No technology located in a circuit breaker or fuse panel could detect a high-resistance wiring fault, as no measurable characteristic exists that differentiates a glow fault from normal branch circuit operation.
Power Fault Circuit Interrupters (PFCI) located in receptacles are designed to prevent fires caused by glowing connections in premise wiring or panels. From the receptacle, a PFCI can detect the voltage drop when high current exists in a high resistance junction. In a properly designed circuit, substantial voltage drops should never occur. Proper wire terminations inside utilization equipment (e.g. appliances, lamps, heaters) and cords prevent high-resistance connections that can lead to fires.
Excess current can heat entire lengths of wire. Thermal circuit breakers are designed to protect against excess current through the permanent circuit wiring. However, excess current through the smaller wires in utilization equipment can exist, at levels below the trip thresholds of a circuit breaker.
Overload fault circuit interrupters (OFCI) are designed to protect against excess current drawn by utilization equipment. OFCIs must be located within receptacles. Both thermal circuit breakers and OFCIs are required to prevent fire ignition from excess current.
from wiki>
http://en.wikipedia.org/wiki/Arc-fault_circuit_interrupteranyone ever heard of, or seen these devices ?
~S~
