Question 1

What does the Oil Condition Classifier do?

Accepted Answer

It scores an insulating liquid against the table that governs it at the lifecycle state you select — in service, as received, or after filling in new equipment. In service returns Good/Fair/Poor under IEC 60422, IEC 61203 or IEC 62975, Condition I/II/III under IEEE C57.166-2026 for main-tank liquid (Class I/II/III under the superseded IEEE C57.106-2015, still offered for mineral oil), or Group 1/2 under IEC 60944; the two acceptance states return a meets-limit / exceeds-limit comparison against the standard’s own acceptance table for that state. It covers the condition of the liquid; the Duval and IEC 60599 tools answer the separate question of whether a fault is active.

Question 2

Why does the parameter list change when I switch standard?

Accepted Answer

Because the parameters are not interchangeable. IEC paths use breakdown voltage per IEC 60156 with a 2.5 mm gap and dissipation factor at 90 °C. IEEE and ASTM paths use electrode-specific breakdown voltage (ASTM D1816 at 1 mm and 2 mm, D877, D3300 impulse) and dissipation factor at 25 °C and 100 °C. Scoring a D1816 result against an IEC 60156 limit — or vice versa — would be wrong, so the tool only ever asks for what the selected standard publishes — and selecting a lifecycle state other than in-service changes that list again, to whatever that standard’s own acceptance table requires.

Question 3

What is the difference between the IEC/IEEE and ASTM modes?

Accepted Answer

IEC and IEEE publish in-service condition assessments. ASTM publishes no in-service condition-classification standard for insulating liquids — D3487, D6871 and D4652 are acceptance specifications for unused liquid as delivered. The IEC and IEEE paths also reach the two states before service — as received, and, where the standard publishes a table for it, after filling before energisation — and that is what the lifecycle state selects. So the ASTM mode is a within-spec / out-of-spec comparison against the delivery specification, it is labelled as such, and it ignores rated voltage and equipment type entirely.

Question 4

Can I check a delivery against IEC 60296, IEC 61099, IEC 62770 or IEC 60836?

Accepted Answer

Yes. Select the fluid, the IEC standard family, and the lifecycle state “As received”. For mineral oil, also pick the product type (IEC 60296 Type A or B, transformer or low-temperature switchgear oil). The tool then compares against the delivery specification instead of the in-service condition bands.

Question 5

How is the overall verdict calculated?

Accepted Answer

Strict worst-of: the single worst parameter band across everything entered, with no weighting between parameters. Rows the standard cannot classify, and TriboTech operational bands, are shown but excluded from the verdict. The IEEE path for main-tank liquid in service is the exception. IEEE C57.166-2026 publishes one continued-use limit per parameter, and §8.2 sorts the liquid into three groups over the whole result set: Condition I when every limit scored is met, Condition II when only breakdown voltage and/or water fail (reconditioning territory), Condition III when anything else fails. For Condition III, §8.2 names interfacial tension, acid and power factor. The word “only”, and placing a failure on a row it does not name (such as colour or fire point) in Condition III, are TriboTech’s reading, and the result says so when that is the basis. The superseded IEEE C57.106-2015 path applies the same rule as Class I/II/III.

Question 6

Where do the limits come from?

Accepted Answer

From a versioned data file in which every single limit carries its standard, table, row and page number. A build test fails if any value lacks that provenance. Each parameter result shows the citation of the limit it was judged against, so any value can be checked against the standard itself. Where a standard publishes no limit — IEEE C57.166-2026 Table 3 prints no breakdown-voltage value for silicone liquid in new equipment — the tool says so instead of substituting a number.

Question 7

Can I treat the result as a diagnosis?

Accepted Answer

No, and the standards say so themselves. IEC 60422:2024 (Clause 9.4.1) states that classification and corrective action "should only be taken after due consideration of the results of all tests, the age and type of equipment", and that "the trend of such results over a period of time is considered essential information when arriving at a final decision". IEEE C57.166-2026 (§8.2) adds that "no single test can be used as the sole criterion to estimate the condition of the transformer", and that it "is not intended that liquids be removed from service when a single property limit is exceeded". This page does the standards comparison — one sample against one table. A defensible assessment also weighs trend and rate of change, the parameters against one another and against the DGA, the unit's age, design, duty and history, and its criticality if it fails. That is consulting work, and it is what TriboTech does.

Question 8

Is my data sent to TriboTech?

Accepted Answer

No. All computation runs in your browser. The page does not log, transmit, or persist any measured value.

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Oil Condition Classifier

Further reading

Breakdown Voltage: Why the Method — Not the Oil — Defines the Number

Why Your ppm Water Number Lies — and What %RS Tells You Instead

Interfacial Tension: The Most Underrated Test in Your Transformer Oil Programme

Dissipation Factor: The Oil Sample's Tan Delta Is Not the Transformer's

Which Table Applies? Acceptance, After Filling, and In-Service Limits for Insulating Fluids