Lightning Impulse Test
A high-voltage test simulating lightning surges to verify transformer insulation withstands transient overvoltages.
The lightning impulse test applies a 1.2/50 microsecond impulse wave to verify insulation withstands lightning/switching transients. Per IEC 60076-3 or IEEE C57.
Level determined by BIL requirements. Standard sequence: one at 50-70% (calibrating), two at 100%. Pass: no waveform change between impulses.
Mandatory for all transformers, most definitive insulation integrity verification.
QDTB performs full lightning impulse testing on every transformer as routine factory acceptance, with complete oscillographic records.
Related Products
Related Terms
BIL (Basic Impulse Level)
The ability of transformer insulation to withstand high-voltage surges from lightning or switching, measured in kV peak.
Dielectric Strength
The maximum electric field an insulating material can withstand before breakdown, measured in kV/mm.
Insulation Class (A/E/B/F/H)
Standardized temperature ratings for transformer insulation materials defining maximum operating temperatures.
IEC 60076
The IEC standard series defining requirements for power transformers, the global reference standard.
More Terms Starting with “L”
Load Tap Changer (LTC)
A mechanism allowing transformer tap ratio changes while energized and under load for real-time voltage regulation.
Leakage Reactance
Reactance from magnetic flux not linking both windings, a major component of transformer impedance.
Loss Evaluation
A financial methodology assigning monetary value to transformer losses for optimal lifetime economic selection.
Lightning Arrester (Surge Arrester)
A protective device diverting high-voltage surges from lightning and switching to ground, safeguarding transformer insulation.
More in “Insulation & Testing”
BIL (Basic Impulse Level)
The ability of transformer insulation to withstand high-voltage surges from lightning or switching, measured in kV peak.
Dielectric Strength
The maximum electric field an insulating material can withstand before breakdown, measured in kV/mm.
Insulation Class (A/E/B/F/H)
Standardized temperature ratings for transformer insulation materials defining maximum operating temperatures.
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