An alarm phone line goes in fault several times a day. What is the likely cause?

• A. Long distance interference
• B. Ground start malfunction
• C. Power surge
• D. Tampering

Answer: (B)

The situation points to how the alarm panel uses the telephone line to dial out. In ground start signaling, the panel relies on a solid earth/reference ground to seize the line and begin a call. If that ground path is faulty, loose, wet, or intermittently connected, the signaling can be interpreted as a fault on the line. That makes the panel repeatedly register a fault on the phone line as it tries to initiate transmissions, which is why a ground start malfunction is the most likely cause when the line faults several times a day.

Other possibilities don’t fit the pattern as well. Long distance interference tends to cause noise or garbled signals rather than a recurring fault condition on the line. A power surge typically affects the system’s power supply or electronics more broadly, not just the phone line faults. Tampering could cause issues, but it wouldn’t normally produce the regular daily fault pattern seen with a grounding problem.