Hybrid Book - Chapter 3

According to the SAE J1673 standard, high-voltage covering and/or cabling should be visually identified with orange covering.

The purpose of the isolation-fault detection circuit is to monitor the ground of the vehicle chassis for voltage leakage. This is important because voltage leakage can occur when there is a fault in the electrical system, which can be potentially dangerous. By detecting voltage leakage, the isolation-fault detection circuit can alert the vehicle's controller to take appropriate action to prevent any further damage or safety risks.

When isolation-fault detection, diagnosis, and repair are not performed, it can result in electrical shock. This means that without proper detection and repair of isolation faults, there is a risk of electrical current flowing through unintended paths and causing harm to individuals who come into contact with the system. It is important to regularly perform these tasks to ensure the safety of both the system and the people using it.

A passive discharge circuit uses a resistor to discharge energy in the high-voltage bus capacitors. A resistor is a passive component that dissipates energy as heat when a current flows through it. In this circuit, the resistor provides a path for the discharge current to flow, allowing the energy stored in the capacitors to be safely dissipated. A diode, comparator, and op-amp are not suitable for discharging energy in this context.

A local interlock loop uses LAN communications to open the contractors when the high-voltage system has been breached. This means that the interlock loop relies on a local area network (LAN) to communicate and trigger the opening of the contractors in the event of a breach in the high-voltage system. LAN communications provide a reliable and efficient way to transmit the necessary signals and ensure the safety of the system.

Active and passive systems are the two categories of systems that can discharge system high voltage. Active systems are designed to actively discharge high voltage by using external components such as resistors, capacitors, or transistors. Passive systems, on the other hand, discharge high voltage through natural processes without the need for external components. These processes can include leakage or dissipation of voltage over time. Therefore, active and passive systems are the correct categories for systems that can discharge system high voltage.

The correct answer is "serial and local." Serial and local are two types of interlock loop designs that can be used to monitor a high-voltage system. Serial interlock loops are designed to communicate with each other in a series, where the output of one loop serves as the input for the next loop. Local interlock loops, on the other hand, are self-contained and do not rely on communication with other loops. These two designs provide different options for monitoring and controlling a high-voltage system.

A megohmmeter is used to assist in identifying the location of an isolation fault. An isolation fault occurs when there is an unintended connection between two points that should be isolated from each other. A megohmmeter measures the resistance between two points, and if there is a low resistance reading, it indicates the presence of an isolation fault. By using a megohmmeter, technicians can locate the fault and take necessary steps to fix it, ensuring proper isolation between different components or circuits.

A serial interlock loop system is designed to open battery-pack relays/contactors if its circuit is broken or opened. This means that if there is a fault or interruption in the circuit, the system will automatically open the battery-pack relays/contactors, effectively disconnecting the power source. This is a safety measure to prevent any further propulsion or power flow in the system, ensuring the safety of the equipment and personnel.

The Lexus RX400h and Toyota Highlander hybrids use grounded-switch interlock systems. This means that the interlock systems in these vehicles are designed to ensure that the electrical circuits are properly grounded, preventing any potential electrical hazards or malfunctions. This type of interlock system is commonly used in hybrid vehicles to ensure the safety and reliability of the electrical components.