Secondary Neutral-to-Ground bonds are allowed only with a Separately Derived Power Source.

• A. True
• B. False
• C. Only with the main power source
• D. Not specified

Answer: (A)

Neutral-to-ground bonding creates a single reference point for the electrical system. In a normal service setup, the neutral is bonded to ground at the service equipment only. If you add a secondary bond between neutral and ground downstream on a system that isn’t a separately derived power source, you’d end up with multiple bonding points and current could flow on the grounding path. That can cause ground loops, stray currents, and safety and equipment issues.

When a separately derived power source is present—such as a transformer or other source that isolates the secondary system and has its own grounding electrode system—the neutral can be bonded to ground at that source, establishing a defined, single bonding point. In that case, a secondary neutral-to-ground bond is permitted because it won’t create conflicting ground paths; the bond is at the designated source and keeps the system referenced properly.

So the statement is true: secondary neutral-to-ground bonds are allowed only with a Separately Derived Power Source. If the system isn’t separately derived, such a bond would introduce unwanted parallel paths for current and is not permitted.