Smoke was seen coming out of the outside wall of a duplex condominium. Directly behind the wall was the kitchen. The Romex cable connected to the dishwasher in kitchen had overheated. The problem was traced to an over tightened wire clamp at the dishwasher's junction box. The electrical path was between the "hot" and grounding conductor (safety ground). The grounding conductor was not connected to the frame of the dishwasher. Even though the cable overheated and there was evidence that the conductors briefly came in contact with each other, the 20 amp circuit breaker never tripped. The abrupt changes in the condition of the cable were due to fiberglass batt insulation preventing the cable from cooling. Fiberglass batt insulation is often split and placed on both sides of a Romex cable.
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There were nicks in the conductors where contact was made.
The nicks were found by finger tracing the conductors. .