New York State Master Electrician Practice Exam

What is the maximum internal current that is permitted through a line isolated monitor when any point of the isolated system is grounded?

1. 0.5 milliamperes

2. 1 milliamperes

3. 2 milliamperes

4. 5 milliamperes

The correct answer is: 1 milliamperes

The correct maximum internal current permitted through a line isolated monitor when any point of the isolated system is grounded is 1 milliamperes. This limit is set to ensure safety in electrical systems, particularly in healthcare facilities and industrial applications where isolated systems are employed. Isolated systems, often used to prevent ground faults, require careful monitoring of the current that may flow through the system if a fault occurs. The 1 milliampere limit is established to minimize the risk of electric shock and to ensure that any current that flows as a result of grounding does not exceed levels that could be hazardous to individuals. When the internal current exceeds this threshold, it could indicate a potential fault condition, which necessitates immediate attention to prevent safety hazards. This standard reflects the industry’s commitment to maintaining safe operating conditions, especially in environments where personnel might be in close proximity to electrical equipment. Other values like 0.5, 2, and 5 milliamperes are not in alignment with established regulations concerning isolated monitors, making them unsuitable as maximum thresholds.