Where separate equipment grounding conductors and supply-side bonding jumpers are installed in a dry-type transformer enclosure, which of the following is required for all grounding and bonding conductor connections?

Where separate equipment grounding conductors and supply-side bonding jumpers are installed in a dry-type transformer enclosure, which of the following is required for all grounding and bonding conductor connections?

• A. An impedance-rated noncombustible separator shall be installed
• B. A terminal bar shall be secured inside the transformer enclosure
• C. A separate raceway shall be installed
• D. A legible directory shall be posted in a conspicuous location

Answer: (B)

The key idea is that there must be a single, accessible termination point inside a dry-type transformer enclosure for all grounding and bonding conductors. A terminal bar secured inside the enclosure provides that dedicated point, giving a listed, sturdy connection for each grounding conductor and bonding jumper to bond to the enclosure and to each other. This ensures reliable electrical continuity, protects the conductors from damage, and makes inspection and future modifications straightforward, which is why this approach is required. The other options don’t establish the necessary termination point for the grounding and bonding conductors. An impedance-rated noncombustible separator isn’t about terminating conductors, a separate raceway isn’t required for these connections, and a legible directory, while helpful for labeling, doesn’t fulfill the actual termination requirement inside the enclosure.

The key idea is that there must be a single, accessible termination point inside a dry-type transformer enclosure for all grounding and bonding conductors. A terminal bar secured inside the enclosure provides that dedicated point, giving a listed, sturdy connection for each grounding conductor and bonding jumper to bond to the enclosure and to each other. This ensures reliable electrical continuity, protects the conductors from damage, and makes inspection and future modifications straightforward, which is why this approach is required.

The other options don’t establish the necessary termination point for the grounding and bonding conductors. An impedance-rated noncombustible separator isn’t about terminating conductors, a separate raceway isn’t required for these connections, and a legible directory, while helpful for labeling, doesn’t fulfill the actual termination requirement inside the enclosure.