Troubleshooting Opens, Shorts, and Ground Faults
Most service calls come down to one of three faults. Knowing the symptom of each tells you where to look.
1. The three faults
| Fault | What it is | Symptom |
|---|---|---|
| Open | a break in the conductive path — no current flows | device is dead, but line voltage is still present upstream |
| Short | an unintended low-resistance path (hot-to-hot or hot-to-neutral) | huge current → breaker trips instantly |
| Ground fault | an ungrounded (hot) conductor contacts a grounded surface/EGC | current diverts to ground → GFCI trips |
2. Reading the symptoms
- Breaker trips immediately on reset → suspect a short.
- GFCI keeps tripping → suspect a ground fault (or a wet device / damaged insulation).
- Device dead but voltage present at its terminals → suspect an open in the device or its connections.