Arc Mapping Test Setup

The following photos address tests performed relating to arc mapping. In the test setup, wires were held by staples in the ceiling. The wires were energized with 120 VAC, but were not terminated (open) so that no current flowed through the conductors except during arcing. As can be seen, the conductors (AWG 14-2) were evenly spaced in both cardinal directions (normal to each other). Immediately before the test, final energization tests were performed to confirm the conductor's placement and designation. At test initiation all of the circuits were energized. Each cable constituted a single 15-amp rated circuit.

Multi-meters were arranged on the main circuit feeder lines to determine the time of circuit breaker operation. In one set of tests, voltage was recorded an in another set of tests, current was recorded. The multi-meters were linked to PCs via IR to transducer output from the meter to USB input on the PCs. Data was collected from pre-ignition to the earlier of either all circuits arced or an order for termination from fire command. In all cases, all circuits arced prior to suppression efforts and therefore an "all-clear-electric" call preceded a call from fire command to secure the electric circuits.

Post Test

Following the tests, the recorded PC data was secured. The conductors were removed from the ceiling and examined. In all test cases, all of the conductors arced at some point and the circuit breakers de-energized the circuit. Each conductor was marked as to its location and relationship to the particular circuit breakers. The conductors were then examined for the locations of the arcs and each arc's distance from the end of the cable was recorded. The final two pictures on this test give examples of two arcs.