000			01897nab a2200181 4500
005			20260520001047.0
008			260224s2011 xxu
245	0	0	_aAn evaluation of old armored cables in building wiring systems
260			_a _b _cene. 2011
270			_a19/07/2011 ; 19/07/2011
300			_a31 p. ; 107-147
520			_aTranscripción del resumen del autor. Armored cable has been used in building wiring systems since the early 1900s and remains an accepted wiring method today. The original product developed in the early 1900s and that which is commercially available today have significant differences in construction and performance. Likewise the demand and expectation of building wiring systems has changed. This paper explores some of those differences as well as concerns and hazards presented by the continued use of older constructions of armored cable. Testing was performed on samples of aged cables removed from service to determine impedance and temperature rise of the armor when conducting AC current. The results were compared to the DC resistance of the armor as well as the applicable Underwriters Laboratories standard. The performance of cable samples was also tested in construction configurations likely to be encountered in buildings. Results indicate that ground fault currents conducted via the armor of older cable constructions can result in fire and shock hazards where the impedance and circuit characteristics limit the fault current to below the trip level of the circuit overcurrent protective device. Temperature rise of the armor can easily exceed the rating of the conductor insulation contained therein and in some cases present a fire hazard to combustible material in contact with the cable.
581			_a1
773	0		_tFire Technology _g47
942			_cARTICULO
100	1		_aSleights, John E. _950853
999			_c184024 _d184024