Lexus IS300h - High Voltage System Safety; High Voltage Safety System Features

High Voltage Safety
The HV battery pack powers the high voltage electrical system with DC electricity. Positive
and negative orange colored high voltage power cables are routed from the battery pack,
under the vehicle floor pan, routed along the propeller shaft and transmission tunnel to the
inverter/converter. The inverter/converter contains a circuit that boosts the HV battery
voltage from 230.4 to 650 Volts DC. The inverter/converter creates 3-phase AC to power
the motor. Power cables are routed from the inverter/converter to each high voltage motor
(electric motor, electric generator, and A/C compressor). The following systems are
intended to help keep occupants in the vehicle and emergency responders safe from high
voltage electricity:
High Voltage Safety System
• A high voltage fuse * provides short circuit protection in the HV battery pack.
• Positive and negative high voltage power cables * connected to the HV battery pack are
controlled by 12 Volt normally open relays *. When the vehicle is shut off, the relays stop
electrical flow from leaving the HV battery pack.
WARNING:
・ The high voltage system may remain powered for up to 10
minutes after the vehicle is shut off or disabled. To prevent
serious injury or death from severe burns or electric shock,
avoid touching, cutting, or opening any orange high voltage
power cable or high voltage component.
• Both positive and negative power cables * are insulated from the metal chassis, so there is no
possibility of electric shock when touching the metal chassis.
• A ground-fault monitor * continuously monitors for high voltage leakage to the metal chassis
while the vehicle is running. If a malfunction is detected, the hybrid vehicle computer * will
illuminate the master warning light
in the instrument cluster and indicate “Check Hybrid
System” on the multi-information display.
• The HV battery pack relays will automatically open to stop electricity flow in a collision sufficient
to activate the SRS.
*Numbers apply to the illustration on the following page.
12