Electrician's Licensing Practice Exam

Do receptacles fed from subpanels need to be grounded to a neutral bar?

1. Yes, always

2. No, they can remain isolated

3. Only if it is a dedicated subpanel

4. Yes, but only for older installations

The correct answer is: Yes, always

In electrical installations, grounding and bonding are critical for ensuring safety and proper operation. When it comes to receptacles fed from subpanels, it is essential to understand that typically, the neutral and ground conductors must be separated at a subpanel. The grounding must bond to a ground bar, not the neutral bar, to prevent potential hazards such as shock or fire caused by improper grounding. However, the correct response emphasizes the necessity of grounding, highlighting the importance of grounding systems across installations to protect against electrical faults. This grounding process is vital because it provides a path for fault currents, ensuring that overcurrent protection devices, such as breakers, will trip in a fault condition. Additionally, newer electrical codes and standards dictate that receptacles, regardless of whether they are fed from main panels or subpanels, must be grounded properly to maintain system integrity. This promotes safety and compliance with established standards and practices in electrical work. The other options suggest varying degrees of grounding practices that may not align with the current electrical codes. For instance, stating that grounding can be isolated undermines safety protocols that require a grounded system for all receptacle installations.