High Voltage Safety System - Hyundai NEXO Emergency Response Manual

High Voltage Safety System

2
Fuel Cell Stack
Hydrogen electric vehicles, unlike regular internal combustion engine vehicles, use high voltage
electrical energy generated in the fuel cell stack as a power source. Due to this high voltage
electricity, the vehicle requires careful handling due to the high voltage hazard. The following items
are safety guidelines of the high voltage in the fuel cell stack of NEXO.
1)A metal chassis and electro-conductive enclosure is located in the fuel cell stack to prevent an
electrical shock due to the direct or indirect contact of users. The fuel cell stack has a high
protection degree of IPXXB.
2)Live parts and high voltage buses, which are generating over 400V DC in the fuel cell stack, are
designed to maintain a reliable insulation resistance with an electro-conductive enclosure. When the
insulation resistance is lower than a specified value, the user is notified and the output current of
fuel cell stack is limited.
High Voltage Battery System
This system supplies the energy which is applied during vehicle acceleration. The system is also
used to store the energy generated during regeneration braking.
1) The high voltage system is located in trunk area and is protected with a steel case.
2)The system consists of 64 cells. Each cell is sealed with an aluminum case to protect against an
electrolyte spillage. There is a rare possibility that the electrolyte in the cell will spill, even if the
battery module is cracked.
3) For safety, an over-current protection and ceramic coating isolation layer are used.
4)Non-flammable electrolyte material is used to prevent explosions or fire in an emergency case
such as a car accident.
5) High voltage cables (orange color) connect the battery system to the DC converter.
6)There is a high voltage regulator used to control the high voltage line. In addition, a high voltage
fuse and a safety plug are used to separate the electrical sources in the system for safety.