Red Seal Electrician Practice
Safety and work practicesQuestion 283 of 1506

Why are ungrounded power systems considered dangerous?

  1. A ground fault may occur anywhere, so voltage to earth varies
  2. They always run at a much higher line voltage than grounded
  3. They cannot be isolated using any kind of disconnect
  4. They produce more fault current than grounded systems do
Show answer

Correct answer: A ground fault may occur anywhere, so voltage to earth varies

An accidental ground at any point changes which wire is safe, so you cannot assume any wire is safe.

Source: Troubleshooting Motors and Controls (Dickson-Self), 1.1: Safety

Practice safety and work practices

Questions last reviewed: 18 October 2026