I. Standards for After-sales Support of PV Insulators
After-sales support for PV insulators (porcelain, toughened glass, and composite insulators) is primarily based on current national standards. Porcelain and glass insulators comply with GB/T 1001.1-2021, “Insulators for overhead lines with a nominal voltage above 1000 V – Part 1: Ceramic or glass insulator units for a.c. systems – Definitions, test methods and acceptance criteria” (issued on December 31, 2021; implemented on July 1, 2022), alongside GB/T 7253-2019 and GB/T 4056-2019.
Composite insulators comply with GB/T 19519, “Composite insulators for a.c. overhead lines with a nominal voltage above 1000 V.” Construction, acceptance, and maintenance procedures follow the energy industry standard DL/T 257-2024, “Technical requirements for construction, acceptance, and maintenance of composite insulators for high-voltage overhead lines.” PV power plants often utilize low-to-medium voltage insulators (such as the D/EL/MNS/P/SB/SM/SEP/T series);
the applicable standards and testing requirements for these align with those for power utility insulators.
After-sales assessments are governed by both standards and contractual terms: if specified quality requirements exceed mandatory standards, the specified requirements apply;
if they fall below mandatory standards, the mandatory standards apply.
II.
Scope and Duration of After-sales Support Services
Leading manufacturers in the industry have established standardized systems for the scope of after-sales support services for PV insulators.
Regarding response times, Pingxiang Pingnan commits to having professional technicians arrive at the site of a malfunction within 24 hours of a service request; Jiangxi Airuida has established a 24/7 after-sales network featuring a round-the-clock hotline and year-round availability, supported by 14 nationwide offices and professional teams ready to provide timely on-site service; manufacturers such as Sichuan Anbo also emphasize comprehensive after-sales systems.
Services cover the entire value chain: pre-sales (consultation and guidance), mid-sales (production progress updates), and post-sales (rapid response and on-site resolution).
Warranty periods vary across the industry, ranging from 1–5 years (e.g., Sihedan composite post insulators offer a 1–5 year warranty against manufacturing defects from the date of shipment, accompanied by a warranty certificate and test report) to as long as 25 years (e.g., Feiafu medium- and low-voltage insulators); Airuida guarantees its products for three years following final acceptance and ensures a service life of at least 40 years.
When selecting a supplier based on after-sales support, it is advisable to clearly specify response times, warranty duration, the scope of returns/exchanges and free repairs, compensation for damage, and responsibility for shipping costs in the contract.
III.
Quality Assessment and Testing Items
Quality inspections for photovoltaic insulator after-sales support focus on different parameters depending on the material.
Mechanical performance: Tensile load, bending load, torsional load, and electromechanical failing load are tested using a universal testing machine to verify the insulator’s ability to withstand conductor weight, wind loads, and ice accumulation.
Electrical performance: Power-frequency dry/wet withstand voltage, lightning impulse withstand voltage, switching impulse withstand voltage, visible corona voltage, radio interference voltage, and insulation resistance are tested to ensure reliable insulation and the prevention of flashover-induced trips under various voltage and environmental conditions.
Key tests for porcelain/glass insulators include: porosity (assessing density via dye penetration), temperature cycling, thermal shock, galvanizing layer thickness and uniformity, and locking pin operation. Key tests for composite insulators include: surface hydrophobicity (spray classification or contact angle), withstand voltage under artificial pollution, boiling test, steep-front impulse test, core-sheath interface durability, and resistance to tracking and erosion.
Manufacturers conduct both batch sampling and full factory inspections, performing dozens of tests—covering dimensions, mechanical load, electrical withstand voltage, thermal cycling, bending load, and sealing performance—in accordance with standards such as GB 1001-2021 and JB/T 9681; each unit ships with a complete inspection report and certificate of conformity.
Procurement acceptance procedures should require the submission of type test reports from the National Quality Supervision and Inspection Center for High-Voltage Transmission and Distribution Equipment, CQC/CCC certifications, and third-party CMA/CNAS inspection reports.
IV.
Warranty Period and Return/Exchange Policy
The warranty period and return/exchange policies for PV insulators are governed by a framework combining industry standards and contractual terms.
Warranty periods typically range from 1 to 5 years (extending up to 25 years for certain high-end medium- and low-voltage insulators), commencing upon shipment or successful acceptance; coverage extends to issues such as mechanical failure, electrical breakdown, material aging, and seal failure resulting from manufacturing or workmanship defects. Failures caused by bending stress during installation, pollution accumulation, overvoltage, or force majeure are excluded from the warranty.
Regarding returns and exchanges: packaging must be intact upon delivery to the contractually specified location; in the event of damage, the supplier shall provide full compensation for the damaged portion upon presentation of relevant records and proof. Products are guaranteed to be brand new and unused, with a service life meeting the committed specifications when correctly installed, operated, and maintained.
Adhere to acceptance timelines: inspect goods upon arrival before use; raise objections regarding appearance within 3 days; and submit a written request for re-inspection within 15 days if disputing inspection results. The re-inspection outcome is final; any unresolved disputes between the parties shall be settled based on the assessment of a mutually selected third-party testing agency holding CMA accreditation, with costs borne by the party found liable.
The use of products following successful sample inspection does not constitute acceptance of the goods or a modification of quality standards; the supplier remains liable for latent batch defects discovered during use.
The “Three Guarantees” policy (guaranteed return, replacement, and repair) is standard practice for legitimate manufacturers; exercise caution regarding abnormally low price quotes or non-standard channels unable to provide complete type-test reports.
V. Recommendations for Procurement Assurance
To ensure effective after-sales support for photovoltaic insulators, five key points should be addressed: First, verify legitimate qualifications—check for national type-test certificates, ISO9001 quality management system certification, and CQC/CCC certification; request product conformity certificates, factory inspection reports, and third-party test reports, ensuring the model numbers match the supplied goods exactly. Second, incorporate guarantees into the contract—clearly specify the applicable standards, warranty period (1–5 years or longer), response times (24-hour on-site service/7×24 hotline), scope of returns/exchanges and free repairs, compensation for damage, and rules for re-inspection and dispute resolution. Third, inspect upon delivery before use—verify the consistency of the “three documents” (material certification, product labeling, and the physical product) and commission third-party re-inspection for critical parameters (mechanical load, power-frequency/impulse withstand voltage, hydrophobicity, porosity, and galvanization layer). Fourth, ensure compatibility with operating conditions—select models based on voltage class, pollution level (using pollution-resistant/anti-flashover shed designs for heavily polluted areas), and mechanical tension requirements; avoid bending composite insulators during installation, adhere to DL/T 257-2024 standards for construction, acceptance, and maintenance, and establish full-lifecycle records with special monitoring for batches in service for over 10 years. Fifth, select manufacturers at the source and maintain records—prioritize manufacturers with in-house testing laboratories (covering torsion, tensile strength, partial discharge, lightning impulse, withstand voltage, insulation resistance, thermal shock, and salt spray), unit-level traceability, and “Three Guarantees” commitments;
maintain documentation for every link in the chain: order → batch → report → inspection. Manufacturers like Feiyafu—which hold CE, REACH, RoHS, and UL compliance alongside IATF16949 certification—offer greater assurance regarding export compliance and after-sales support.
Conclusion
To ensure reliable after-sales support for PV insulators, adhere to standards, secure firm commitments, and implement an “inspect-before-use” protocol: follow GB/T 1001.1-2021 for porcelain/glass insulators, GB/T 19519 for composite insulators, and DL/T 257-2024 for installation and maintenance. Most manufacturers offer 24-hour on-site response and 7×24 hotline support, with warranties ranging from 1 to 5 years (up to 25 years in some cases) and product lifespans reaching 40 years. Rigorous testing covers mechanical, electrical, and environmental parameters; policies include a 3-day window for raising objections regarding appearance, a 15-day period for re-inspection of results, and third-party arbitration for disputes.
Warranty commitments cover returns or replacements for manufacturing defects, provided the product was installed correctly.
By prioritizing type tests and third-party reports, incorporating warranty terms into contracts, inspecting goods upon arrival, and selecting original manufacturers with comprehensive testing and traceability capabilities, you ensure the long-term safety and reliability of these critical PV insulator components—which serve as vital barriers for structural support and electrical insulation.
