In a Class B circuit, what happens if a fault occurs?

In a Class B circuit, what happens if a fault occurs?

• A. The entire system shuts down.
• B. Only devices near the fault are affected.
• C. The control panel detects the fault.
• D. A fault may disable devices along that loop.

Answer: (D)

Class B circuits carry signaling along a single path from the panel to devices and back. If a fault occurs, there’s no alternate route around it, so continuity is broken and devices beyond the fault on that loop can no longer be energized or monitored. In other words, the fault may disable devices along that loop. The panel will typically show a trouble on that circuit, but the crucial effect is the loss of operation for downstream devices on that same path.

Class B circuits carry signaling along a single path from the panel to devices and back. If a fault occurs, there’s no alternate route around it, so continuity is broken and devices beyond the fault on that loop can no longer be energized or monitored. In other words, the fault may disable devices along that loop. The panel will typically show a trouble on that circuit, but the crucial effect is the loss of operation for downstream devices on that same path.