Verify any claim · lenz.io
Claim analyzed
Science“Under ASTM D924 test conditions, the dielectric dissipation factor (power factor) of an in-service (aged) sample of Nynas Nytro 10XN transformer mineral oil at 70°C is greater than 0.01.”
Submitted by Clever Fox 9ec4
The conclusion
The claim is not supported by the available evidence. Reliable sources for NYTRO 10XN provide new-oil ASTM D924 values far below 0.01, while broader industry references only show that some badly degraded mineral oils can exceed 0.01 under certain conditions. That does not establish that an aged, in-service NYTRO 10XN sample at 70°C will be greater than 0.01.
Caveats
- Low confidence conclusion.
- No cited source provides a product-specific ASTM D924 measurement for aged or in-service NYTRO 10XN at 70°C.
- The claim treats a possible outcome for severely degraded mineral oils as a definite property of this named oil.
- A power factor above 0.01 is generally an abnormal or unsatisfactory condition, not something implied by the phrase “in-service (aged)” alone.
Get notified if new evidence updates this analysis
Create a free account to track this claim.
Sources
Sources used in the analysis
The product data sheet for NYTRO 10XN lists typical electrical characteristics for new oil. Under "Dielectric dissipation factor (tan δ), ASTM D924": at 25°C the typical value is given as 0.0001 and the limit value as 0.005; at 90°C the typical value is 0.002 and the limit value is 0.005. The table and notes describe properties of unused oil; no data are provided for in‑service or aged oil under ASTM D924 at 70°C.
“Standard Test Method for Dissipation Factor (or Power Factor) and Relative Permittivity (Dielectric Constant) of Electrical Insulating Liquids… This standard is issued under the fixed designation D924… 4.1 Dissipation Factor (or Power Factor)—This is a measure of the dielectric losses in an electrical insulating liquid when used in an alternating electric field and of the energy dissipated as heat… 4.1.1 The loss characteristic is commonly measured in terms of dissipation factor (tangent of the loss angle) or of power factor (sine of the loss angle) and may be expressed as a decimal value or as a percentage. For decimal values up to 0.05, dissipation factor and power factor values are equal to each other within about one part in one thousand.” (The method specifies how DF/PF is measured but does not give a specific value for Nynas Nytro 10XN or any particular oil at 70 °C.)
“The standard method that we follow in the laboratory is ASTM Method D924, which may quantify either power factor or dissipation factor of an insulating liquid… Liquid power factor (or a closely related measurement, dissipation factor, which is similarly interpreted) is calculated from direct measurement of these dielectric losses – the lower these losses, the better.” They note typical values are small and usually expressed as percent, e.g. “such as 0.001 or 0.10%,” which corresponds to 0.001 in decimal. The article explains that higher power factor/dissipation factor indicates deterioration but does not claim that all in‑service mineral oils, or NYTRO 10XN in particular, necessarily have DF/PF greater than 0.01 at 70 °C.
“Dielectric dissipation factor also known as tan delta or power factor offers direct assess[ment of] the quality and performance of insulating oils, making it a valuable indicator of insulation health… The dielectric dissipation factor quantifies the energy loss in an insulating material when subjected to an alternating electric field… Two primary standards are used globally for measuring DDF: ASTM D924 – Standard Test Method for Dissipation Factor and Relative Permittivity of Electrical Insulating Liquids… IEC 60247 – Measurement of relative permittivity, dielectric dissipation factor, and DC resistivity.” The article links increasing dissipation factor values with degradation due to moisture and oxidation, but it does not provide fixed numerical thresholds at 70 °C or specify that in‑service mineral oil must exceed 0.01 under ASTM D924.
Table 2 in the guideline gives “Suggested limits for continued use of in-service natural ester liquids (grouped by voltage class) (See IEEE Std C57.152).” The table includes the row: “Dissipation factor (power factor, ASTM D924, %, maximum 25°C 100°C See footnote c See footnote c.” These suggested limits are specific to natural ester transformer liquids and refer to 25 °C and 100 °C test temperatures; they do not state a specific numerical value or limit for 70 °C, nor do they cover mineral oils such as Nytro 10XN.
The distributor describes NYTRO 10XN as providing "maximum resistance to oil degradation" and "outstanding oxidation stability for a longer transformer life". It notes: "Nytro 10XN is an inhibited super grade that conforms to IEC 60296:2020 edition 5.0 and is Type A, classified as TVAI." The technical information given emphasizes conformity to IEC and ASTM specifications for new oil and does not claim or imply that in‑service (aged) NYTRO 10XN tested by ASTM D924 at 70 °C will have a dissipation factor greater than 0.01; typical dissipation factor values for fresh oil are much lower than 0.01.
The data sheet states: "Nytro 10XN is an inhibited super grade that conforms to both ASTM D3487 and IEC 60296 Edition 4.0, including the fulfilment of specific requirements for special applications." Under electrical properties it lists dielectric dissipation factor at elevated temperature for new oil (for example at 90 °C) with values such as "0.005" typical and "<0.001" guaranteed. These values are for unused oil and are less than 0.01. The sheet does not state that in‑service or aged oil under ASTM D924 at 70 °C will have a dissipation factor greater than 0.01; instead, the specified values for the product are below 0.01.
“ASTM D924: Power Factor test measures dielectric losses in an electrically-insulating liquid… Electrical properties include: dielectric strength, gassing tendency, and dielectric dissipation factor (or power factor). Chemical properties include: water content, acidity, and sludge content. Physical properties include: interfacial tension, viscosity, flash point, and pour point.” The description explains what ASTM D924 measures but does not specify particular values for dissipation factor in service, nor does it mention Nynas Nytro 10XN or a 70 °C test point.
Quoting ASTM D924: “4.1 Dissipation Factor (or Power Factor)—This is a measure of the dielectric losses in an electrical insulating liquid when used in an alternating electric field and of the energy dissipated as heat. A low dissipation factor or power factor indicates low ac dielectric losses… 4.1.1 The loss characteristic is commonly measured in terms of dissipation factor (tangent of the loss angle) or of power factor (sine of the loss angle) and may be expressed as a decimal value or as a percentage. For decimal values up to 0.05, dissipation factor and power factor values are equal to each other within about one part in one thousand. In general, since the dissipation factor or power factor of insulating oils in good condition have decimal values below 0.005, the two measurements (terms) may be considered interchangeable.” The summary restates the ASTM method and typical values for oils in good condition but provides no fixed requirement that in‑service NYTRO 10XN at 70 °C must exceed 0.01.
The tutorial on dielectric loss factor (dissipation factor, power factor) of transformer oils notes: "While new mineral oils typically have tan δ values below 0.5 % over the operating temperature range, in‑service oils may exhibit significantly higher values depending on the degree of ageing." It provides examples where oils in long‑service transformers show tan δ values of 1–2 % at 60–80 °C (0.01–0.02), particularly when oxidation and moisture are present.
The Nynas product page for NYTRO 10XN describes it as an inhibited super grade transformer oil meeting IEC 60296 and ASTM D3487. It highlights "extremely good electrical properties" and "outstanding oxidation stability" but does not specify expected dielectric dissipation factor (power factor) values for in‑service or aged oil. No information is provided about typical or limiting power factor values at 70 °C according to ASTM D924 for aged NYTRO 10XN.
Although this sheet is for NYTRO 10X rather than 10XN, it shows typical electrical properties for Nynas inhibited transformer oils. For dielectric dissipation factor at 90 °C (IEC 247), the table lists limit "0.005" and typical "<0.001". These values, measured on new oil, are significantly below 0.01, illustrating that Nynas mineral transformer oils are specified with low dissipation factor at elevated temperatures. The document does not describe any requirement that in‑service or aged oil when tested by ASTM D924 at 70 °C must be greater than 0.01; higher values are generally regarded as deterioration.
The hosted ASTM D924 PDF states: “1.1 This test method describes testing of new electrical insulating liquids as well as liquids in service or subsequent to service in cables, transformers, oil circuit breakers, and other electrical apparatus… 4.1 Dissipation Factor (or Power Factor)—This is a measure of the dielectric losses in an electrical insulating liquid when used in an alternating electric field and of the energy dissipated as heat… power factor (sine of the loss angle) and may be expressed as a decimal value or as a percentage. For decimal values up to 0.05, dissipation factor and power factor values are equal to each other within about one part in one thousand. In general, since the dissipation factor or power factor of insulating oils in good condition have decimal values below 0.005, the two measurements (terms) may be considered interchangeable.” This confirms typical values for oils ‘in good condition’ but does not prescribe that all in‑service oils at 70 °C (or NYTRO 10XN specifically) must exhibit values above 0.01.
In the electrical properties section, the sheet lists dielectric dissipation factor (power factor) values for NYTRO 10XN at elevated temperature. For example, under "Electrical" it shows: "D 924 0.3 <0.1" alongside breakdown voltage values at various conditions. These data are for new oil tested to ASTM D924, with dissipation factor values less than 0.1% (0.001) or similar, not greater than 1% (0.01). The sheet does not mention 70 °C specifically or address aged/in‑service samples. There is no statement that the dissipation factor of in‑service NYTRO 10XN at 70 °C is expected to be greater than 0.01; rather, the example values for unused product are much lower.
In power transformer maintenance practice, utilities and testing laboratories commonly apply guidance where mineral transformer oil power factor (ASTM D924) for in‑service units is expected to remain below about 0.5 % at 25 °C and below roughly 1 % at 60–70 °C in healthy equipment. Values greater than 1 % (tan δ > 0.01) at elevated temperature are widely interpreted as evidence of significant oil ageing or contamination rather than a normal characteristic of the oil brand. These thresholds are general for mineral oils and are not specific to NYTRO 10XN, but they frame how a value above 0.01 at 70 °C would usually be interpreted.
The presentation describes NYTRO 10XN as "an inhibited super grade insulating oil developed for use in heavy duty electrical equipment like transformers" and notes: "It also has high dielectric strength when stored and handled correctly." While it mentions that the oil has very good electrical properties, it does not give specific dissipation factor values at 70 °C for in‑service oil. Nothing in the slides suggests that an aged sample tested under ASTM D924 at 70 °C will have a dissipation factor greater than 0.01; the emphasis is on low-loss, high‑quality insulating performance.
The NETA Maintenance Testing Specifications discuss evaluating the dielectric dissipation factor (power factor) of insulating oil. The guidance notes that lower power factor values indicate better insulation quality and that increasing power factor with time is a sign of contamination or aging. Typical acceptance criteria keep oil power factor well below 1% at the test temperature; values at or above 1% (0.01) are generally considered unsatisfactory and indicate the need for corrective actions. The document does not state that in‑service oil should have a power factor greater than 0.01; rather, 0.01 is treated as a high or unacceptable value.
In a user discussion about diagnostic values, one contributor claims that "for in‑service mineral oil like Nynas Nytro 10XN, when you run ASTM D924 at 70°C you can easily see power factor values over 1% (0.01), especially in older transformers" and suggests that this is "normal" for aged units. This comment is anecdotal and not supported by any cited standard or manufacturer specification, but it presents an argument that in‑service samples may show dissipation factor over 0.01 at 70 °C in practice.
What do you think of the claim?
Your challenge will appear immediately.
Challenge submitted!
Continue your research
Verify a related claim next.
Expert review
3 specialized AI experts evaluated the evidence and arguments.
Expert 1 — The Logic Examiner
The supporting evidence (notably Source 10) shows that some in-service mineral oils can reach tan δ ≈ 1–2% at 60–80°C under certain ageing/contamination conditions, while Sources 15 and 17 frame >1% as a possible but abnormal/unsatisfactory condition; none of the sources provides product-specific ASTM D924 data for an aged/in-service NYTRO 10XN sample at exactly 70°C, so the inference from “can occur” to “is (in this case) greater than 0.01” is not logically warranted. Therefore the claim, stated as a definite property of an in-service (aged) sample under ASTM D924 at 70°C, overgeneralizes beyond the evidence and is not established as true.
Expert 2 — The Context Analyst
The claim asserts a specific numerical outcome (>0.01 at 70°C) for an unspecified “in-service (aged)” Nytro 10XN sample, but the evidence only shows (a) new-oil specs are far below 0.01 (Sources 1, 7, 14) and (b) some in-service mineral oils can reach ~0.01–0.02 at 60–80°C when notably oxidized/moist (Source 10) while guidance treats ≥0.01 as an abnormal/unsatisfactory condition rather than a typical aged-oil property (Source 17). With full context, “aged/in-service” does not imply the oil will exceed 0.01 under ASTM D924 at 70°C—only that it might if sufficiently degraded—so the overall impression is misleading and effectively false as stated.
Expert 3 — The Source Auditor
The most authoritative sources here are Source 1 (Nynas AB official product data sheet, high authority) and Source 7 (Nynas distributor PDS), both of which provide only new-oil ASTM D924 values well below 0.01 (limits of 0.005 at 90°C) and contain no data for in-service or aged oil at 70°C. Source 10 (CIGRÉ tutorial reprint, moderate authority) offers general illustrative examples of in-service mineral oils reaching 1–2% tan δ at 60–80°C but does not specifically reference Nytro 10XN or ASTM D924 conditions. Source 17 (NETA, moderate authority) frames ≥0.01 as an unsatisfactory threshold requiring corrective action, not as an expected characteristic of aged oil. Source 18 (EnergyStandard forum, very low authority) is anecdotal and uncited. The claim asserts a specific numerical outcome (>0.01) for a specific product (Nytro 10XN) under specific conditions (ASTM D924, 70°C, aged sample), but no reliable, independent source confirms this specific combination; the supporting sources are either general, illustrative, or low-authority, while higher-authority sources either refute or fail to support the claim, making it unsubstantiated as stated.
Expert summary
The arguments
Two AI advocates debated this claim using the research gathered.
Argument for
Source 10, a CIGRÉ tutorial, directly supports the claim by documenting that in-service oils in long-service transformers exhibit tan δ values of 1–2% (0.01–0.02) at 60–80°C when oxidation and moisture are present—conditions typical of aged mineral oil like Nytro 10XN. This is corroborated by Source 15, which confirms that industry practice treats values greater than 1% (>0.01) at 60–70°C as evidence of significant oil ageing, and Source 17 (NETA) acknowledges that in-service oils can reach or exceed 0.01, treating it as a threshold for corrective action—all of which establishes that an aged Nytro 10XN sample tested under ASTM D924 at 70°C can and does exceed 0.01 in real-world service conditions.
The Proponent commits a scope-and-method fallacy by treating CIGRÉ's illustrative cases of “in‑service oils” at 60–80 °C under unspecified measurement conditions as if they were ASTM D924 results for the specific product NYTRO 10XN at 70 °C, despite the only product-specific D924 evidence being new-oil values and limits far below 0.01 and no in-service 70 °C datapoint at all (Source 10, CIGRÉ tutorial reprint; Source 1, Nynas AB; Source 7, InTyler Fimaco). Moreover, Source 15 is explicitly non-product-specific background and Source 17 frames ≥0.01 as an unsatisfactory trigger for corrective action rather than an expected property of “an in-service (aged) sample,” so the Proponent's leap from “can occur when contaminated” to “is greater than 0.01” is an unsupported generalization (Source 15, LLM Background Knowledge; Source 17, NETA).
Argument against
The motion asserts a specific numerical outcome (>0.01 at 70°C) for an aged in-service NYTRO 10XN sample under ASTM D924, but the most authoritative manufacturer documentation provides only new-oil D924 values and limits that are far below 0.01 (e.g., limit 0.005 at 90°C) and gives no 70°C in-service data at all, so the claim is unsupported and contradicted by the product's specified low-loss performance (Source 1, Nynas AB; Source 7, InTyler Fimaco). Moreover, industry guidance treats ~1% (0.01) as an unsatisfactory/high condition rather than an expected characteristic of in-service oil, and the only “support” for “easily over 0.01” is an uncited anecdotal forum post, which is weaker than the standards-based framing that oils “in good condition” are typically <0.005 (Source 17, NETA; Source 13, ASTM D924 host; Source 18, EnergyStandard forum).
The Opponent commits a category error by conflating new-oil specifications with in-service performance limits: Source 1 and Source 7 explicitly describe unused oil properties, and neither document claims that aged oil cannot exceed 0.01—their silence on in-service values at 70°C is not a refutation. Source 10, a CIGRÉ tutorial, directly documents empirical tan δ values of 1–2% (0.01–0.02) at 60–80°C for in-service mineral oils with oxidation and moisture, and Source 17 (NETA) itself acknowledges that in-service oils can reach or exceed 0.01—the Opponent's own cited sources thus confirm that exceeding this threshold is a real, documented outcome for aged mineral transformer oil under ASTM D924 conditions.