Grounding Conductor and Bonding Resistance: Protective Earth Continuity Review
Grounding conductor and bonding resistance testing confirms whether the protective earth path is continuous and reliable. For electrical products with metal enclosures, protective earth terminals, or accessible metal parts, grounding material, conductor size, fastening method, and contact condition all affect protection under fault conditions.
Common Review Items
| Item | Review focus | Common risk |
|---|---|---|
| Measuring path | Confirm measuring points from protective earth terminal to accessible metal parts | Only the main earth point is measured while doors, brackets, or enclosure sections are missed |
| Test condition | Review test current, duration, instrument calibration, and lead compensation | Instrument lead resistance is not zeroed, affecting low-resistance results |
| Connection structure | Check screws, welds, rivets, terminals, and contact-surface condition | Coating, oxidation, looseness, or washer selection affects contact reliability |
| Conductor and material | Review conductor size, material, harness fixing, and anti-loosening measures | Production wire or terminal differs from the tested sample |
| Criteria and record | Confirm applicable limit, sample status, and abnormal handling | The report does not state measuring positions and construction version |
Report Boundaries
- The report should list test points, instrument model, test current, sample construction, and acceptance basis.
- After enclosure, grounding point, wire, terminal, or assembly-process changes, earth continuity should be reviewed again.
- Low-resistance testing is sensitive to assembly condition; production checks should use the same measuring positions and method.
- Customer-facing pages should avoid presenting one earth-continuity test as a full overall safety conclusion.
Green Ark's Recommendation
Green Ark (Shenzhen) Certification Co., Ltd. recommends building a grounding-path checklist during design and production, defining grounding point, connection method, and inspection method for each accessible metal part. This helps reduce missed earth points, loose assembly, and production-consistency issues.
