The listed spacing should be used as a guide or starting point in the 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, XCR, and XLT: 30 feet (9.14m) 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 are rated for proximity detection only and do not have a rated spacing
  • Underwriters Laboratories Listed Spacing for All Models: 50 feet (15.24 meters) on center