Per 404.8(B), where switches or other devices are ganged in a four-gang box, and the voltage between adjacent switches exceeds 300 volts, which of the following is required?

• A. Equipped with identified, securely installed barriers between adjacent devices
• B. Equal distribution of load between devices
• C. Nonconductive barriers only
• D. No barriers required

Answer: (A)

When switches or devices are grouped in a four-gang box and the voltage between adjacent devices exceeds 300 volts, you must physically separate the devices with barriers. This helps prevent arcing or accidental contact between high-voltage parts inside the same enclosure, which is a safety risk.

The required approach is to use barriers that are identified for this purpose and securely installed between adjacent devices. “Identified” means the barrier is specifically designated for use as a separator, and “securely installed” means it’s fixed so it won’t move or become dislodged during installation or use. This directly addresses the safety concern posed by high voltage differences in a shared box.

Load distribution between devices is not what this rule addresses, and limiting barriers to nonconductive materials only would not reflect the identified-barrier requirement. Saying no barriers are needed would ignore the safety need when the voltage gap is this large.