Protectowire Digital Linear Heat Detector is the most widely used linear heat detector in the fire detection industry. It is a continuous heat detector capable of detecting heat anywhere along its length. The sensor cable is comprised of two steel conductors individually insulated with a proprietary heat sensitive polymer. The insulated conductors are twisted together to impose a spring pressure between them, then wrapped with a protective tape and finished with a protective outer jacket.
Frequently Asked Questions
Protectowire PLR models are manufactured with special low resistance tri-metallic inner conductors that enable the use of longer detector zone lengths on most types of fire alarm panels including addressable.
The maximum length of Protectowire Digital Linear Heat Detector that will be compatible with a manufacturers fire alarm control panel is determined by the initiating device circuits maximum loop resistance and the per unit length resistance of the linear heat detector. Lower per foot resistance allows for longer detector lengths on the same circuit.
Protectowire’s PHSC digital linear heat detectors have an approximate resistance of 0.185 Ohms per foot (0.607 Ohm per Meter).
Protectowire’s PLR digital linear heat detectors have an approximate resistance of 0.058 Ohms per foot (0.191 Ohm per Meter).
PLR models will allow for installed detector lengths approximatly 3x longer on the same initiating device circuit.
Yes, the electrical characteristics of the Protectowire Linear Heat Detector are compatible with most manufacturers control panels. The system designer should confirm Protectowire Linear Heat Detector compatibility with the panel manufacturer. Limitations in the length of Protectowire per zone must be determined due to the resistance of the conductors. Protectowire Control Panels are specifically designed and approved for use with Protectowire Linear Heat Detectors and are recommended to insure compatibility and provide sole source system responsibility.
The listed spacing shall be used as a guide or starting point in detector installation layout. Reduced spacing is required based upon factors such as ceiling height and construction, physical obstructions, air movement, or the Authority Having Jurisdiction (AHJ).
The maximum listed spacing for each type of Protectowire Linear Heat Detector is as follows:
Factory Mutual Listed Spacing for 155°F and 190°F rated Types EPC, EPR, XCR, and XLT – 30 feet (9.14m) on center, Type TRI – 15 feet (4.6 meters) on center. Protectowire 220°F and 280°F Types EPC and XCR – 25 feet (7.6m) on center. Protectowire 356°F Types EPC and XCR rated for proximity detection only and do not have a rated spacing.
Underwriters Laboratories Listed Spacing, for all models (except Type TRI) – 50 feet (15.24 meters) on center. Type TRI is FM approved only and not UL Listed.
Yes, Protectowire Linear Heat Detectors (Excluding Tri-Wire) have the same internal construction and can be spliced directly together on the same initiating device circuit. This allows a single Protectowire Linear Heat Detector zone to protect multiple areas with different ambient temperatures.
All Protectowire FireSystem Control Panels can be provided with our unique Alarm Point Location Meter. This feature allows the control panels to digitally display the linear distance (feet / meters) to the point of overheat.
- Detects at any point along its length providing uniform sensitivity.
- Available in a wide range of operating temperatures and outer jackets.
- Provides alarm point location with suitably configured control panels.
- Simple design for easy troubleshooting and low maintenance costs.
- Outer jackets resist corrosion, chemicals, dust, dirt, moisture, and temperature extremes.
- Protectowire Linear Heat Detector product data sheet.
- Protectowire Linear Heat Detector product data sheet – Spanish.
- Protectowire Linear Heat Detector product line chart.
- Installing Protectowire Linear Heat Detector data sheet.
- Installation, Operation, and Maintenance Manual for Protectowire Linear Heat Detector.
- Protectowire Linear Heat Detector Important Installation Instructions.
- Protectowire Linear Heat Reference Guide