Journeyman Electrician Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

When multiwire circuits are supplied by single-pole switches or circuit breakers in a common panel, this installation is classified as a violation of the National Electrical Code (NEC) rules. Multiwire branch circuits consist of two or more hot conductors that share a common neutral. According to NEC requirements, these circuits must be protected by a double-pole circuit breaker or a two-pole switch to ensure that all conductors are disconnected simultaneously during a fault or maintenance.

Using single-pole switches or circuit breakers can lead to dangerous conditions, such as live conductors remaining energized while others are turned off, posing a risk of electrical shock or fire. This lack of proper disconnection creates an unsafe situation and is explicitly against NEC standards, which prioritize safety and proper electrical installation procedures.

Therefore, this scenario is indeed a violation of the NEC rules, highlighting the importance of following code regulations for safe electrical practices.