EVT High Voltage Electrical Systems & Wiring

Question 1

What is the standard color code for high-voltage wiring in electric vehicles according to SAE and FMVSS 305 standards?

Accepted Answer

Orange

Answer

Red

Answer

Blue

Answer

Yellow

Question 2

At what minimum DC voltage level are electric vehicle systems generally classified as 'high voltage' under FMVSS 305?

Accepted Answer

60V DC

Answer

12V DC

Answer

36V DC

Answer

120V DC

Question 3

What is the primary purpose of the manual service disconnect (MSD) in an EV high-voltage system?

Accepted Answer

To physically interrupt the HV circuit for safe servicing

Answer

To connect the 12V system to the HV bus

Answer

To balance battery cell voltages

Answer

To reset battery management system faults

Question 4

What is the purpose of the precharge circuit in a high-voltage EV system?

Accepted Answer

To slowly charge large capacitors before main contactors close, limiting inrush current

Answer

To warm the battery cells before charging begins

Answer

To test insulation resistance before vehicle operation

Answer

To balance cell voltages during charging

Question 5

What minimum rubber insulating glove class is required when working on EV high-voltage systems operating up to 1000V?

Accepted Answer

Class 0 (1000V rated)

Answer

Class 00 (500V rated)

Answer

Class 1 (7,500V rated)

Answer

Class 2 (17,000V rated)

Question 6

Which instrument must be used to verify the absence of high voltage before touching HV components after removing the MSD?

Accepted Answer

A CAT III or CAT IV rated digital multimeter

Answer

A standard 12V test light

Answer

A standard ohmmeter

Answer

A battery hydrometer

Question 7

What is the minimum isolation resistance required per volt between the HV bus and vehicle chassis under FMVSS 305?

Accepted Answer

100 ohms per volt

Answer

10 ohms per volt

Answer

1,000 ohms per volt

Answer

10,000 ohms per volt