Question 147Electricity & Electronics - QMED

The correct answer is C) magnetic blowout coils. Magnetic blowout coils are used to prevent the burning of controller contacts due to arcing when opening the circuit. The magnetic field created by the coils helps to quickly extinguish the arc, reducing the chances of contact damage and prolonged arcing. This is an effective way to prevent contact damage and ensure the safe operation of electrical equipment. The other options are not the primary means of preventing contact arcing when opening a circuit. Coating the contacts with petroleum jelly (A) may help reduce arcing, but it is not the primary method. Overvoltage (B) and overcurrent (D) releases are designed to protect the circuit from excessive voltage or current, but they do not specifically address the issue of contact arcing when opening the circuit.