NEC Commercial Electrical Practice Test

Which conductor should not be disconnected by switches or circuit breakers except where allowed?

1. Hot conductor

2. Neutral conductor

3. Grounded conductor

4. Ground conductor

The correct answer is: Grounded conductor

The grounded conductor is one that typically should not be disconnected by switches or circuit breakers except in specific situations where allowances are made. This conductor is normally tied to the earth and is used to safely carry any fault current back to the source to help protect against electrical shock and fires. In most electrical systems, the grounded conductor is the neutral wire, which is designed to provide a return path for current. Disconnecting this conductor can disrupt the balance of the electrical system and create a potential hazard, especially in multi-wire branch circuits or in systems where the neutral is shared. The National Electrical Code (NEC) emphasizes the importance of keeping the grounded conductor connected as a safety measure, allowing disconnection only in certain allowable scenarios, such as when equipment requires maintenance or for specific disconnecting means where the risk has been evaluated and deemed safe. The other conductors, such as hot conductors, do require switching or circuit breakers to disconnect for safety and operational purposes, allowing for control of the electrical flow. Ground conductors are related to safety and are not intended for disconnection due to their essential role in providing a path to ground in case of a fault.