Fact check: Do subpanels in an apartment building require main breakers

1. Summary of the results

Based on the analyses provided, subpanels in apartment buildings typically do not require main breakers. Multiple sources confirm this electrical principle:

• Three Crowns Electric indicates that subpanels do not require a main breaker because the main panel's breaker protects them ^[1]
• Beck Electric states that while single-family dwellings built from the 1980s onward have main breakers on main panels, subpanels and main panels in older homes or multi-unit dwellings may not require a main breaker ^[2]
• A forum discussion shows electrical contractors debating this issue, with the consensus being that main breakers are not required for subpanels within the same structure ^[3]

Technical sources further support this conclusion:

• One source explains that a subpanel typically does not have a main breaker, as it is fed by a double-pole 240-volt breaker at the main service panel ^[4]
• Installation guides confirm that subpanels typically have no main breaker, as the feeder breaker in the main panel acts as the main disconnect for the subpanel ^[5]

2. Missing context/alternative viewpoints

The original question lacks several important contextual factors:

• Code compliance variations: The analyses reference National Electrical Code (NEC) requirements, but local jurisdictions may have different interpretations ^{[6] [7]}
• Inspector discretion: The forum discussion reveals that some inspectors may require main breakers for subpanels even when not technically required by code, creating real-world compliance issues ^[3]
• Dwelling unit considerations: Sources suggest that each dwelling unit may need a main disconnect, which could affect subpanel requirements in apartment buildings differently than in single-family homes ^[7]
• Age and type of building: Requirements may vary based on when the building was constructed and its specific configuration ^[2]

3. Potential misinformation/bias in the original statement

The original question itself does not contain misinformation, as it is posed as a genuine inquiry rather than making a claim. However, the question could benefit from additional specificity:

• Lacks jurisdictional context: Electrical codes can vary by location, and the question doesn't specify which code authority applies
• Missing building-specific details: The question doesn't address whether this concerns new construction, renovation, or existing installations
• Oversimplification: The question treats all apartment building subpanels as identical, when different configurations and local interpretations may create varying requirements

The analyses show that while the general electrical principle is clear (subpanels don't typically need main breakers), real-world application can involve inspector interpretation and local code variations that aren't captured in the original question.