EEI TECH VIP Practice Exam

Read the following passage, then answer the question. --- ELECTRICAL DISTRIBUTION SYSTEM MAINTENANCE Electric utility workers must follow strict lockout/tagout (LOTO) procedures when working on energized or potentially energized equipment. The LOTO process requires workers to isolate the energy source, lock the energy isolation device in the OFF position, and test to verify that the equipment is de-energized before beginning work. Each authorized employee who is working on the equipment must apply their own personal lock to the isolation device. The lock remains in place until that specific employee has completed their work and has moved to a safe location. Under no circumstances should one worker remove another worker's lock. When working on distribution lines, crews must also identify all possible energy sources, including backfeed from customer generators and capacitor banks, which can retain charge even after a circuit is de-energized. Grounding conductors must be applied at the work site to protect against unexpected re-energization. Ground fault circuit interrupters (GFCIs) are required on all temporary power at construction and utility work sites. A GFCI monitors the balance of current flowing through the hot and neutral conductors. If the GFCI detects a difference of as little as 5 milliamps, it trips within 1/40th of a second, potentially saving a worker's life by interrupting the circuit before ventricular fibrillation can occur. --- According to the passage, what is the MINIMUM current imbalance that will cause a GFCI to trip?

Questions 2–31 and full explanations are VIP-exclusive.