Electrical Circuit Defects

Electrical circuit defects car be categorized in three types. These are open circuit, short circuit and high resistance. Any electrical circuit either complex or simple will have only one or more than one of all these three defects. There is no chance of the fourth defect as fourth defect don’t occur in electrical system. Due to these three defects electrical system don’t operate correctly or don’t operate at all. Proper understanding and familiarization with such defects is the key to properly and effectively diagnose and troubleshoot electrical problems and defect in any electrical system. We will discuss in detail all these three defects below.

Open circuit

Open circuit is break in the electrical circuit or path. The electrical circuit must be a complete circuit to work. Open circuit don’t allow electricity to pass. Hence the circuit would not work if it is open. Open circuit is caused by defective or broken wire, defective or open switch, blown out light bulb, blown fuse, open circuit breaker or a defective or broken connector or splice. Electrical circuit works in the principle that all voltage of the system should drop on the load in the circuit. Due to open circuit the voltage is not applied to load and no current could pass through the load. So the load don’t work. An open circuit effect the circuit if open is there before the load or after the load. Open circuit occurs in electrical circuit due to mechanical injury to wiring or other electrical component or sometimes due to excessive current flow in the system burns and open circuit components.

Short circuit

Short circuit is due to creation of unwanted paths in electrical circuits. These paths are normally created in wiring or inside the devices. Electricity tends to find shortest possible path to complete the circuit. Wires are travelling together in a system. In case of weak insulation of cables they make connections to each other and current starts to pass in those connections. Other way is sometimes coils winding insulation breaks down and an inter turn short circuit occurs which leads to heavy current draw by the coil and improper operation of the coil. Also excessive heat will be generated from that coil due to heavy current draw. Short to ground is also a fault most commonly occur in electrical systems. In short to ground fault the current carrying conductor shorts to neutral or ground and it sees a short and easy path this way. In automotive as body and chassis is metallic and connected to the earth or battery negative, such type of short circuiting is very common.

High Resistance

High resistance problem or defect occurs in electrical system when an un-engineered voltage drop is created in the circuit due to wrong operation of the circuit.