DC CIRCUIT FAULTS Basic DC TheoryDC CIRCUIT FAULTSFaults within a DC circuit will cause various effects, depending upon the natureof the fault. An understanding of the effects of these faults is necessary to fullyunderstand DC circuit operation.EO 1.16 DESCRIBE the voltage and current effects of an openin a DC circuit.EO 1.17 DESCRIBE the voltage and current effects in a shortedDC circuit.OpenCircuit(Series)A circuit must have a "complete" path for current flow, that is, from the negative side to thepositive side of a power source. A series circuit has only one path for current to flow. If thispath is broken, no current flows, and the circuit becomes an open circuit (Figure 53).Circuits can be opened deliberately, such as by the use of a switch, or they may be opened byFigure 53 Open Series Circuita defect, such as a broken wire or a burned-out resistor.Since no current flows in an open series circuit, there are no voltage drops across the loads. Nopower is consumed by the loads, and total power consumed by the circuit is zero.ES-02 Page 66 Rev. 0