Which of the following equipment will fail if both Static Inverters (SIVs) are defective?

When both Static Inverters (SIVs) are defective, a significant number of essential systems lose their power supply, leading to a cascade of failures. Static Inverters are responsible for converting DC power into AC power, which is necessary for operating various equipment.

The traction motors, which power the trains, depend on the inverters for the DC to AC conversion process. If the SIVs fail, these motors cannot function, leading to a loss of propulsion.

Additionally, auxiliary systems such as battery chargers and air conditioners also rely on the inverters to provide the necessary voltage and current for operation. The electrical systems that support functions like climate control and the charging of auxiliary batteries will likewise cease to operate.

The traction control unit (TCU) also requires power from the SIVs for its operations since it coordinates the functions of the train's propulsion systems and other onboard electrical functions. Without power from the SIVs, all these components would be non-functional, confirming that this choice captures the full range of critical systems affected by the failure of both SIVs.