Photoelectric 4-Wire Smoke Detector w/Heat Sensor, 6 - 33VDC. Smart Dual Fixed/Rate of Rise Heat Sensors. The 541NBXT is a security photoelectric smoke detector from Interlogix which comprises a heat sensor, a 4 wire smoke detector, a UL/cUL listing, and a 6 to 33 VDC power source. The 541NBXT security smoke detector comes with an available in-built sounder, in-built dust protection, a CleanMe® patented feature, plus a field replacement optical chamber. This high grade 4 wire smoke detector can be used with a varied number of control panels due to the low current draw, and is suitable for residential or business premises meeting the requirement of the residential code.