA 25 using the inspector's test valve. Confirm the fire alarm control panel receives the waterflow alarm signal within the required time. Fire alarm inspection and test records must be retained for the minimum period required by the AHJ. Also verify the wiring connections are secure and the paddle moves freely without obstruction inside the pipe.

When should I choose PE-HSW over PE-HSWC?

Choose the PE-HSW (170002) when cover tamper supervision is not required by your system design or AHJ. Select the PE-HSWC (170003) when the system design or local fire code requires that the waterflow switch housing be supervised for tampering. Both provide identical waterflow detection performance — the difference is only the tamper supervision output.

Can this be used on a vertical pipe riser?

The PE-HSW is designed for horizontal pipe installations. For vertical riser applications, consult Potter's product selection guide to identify the appropriate vertical or multi-directional waterflow switch model. Using a horizontal switch on a vertical riser may result in incorrect paddle orientation and unreliable flow detection.

How do I troubleshoot a PE-HSW that produces constant alarms?

Constant fire alarm signalling from a waterflow switch is most commonly caused by a stuck paddle, a failed retard mechanism, or a wiring fault. First verify the retard is set correctly. Then inspect the paddle for debris or corrosion binding. Finally check the wiring for shorts. If the switch continues to produce alarms after these checks, replace the PE-HSW with a new 170002.