EVT EVT Charging Systems & Infrastructure 2

Question 1

What does a Ground Fault Circuit Interrupter (GFCI) monitor in an EVSE installation to protect users?

Accepted Answer

Current imbalance between hot and neutral conductors

Answer

A GFCI detects a difference between the current on the hot and neutral conductors—indicating current is leaking to ground—and interrupts the circuit.

Question 2

A DC fast charger rated at 150 kW charges a vehicle with a 400V battery pack. Approximately how many amps does it deliver?

Accepted Answer

375 A

Answer

Current = Power / Voltage = 150,000 W ÷ 400 V = 375 A.

Question 3

What is the primary function of the on-board charger (OBC) in an electric vehicle?

Accepted Answer

Convert AC grid power to regulated DC for battery charging

Answer

The OBC converts AC supply voltage from the grid or EVSE into the correct DC voltage and current needed to charge the high-voltage battery pack.

Question 4

When inspecting a CHAdeMO DC fast-charge port, a technician notices severe corrosion on the large power pins. What is the FIRST corrective action?

Accepted Answer

Tag out, remove from service, and replace the inlet assembly

Answer

Corroded high-current DC inlet pins can cause arcing, overheating, or fire; the inlet must be taken out of service and replaced before reuse.

Question 5

Which EVSE level provides the fastest charging rates currently available to passenger EVs at public stations in the US?

Accepted Answer

DC Fast Charge (Level 3)

Answer

DC Fast Charge (Level 3) stations deliver power directly as DC at up to 350+ kW, far exceeding Level 1 and Level 2 AC rates.

(EVT) Certified Electric Vehicle Technician Practice Test