Know which statement is actually confirmed
OSTL states routine tests per IS 1180 / IS 2026. That is the confirmed company statement used on this website. It does not, by itself, verify every individual test arrangement, test value, laboratory accreditation, type-test facility or special-test capability. Request the proposed inspection and test plan for the product you are buying.
Standards distinguish routine, type and special tests. The classification and applicability depend on the product, applicable standard and agreed scope. A buyer should not assume that a general list from a guide is automatically included in every quotation.
Typical topics in a transformer test discussion
| Topic | What the buyer is trying to understand |
|---|---|
| Winding resistance | How winding-resistance measurements are recorded and related to the test conditions. |
| Voltage ratio and phase relationship | How the winding ratio and connection/phase relationship are checked against the specified design. |
| No-load loss and current | How excitation-related measurements are documented and compared with the agreed requirements. |
| Load loss and impedance | How the specified load-loss and impedance requirements are assessed, including reference conditions. |
| Dielectric testing | Which dielectric tests and levels apply under the product standard and agreed insulation specification. |
| Other inspections or tests | Which additional checks, type/special tests, finish inspections or witness requirements are separately applicable and agreed. |
Questions to settle before the order
- Which product standard and edition apply, and why are they appropriate to this transformer?
- Which tests are included as routine, and which require a separate agreement?
- What guaranteed values, reference conditions, tolerances and acceptance criteria will be used?
- Who performs each test, what documentation is supplied, and what traceability identifies the tested unit?
- Are buyer witnessing, third-party inspection or additional test requirements included, excluded or separately quoted?
- When will the proposed test schedule and report format be reviewed?
Read a report in context
A useful record should let the buyer connect the tested transformer to its identification, approved requirements and relevant test conditions. Do not compare isolated numbers from two reports if their reference conditions or specifications differ. Your project engineer should assess whether the agreed acceptance requirements have been met.
This page does not publish pass limits, test voltages, measured losses, calibration claims or certificates for an OSTL model. Such details must come from the confirmed project documents and actual test records.
Standards context and further reading
The IEC 60076-1 general standard overview provides international context for transformer specifications and testing. It is not a claim of OSTL certification to IEC 60076. For procurement, use the applicable authorised standard documents and the project engineer’s agreed requirements.
For OSTL’s confirmed company quality references, see Quality & Testing. Use the quotation checklist to state your inspection and documentation requirements before ordering.