The 120V/277V Phase Loss Sense Panel (PLSP) is a cETLus and UL924-listed power sensing device designed for single phase or three phase applications. This latest generation of the PLSP supports both 120V and 277V applications, monitoring normal power feeds and fire alarm control panels (FACPs), detecting outages and alerts. When a power loss or alert is detected, the PLSP signals the connected devices to enter their emergency state, ensuring that, upon a power loss, the entertainment luminaires, house lights, and other connected devices will come on to the desired emergency state.

    The PLSP offers three separate change-over contact outputs that can each be independently set to normally open or normally closed. Integrators can control up to 5 devices per output when daisy chained, including our power devices, Vision.Net controlled devices (via the 4-Port Digital I/O Module or 8-Port Digital Input Module), our Emergency Bypass Switch, or even third-party contact closure devices.

    The PLSP also includes capabilities that ensure the system works as users expect both during normal operation and emergencies. The system includes variable delay timing with a field-configurable delay setting to prevent nuisance triggers, providing a more stable system and avoiding long system reboot times unnecessarily. For applications such as theatrical performances or dark rides at theme parks, the PLSP offers optional remote restore functionality that ensures that lights will not return to their previous “dark” state without manual intervention. Integrators have the option to connect a third-party button, switch, or other manual trigger to the PLSP to manually return the system to the previous state.

    To simplify life for support technicians, the PLSP offers user feedback and testing features right on the front panel. The panel offers phase indicators that provide power status per phase, as well as test buttons that allow techs to test the system operation during routine maintenance without cutting power to the section of the building. While pressed, the test button initiates a momentary physical tripping of power, replicating an emergency situation. Like the indicator lights, test buttons are available for each phase, providing better support for three-phase applications.


    • 120V / 277V phase loss detector – monitor normal power feed for outages with a cETLus and UL924-listed sensing device. Signals connected devices to enter their emergency state
    • Single-phase and three-phase support – works with more power applications
    • Three independent contact closure outputs with 5 identical daisy-chained devices per output – connect to multiple different devices and device types
    • Changeover contact input for Fire Alarm Control Panels (FACPs) – respond to fire alerts by connecting normally open or normally closed contact
    • Field-configurable variable delay timing – optional delay setting to prevent nuisance triggers
    • Optional remote restore – connect a third-party control device to manually restore the system rather than using automatic restore. Improve safety in dark environments
    • Phase indicators – check system status by phase using easily viewable onboard indicators
    • System test buttons for each phase – physically disconnect power by phase for ease of system testing
    • Flush or surface mount – install the PLSP where you need it

    Product Summary, Documentation and Downloads