Accreditation — CNAS L7721, ISO/IEC 17025:2017 and ILAC-MRA | YONGU High Voltage Electrical Testing Center

Status

Accreditation held

One competence standard, one certificate, one registration number. The laboratory does not claim accreditation it does not hold.

ISO/IEC 17025:2017 — Testing

Competence of the testing laboratory, assessed by the China National Accreditation Service for Conformity Assessment (CNAS) under CNAS-CL01.

Accredited entity	High Voltage Electrical Testing Center of YONGGU Group Co., Ltd.
Registration no.	CNAS L7721
Effective date	27 May 2024
Expiry date	26 May 2030
Activity	Testing
Scope	~200 test items across ~80 national standards

The accredited scope is defined by the schedule attached to the certificate, which bears the same registration number and forms part of the certificate. The full schedule is available on request.

ILAC-MRA mutual recognition

CNAS is a signatory of the ILAC Mutual Recognition Arrangement and of the APAC Mutual Recognition Arrangement. Reports covering items inside the accredited scope carry the accreditation mark and are recognised by the accreditation bodies and regulators of the other signatory economies.

For an overseas buyer, a customs officer or a utility engineer, this is the mechanism that makes a Chinese test report readable without a second opinion — which is the whole reason the report is worth commissioning.

How to verify one of our reports

Where we must be honest

What is not accredited

Buyers who receive a certificate without limits start asking questions later. These are the limits of this laboratory, stated in advance.

CMA qualification — not held

The laboratory is not a CMA-qualified inspection and testing body (检验检测机构资质认定). For domestic regulatory or statutory purposes that require a CMA-marked report, this laboratory cannot issue one and you should use a CMA-qualified body.

ISO/IEC 17020 — not held

The laboratory is not an accredited inspection body. It does not issue independent pre-shipment inspection certificates or third-party conformity attestations. Witnessing a test at a customer's works is offered as engineering support on the samples, not as inspection.

ISO/IEC 17043 — not held

The laboratory is not an accredited proficiency testing provider and does not organise inter-laboratory comparison programmes for third parties.

Calibration — not accredited

The certificate covers testing activity. The laboratory maintains its own instrument traceability but does not hold calibration accreditation, and does not issue accredited calibration certificates.

Tests outside the schedule

Investigative tests, factory-defined methods agreed with a customer, and anything not listed in the schedule attached to CNAS L7721 are carried out under the same quality system but are not accredited results. The report says so on the page concerned.

It is the group's own laboratory

The centre is the testing laboratory of YONGGU Group Co., Ltd., a manufacturer. It is not an independent third-party body, and no claim in this website should be read as one. See the impartiality statement below.

Scope

Accredited scope at a glance

A summary of the product families and standards covered — transmission and distribution materials as well as high- and low-voltage electrical products. The full schedule runs to many pages and is available on request, or from the CNAS register.

Product family	Standards in scope	Accredited test items
Power cables & wires	IEC 60502, IEC 60227, IEC 61089, GB/T 12706, GB/T 5023	Conductor DC resistance, insulation thickness, AC withstand, partial discharge, ageing
Power fittings	IEC 61284, GB/T 2314, GB/T 14315, GB/T 9327, DL/T 2340, DL/T 2341	Failing load, slip load, galvanising mass, hardness, dimensions, DC resistance
Cable accessories 1–35 kV	IEC 60502, GB/T 12706, GB/T 9327	Power-frequency withstand, partial discharge, thermal cycling, heat ageing
Insulators & arresters	IEC 61109, IEC 60099-4, GB/T 19519, GB/T 11032	Withstand voltage, lightning impulse, mechanical failing load, ageing
HV switchgear & distribution apparatus	IEC 62271-1, IEC 62271-100, IEC 62271-102, IEC 62271-103, IEC 62271-200, IEC 60282-1, GB/T 11022, GB/T 1984, GB/T 1985, GB/T 3906, GB/T 15166	Withstand voltage, lightning impulse, temperature rise, mechanical operation, short-time current, over-current
LV electrical products	IEC 61439-1, IEC 60947-1, IEC 60947-2, IEC 60529, GB/T 7251.1, GB/T 14048.1, GB/T 14048.2	Withstand voltage, temperature rise, mechanical operation, over-current, enclosure and IP checks
Copper & aluminium products	IEC 61089, GB/T 3190, GB/T 5231, GB/T 5585	Composition, tensile strength, elongation, DC resistivity, dimensional tolerance

Standard numbers are listed as the editions currently in the schedule. The accredited schedule itself lists Chinese national (GB) standards; equivalent IEC and EN methods are performed under the same quality system, and a result is only presented as accredited where the method concerned is inside the schedule. Where a customer specifies a different edition or an IEC equivalent, this is confirmed at the test plan stage.

Interpreting the mark

What an accredited result means

The test method and the laboratory's competence for that method have been assessed by an accreditation body
The report may carry the accreditation mark and the registration number CNAS L7721
The result is recognised under the ILAC and APAC mutual recognition arrangements
Instruments used are traceable and their calibration records are retained with the raw data
Accreditation does not mean a product conforms — it means the test was performed competently. The conclusion in the report applies to the sample tested

Authorised signatories

Reports are signed by engineers listed in the accreditation schedule. The signature, the report number and the online verification record must all agree for a report to be valid.

A report without a report number, or one whose number cannot be found, is not ours. Please send a scan to [email protected] and we will confirm in writing.

Request the list of signatories

Impartiality

Our position on independence, stated plainly

A laboratory that tests its own group's products is not an independent third party, whatever else it may claim. This laboratory does not claim to be one, and it would be misleading to describe it otherwise.

What it does claim is narrower and verifiable: that the tests are performed and reported in accordance with ISO/IEC 17025:2017; that results are recorded as measured; and that no result is altered, withheld or re-issued to a different value for commercial reasons.

The safeguards that support that claim are structural rather than promises:

The laboratory operates its own quality system and is audited by CNAS on a fixed cycle, independently of the sales function
Every report is technically reviewed before release, and the review covers the raw data, not just the summary
Test engineers are appointed on technical competence and are not assessed on the pass rate of the samples they test
A non-conforming result is issued as a non-conforming result; it cannot be withdrawn at the request of a customer or a group company
Complaints and appeals are reviewed by the technical review function, not by the commercial team

If your project requires an independent third-party report, this laboratory is the wrong instrument for that requirement, and we would rather tell you now than in a tender. Where a buyer or a regulator insists on a third-party body, use an accredited laboratory or inspection body that is not part of the supplier's group. We will assist with the technical documentation either way.

Accreditation & certificates