Quality
How we prove a transformer will last
A transformer is a 25-year commitment. This page sets out what we test, on what equipment, to which standards, and what evidence you can ask for.
Impulse test capability
We operate two lightning impulse generator systems. Products rated up to 220 kV are tested on a 1200 kV system. Products above 220 kV are tested on a 4800 kV system. Against IEC 60071-1 insulation levels, the 4800 kV system covers the 500 kV class with substantial margin.
Partial discharge measurement
PD background is measured and recorded per facility. At our dry-type plant in Hai'an the background is ≤1 pC. At our oil-immersed plant in Harbin it is ≤10 pC. Both are well below the limits our customers typically specify.
Accredited laboratory
Our testing centre holds CNAS accreditation, registration number L5393. CNAS is the Chinese national accreditation body and a signatory to the ILAC mutual recognition arrangement. Type test reports from an accredited laboratory are accepted by utilities and owner's engineers in our target markets.
What we test
| Routine tests | ratio, polarity, winding resistance, no-load loss, load loss, impedance, applied voltage, induced voltage, insulation resistance, oil tests. |
|---|---|
| Type tests | temperature rise, lightning impulse, partial discharge, noise, short-circuit withstand (witnessed at an external laboratory). |
| Special tests | as specified by the customer. |
Standards we build to
IEC 60076 series for power transformers. IEC 60076-11 for dry-type. IEC 60270 for partial discharge measurement. IEC 60071-1 for insulation co-ordination. IEEE C57 series where customers specify it. AS/NZS 60076 for Australia and New Zealand. GB standards for the domestic market.
Evidence you can request
Routine test reports for your unit. Type test reports for the model family. CNAS accreditation certificate and scope. Calibration certificates for our impulse and PD measurement systems. Material certificates on request.
If you are preparing a power transformer factory audit checklist, these are the items worth requesting, and a supplier who can produce them without delay is usually a supplier whose documentation is under control.
Documentation at handover
Every unit ships with a test report, outline drawing, nameplate data, oil test results where applicable, and installation and commissioning instructions in English.