See More Than 50/60 Hz Testing Alone
Routine power factor (PF) or dissipation factor (DF) testing at 50/60 Hz remains essential, but it does not always show the full picture. 1 Hz testing helps reveal developing insulation problems earlier, strengthens confidence in transformer insulation assessment, and supports better decisions across critical high-voltage assets.
Reduce Risk Before Return to Service
Reveal developing insulation problems earlier so teams can act before hidden issues put the asset, the project, or the wider network at risk.
Stronger Confidence in Asset Condition
Validate routine 50/60 Hz results with greater sensitivity and support more reliable maintenance and energization decisions.
See More Than Line-Frequency Testing Alone
Use 1 Hz testing to make moisture, contamination, and ageing effects easier to detect, enabling clearer decision-making from test results.
Why Use 1 Hz Testing for Insulation Assessment
1 Hz testing helps turn routine PF/DF results into stronger decisions. It gives teams the added sensitivity needed to confirm asset condition with greater confidence, prioritize maintenance more effectively, and reduce uncertainty before critical equipment is returned to service.
With solutions for routine testing, advanced diagnostics, and wider transformer and substation workflows, Megger helps you apply 1 Hz testing in the way that best fits your needs.
What 1 Hz Testing Reveals About Insulation Condition
50/60 Hz testing provides the baseline.
1 Hz adds sensitivity where developing insulation problems are easier to detect.
Changing the test frequency does not replace established testing methods. It strengthens the information available for asset decisions.
1 Hz Testing Equipment And Solutions
Choose the right solution for your testing approach, application, and level of diagnostic depth.
DELTA4000
Bring 1 Hz testing into routine PF/DF workflows and validate insulation condition with greater confidence using the same connection and a familiar test process.
IDAX
Go beyond routine PF/DF testing with deeper dielectric frequency response insight into moisture, ageing, and transformer insulation condition.
TRAX + TDX
Add 1 Hz insulation diagnostics to broader transformer and substation testing workflows in one flexible platform built for practical field use.
Need More Confidence In Insulation Assessment?
If routine PF/DF testing leaves uncertainty around insulation condition, 1 Hz testing can help you validate results with greater confidence and support stronger maintenance and energization decisions.
1 Hz Testing Resources and Case Studies
Explore resources that show how 1 Hz testing strengthens insulation assessment, reveals developing issues earlier, and supports more confident asset decisions.
Why Lower-Frequency Testing Reveals More
Understand why 1 Hz testing adds sensitivity beyond routine 50/60 Hz assessment and helps reveal developing insulation problems earlier.
1 and 500 Hz Analysis on bushings - Identifying aging and installation issues in an HV bushing
After completing on-load tap changer (OLTC) maintenance on this 1969-vintage transformer, the utility owner followed with electrical tests.
Bushing Diagnostics Case Breakdown
See how frequency-based diagnostics supported a more confident decision in a real 230 kV bushing assessment.
FAQs About 1 Hz Testing Solutions
1 Hz testing is a lower-frequency power factor and dissipation factor insulation test used to assess the condition of high-voltage assets such as transformers and bushings. It is used when teams need greater sensitivity than routine 50/60 Hz testing alone can provide, particularly when validating insulation condition, investigating suspected degradation, or supporting more confident maintenance and energization decisions.
Routine 50/60 Hz PF/DF testing remains essential, but it does not always show the full picture. Results may stay within acceptable limits even when moisture, contamination, or ageing are already affecting insulation condition. 1 Hz testing adds sensitivity where those changes are easier to detect, helping teams confirm whether a routine result is genuinely reassuring.
1 Hz testing improves confidence by giving teams more meaningful insight than line-frequency testing alone. By comparing 50/60 Hz and 1 Hz results, engineers and asset managers can better distinguish between insulation that is genuinely stable and insulation that may be degrading. That stronger evidence supports clearer maintenance, repair, and energization decisions.
1 Hz PF measurement can be performed with a dedicated dielectric frequency response instrument, such as IDAX, or with the same equipment used for 10 kV PF/DF testing, including DELTA4000, or with multifunction solutions, such as TRAX + TDX. The right choice depends on whether you need routine insulation assessment, deeper diagnostics, or 1 Hz capability as part of a wider transformer and substation testing workflow.
Not Sure Which 1 Hz Solution Fits Your Testing Needs?
From routine PF/DF validation to deeper insulation diagnostics and broader transformer testing workflows, Megger can help you choose the right 1 Hz solution for your application.
