I--- Iec 60060-1 Pdf _hot_ -
Standard Identification
6. Common Misunderstandions (Clarified from the PDF)
Direct voltage
| Voltage type | Definition | Parameters | |--------------|------------|-------------| | | Ripple ≤ 3% (for dry tests) | Average value | | Alternating voltage | Frequency 45–65 Hz | Peak/√2, distortion ≤ 5% | | Lightning impulse (1.2/50 µs) | Front time T₁ = 1.2 µs ±30%, Half-value time T₂ = 50 µs ±20% | Peak overshoot ≤ 10% | | Switching impulse (250/2500 µs) | Front time = 250 µs ±20%, Half-value time = 2500 µs ±60% | – |
- 1989 edition: Permitted only dry and wet tests for external insulation.
- 2010 edition: Introduced detailed procedures for very fast front overvoltages (VFTO) , crucial for GIS (Gas Insulated Switchgear).
- Tolerances: The 2010 edition tightened the allowed deviation for impulse voltage generators from ±5% to ±3% for front time.