High Voltage Safety - Lexus CT200h Hybrid 2011 Emergency Response Manual

H igh 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, to the
inverter/converter. The inverter/converter contains a circuit that boosts the HV
battery voltage from 201.6 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
breaching any orange high voltage power cable or high voltage
component.
 Both positive and negative power cables  are insulated from the
metal body. High voltage electricity flows through these cables and
not through the metal vehicle body. The metal vehicle body is safe to
touch because it is insulated from the high voltage component.

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.
00
Volt DC
A/C
Compressor

Electric
Generator
Electric
Motor
AC
3-Phase
High Voltage Safety System – Vehicle Shut Off (READY-OFF)
201.6
Volt DC
A/C
Compressor
Electric
Inverter/
Generator
Converter
Electric
Motor
AC
3-Phase
High Voltage Safety System – Vehicle On and Operational (READY-ON)
15
- -
Hybrid Vehicle Computer



Inverter/ 
Converter
00
Volt DC

HV Battery Assembly
Hybrid Vehicle Computer
201.6
Volt DC
HV Battery Assembly
12 Volt
Auxiliary
Battery
12 Volt
Auxiliary
Battery