What will happen if high-voltage from the HV battery or motor generator is shorting to ground?
Answer: Unlike a low voltage battery such as 12V, high voltage from a High Voltage battery should not be grounded to the chassis for several numbers of reason which are; -HV can result to surges which result to spark over and flash over between phase and ground.
What does the purpose of the service disconnect on a HV battery?
A fourth safety device used within a high voltage battery pack is called a manual service disconnect (MSD). This device is a method for breaking the electrical continuity within the pack for the purpose of vehicle service. The MSD is often a touch safe, removable enclosure containing the fuse.
What actions are needed to disable the high-voltage HV circuit?
The high-voltage system is deactivated by first switching on the high-voltage system, ie putting it under high voltage (“KU 5 on”) . The motor vehicle or at least the high-voltage system is switched to the operating state by means of an “ignition key” or other starting device.
What tool is needed to test a high-voltage hybrid system?
For example, disconnecting HV components can be useful when diagnosing a hybrid vehicle’s ground fault. Such work requires the use of a milli-ohmmeter or insulation tester, which will be covered in a future article.
How many volts are present in a fully charged 12-volt battery?
12.6V volts
12.6V volts or above – Your battery is healthy and fully charged. No further action is required. 12.5 volts – Your battery is at a healthy state of charge, but we’d recommend re-checking it within a few days to ensure the voltage hasn’t dropped any further.
What is manual service disconnect?
SAE standards require the function of a Manual Service Disconnect (MSD), when open, to remove any voltage between positive and negative Rechargeable Energy Storage System (RESS) output terminals.
How are high voltage vehicles identified?
All high voltage components, or compartments that house high voltage components, are identified with a hazardous voltage label that generally incorporates a yellow triangle with a black thunderbolt, and warning text. If one or more such labels is present on a vehicle it has a high voltage electric drive system.
What safety precautions exist in high voltage vehicles?
To ensure technician safety, proper high-voltage PPE should be used, such as gloves (rubber and leather), boots, face shields and safety glasses. Technicians should always be fully trained and read OEM high-voltage disable procedures and precautions before working on hybrid and electric vehicles.
What happens when reverse battery polarity is applied?
With reverse applied voltage, a short circuit via diodes or transistors could occur, leading to fatal errors of the electronics of the car. This means, that the ECUs (Electronic Control Unit) have to be protected against reverse battery polarity. 3 Possible Solutions In this chapter three most common reverse battery protection circuits will be
How are ECUs protected from reverse battery polarity?
This means, that the ECUs (Electronic Control Unit) have to be protected against reverse battery polarity. 3 Possible Solutions In this chapter three most common reverse battery protection circuits will be discussed. A solution with relay is not taken into account. 3.1 Reverse Battery Protection with Diode
What are the effects of polarity on electronics?
Polarity is a result of an “accident,” but the effects can be damaging. Nowadays, much of the gear that can be bought in the marketplace may be damaged by polarity because of poor design techniques. There is an area in design where manufacturers are often at fault.
How are power losses determined in reverse battery protection?
The power losses of an n-channel MOSFET for a reverse battery protection are determined by the R DS(on)of the device and the load current. Switching losses can be neglected because the device will be switched on once when the battery is applied and stays in on state during normal operation. The power losses and ratio