BUYER'S SHORT ANSWER
Compare the tested assembly with the offered lineup, not just the rated-voltage line. Buyers should check the complete IAC designation, LSC category, partition class, short-circuit ratings, component changes and any project interfaces not covered by the type-test report.
Use this note alongside the governing standards, applicable certificates and the responsible engineer's approval.
Do not start with a claim of equivalence
GB/T 3906-2020 is the current Chinese national standard entry for AC metal-enclosed switchgear from 3.6 kV to 40.5 kV. IEC 62271-200:2021 covers AC metal-enclosed assemblies above 1 kV and up to 52 kV, with Amendment 1 published in 2024. The titles overlap, but a procurement review still has to check edition, scope and project options.
The practical task is to map each tender requirement to a report page, drawing or manufacturer declaration. Where the report is silent, mark the item “not evidenced”; do not change that wording to “failed”.
Read the classification string in full
An internal arc classification is meaningful only with its complete designation: accessibility type, tested sides, arc current and duration. A brochure phrase such as “arc-resistant” is not a substitute. Confirm the test arrangement, room simulation, panel width and pressure-release route, especially when the offered lineup has different end panels or cable entries.
Service continuity category and partition class should also be stated explicitly. They describe how the assembly is constructed and what remains energised during access. They cannot be recovered from the rated-voltage line on a test summary.
The tested assembly is a configuration, not a logo
Circuit breaker type, busbar size, compartment geometry, shutters, cable terminations, protection transformers and ventilation paths can affect applicability. Ask for a schedule that identifies which components in the offered panel are identical to the tested arrangement and which have changed.
A manufacturer may have a sound technical basis for a variation. The buyer needs that basis in writing—supported by the applicable design rule, calculation or additional test—not an unqualified statement that all models are covered.
Separate standard evidence from project interfaces
The standard report may not answer cable test access, SCADA protocol, auxiliary supply, interlocking with upstream equipment, arc-duct routing or local utility labelling. Those are project interfaces. Place them in a separate schedule so that missing project data is not confused with a failed type test.
For outdoor or containerised installations, add ambient temperature, altitude, humidity, pollution, condensation control and enclosure interfaces. The indoor switchgear report remains evidence for the assembly; it is not evidence for the whole building.
A concise request to the manufacturer
Request one evidence matrix with four columns: requirement, offered value, evidence reference and deviation or action. Include the full IAC and LSC designations, short-time withstand ratings, dielectric levels, main component list and report-to-offer comparison.
This format gives the project engineer something that can be reviewed, revised and attached to the purchase specification.
QUESTIONS BUYERS ASK
Frequently asked questions
Is an “arc-resistant” brochure statement enough?
No. The buyer needs the complete internal arc classification, including accessibility type, tested sides, arc current and duration, plus confirmation that the offered arrangement is represented.
Does an indoor switchgear report cover the complete E-House?
No. It supports the switchgear assembly only. The building, ventilation, cable, protection, auxiliary and site interfaces require separate project evidence.
Reference publications
Always confirm the edition named in the contract and obtain authorised copies of the applicable standards.
China National Standard Information — GB/T 3906-2020 ↗IEC Webstore — IEC 62271-200:2021 ↗IEC Webstore — Amendment 1:2024 ↗