High Voltage Safety; High Voltage Safety System - Lexus LS600L Dismantling Manual

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, along the propeller shaft and transmission tunnel to the power control unit.
The power control unit contains a circuit that boosts the HV battery voltage from 288 to 650
Volts DC. The power control unit creates 3-phase AC to power the motor and generator
located in the transmission. Power cables are routed from the power control unit 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

N A high voltage fuse n* provides short circuit protection in the HV battery pack.
N Positive and negative high voltage power cables o* connected to the HV battery pack are
controlled by 12 Volt normally open relays p*. When the vehicle is shut off, the relays
stop electricity 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.
N Both positive and negative power cables o* are insulated from the metal chassis, so there is
no possibility of electric shock when touching the metal chassis.
N
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 q*
will illuminate the master warning light
"CHECK HYBRID SYSTEM" on the multi-information display.
N
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.
in the instrument cluster and indicate
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