1. Standards & Certifications

Q1：What international standards do your power products comply with? Can they meet grid connection standards in my country?
A1：Our power equipment is designed based on IEC 60076 series standards. We can customize products to match GB, EN, GOST, ANSI/IEEE, AS/NZS, INMETRO, SABS, KEBS, SASO and other regional national standards. Please inform us of your project country and grid specification before order placement. We will carry out standard compliance assessment and supply relevant certification documents for your tender and grid approval.

Q2：Can you supply type test reports and third-party witnessed test documents? Is witnessed factory test available?
A2：Complete type test reports certified by CNAS, UL and KEMA are available for standard models. For high-voltage grid projects, witnessed factory tests (WTT) including temperature rise, short-circuit withstand and lightning impulse can be arranged upon schedule confirmation.

Q3：Are nameplates, engineering drawings, test reports and operation manuals available in English and other languages?
A3：English technical document package is included in standard delivery, covering nameplate drawing, general assembly drawing, FAT report, operation & maintenance manual and spare parts list. French, Spanish, Portuguese, Arabic, Russian and other language versions can be negotiated for large projects.

2. Technical Performance

Q4：What material is used for transformer windings, copper or aluminum? Can you put the winding material commitment into written contract?
A4：We offer both anaerobic copper winding and aluminum winding options as per your requirements. The winding material can be clearly stipulated in technical agreement and sales contract, together with supporting material inspection documents.

Q5：Can transformer loss, short-circuit impedance, temperature rise and insulation level strictly follow our datasheet? How do you handle excess loss after production?
A5：All key parameters can be customized according to owner technical specification and measured before shipment. If the factory FAT test fails to meet contracted loss indicators, the unit will not be delivered.

Q6：Are your transformers, switchgears and compact substations suitable for high temperature, high altitude, salt spray, high humidity or seismic regions?
A6：We provide environment-adapted reinforced design for harsh conditions: high-altitude temperature rise optimization, tropical heat dissipation, anti-corrosion coating up to C5M grade and seismic reinforcement. Please provide ambient temperature, altitude, salt spray class and seismic intensity for our design proposal.

Q7：Can your transformers handle harmonic loads from solar PV and wind power? Is harmonic suppression design available?
A7：Anti-harmonic transformers are customized for renewable energy projects. Optimized magnetic flux and temperature rise design enables stable operation under PV and wind farm harmonic working conditions.

Q8：What is the noise level of your transformers? Can it meet noise acceptance requirements for residential areas?
A8：Noise test follows IEC standards. Low-noise optimization is available for municipal and residential projects, and we can provide noise test curves for review.

Q9：Do your transformers satisfy grid requirements on lightning impulse and short-circuit withstand capability?
A9：Lightning impulse insulation level is selected matching equipment voltage class. Power transformers for main grid are equipped with short-circuit withstand design, with corresponding short-circuit type test reports available.

Q10：What is the design service life of your transformers? Does the design follow the 6℃ insulation aging rule?
A10：Distribution transformers have a 20-year design life, while power transformers are designed for 30 years. With regular proper maintenance and stable load, distribution transformers can reach 25–30 years and power transformers 35–50 years. Our insulation design follows the 6℃ aging law for oil-paper insulation.

Q11：Are you a genuine manufacturer of transformers, switchboards and compact substations?
A11：Yes. Founded in 1990, Hengfengshuai Electric owns nearly 30 years of manufacturing experience. Our senior engineers have more than 28 years of power equipment design experience. Our factory is located in Qingdao, China. Customers are warmly welcomed for factory audit and site inspection.

3. Customization, Dimensions, Lifting & Transportation

Q12：Can you produce non-standard electrical equipment? Can accessories, tap positions and external dimensions be customized according to the owner’s bill?
A12：Customization is supported for transformers, low & medium voltage switchboards, compact substations and mobile power substations. Accessories including on-load tap changers, bushings, temperature controllers, gas relays and pressure relief valves can be configured with owner-specified brands.

Q13：What are net weight, gross weight and overall dimensions of the equipment? Is oversize transport required? Can it fit site hoisting and inland road delivery?
A13：Weight and dimension sheet will be provided along with quotation. For large power transformers and heavy compact substations, we will evaluate hoisting load and road limits in advance and help you make oversize transportation plan.

Q14：What filling method do you use for transformer shipment: full oil, partial oil or nitrogen-filled without oil?
A14：Small distribution transformers are normally shipped full of oil. For large power transformers and long-distance ocean shipment, oil-drained nitrogen protection is adopted to avoid winding damage during transit. Shock recorder will be installed to monitor transportation vibration.

4. Production & Factory Acceptance Test (FAT)

Q15：What is your production lead time? How do you guarantee delivery schedule and handle delay risks?
A15：Production lead time depends on equipment specification and customization scope, which will be written into contract. We will send early warning once delivery delay risk occurs, and liability follows contract terms.

Q16：Can our team or third-party inspectors attend factory supervision and witness FAT?
A16：Customer or third-party supervision and FAT witnessing are accepted. We will coordinate production and test schedule in advance.

Q17：Are raw materials and spare parts traceable? Will core production processes be outsourced?
A17：Core components including iron cores, windings and transformer tanks are manufactured and controlled in-house. Batch traceability documents for critical raw materials can be supplied. Key manufacturing processes will not be outsourced.

5. Commercial Terms, Quotation, Payment & Customs Clearance

Q18：How long is quotation valid? Will price change when raw material cost rises?
A18：Standard quotation is valid for 15 days with fixed price within validity period. Re-quotation is needed after expiry. Extended validity up to 90 days (max 180 days) can be discussed for large EPC projects.

Q19：What payment terms do you accept? Is L/C acceptable? What is the minimum advance payment ratio?
A19：We accept T/T and irrevocable sight L/C. Advance payment percentage can be negotiated based on project scale and finally confirmed in contract.

Q20：Can you issue Certificate of Origin (CO) and other customs documents for tariff reduction?
A20：We can provide CO, FORM E and other FTA origin certificates to help customers apply for preferential tariff treatment.

6. Packaging, Logistics & Cargo Insurance

Q21：How is ocean export packaging handled? Can packaging resist salt spray and moisture? Are wooden crates marked with IPPC?
A21：Heavy equipment is packed with anti-rust, moisture-proof and shockproof treatment. Wooden export crates are marked with IPPC heat treatment stamp to meet destination port quarantine requirements.

Q22：What transportation options are available for your power equipment?
A22：Main transport modes include sea freight, heavy-lift bulk vessel, China-Europe Railway Express and trucking. Sea freight suits most countries; bulk vessels are used for oversized power equipment exceeding container limits. Railway and trucking are ideal for Central Asia and inland European markets.

Q23：What is the claim process if cargo damage occurs during transit?
A23：Take photos and survey evidence within 48 hours after arrival and file insurance notification. We provide full set of documents to support your claim. Liability judgment depends on insurance policy, shipping remarks and survey report.

7. Site SAT, Installation & Commissioning Service

Q24：Can your engineers go overseas to provide on-site installation guidance, commissioning and SAT acceptance support? What about service cost and response time?
A24：Overseas on-site technical service is available. Service fee, travel cost and arrival timeline will be quoted separately. Remote online technical guidance is also an option.

8. Warranty, After-sales & Spare Parts

Q25：What is your warranty period and coverage?
A25：Standard warranty period is 1 year. Extended warranty from 2 to 5 years can be agreed for projects. Warranty starts within 7 working days after customer receives and accepts goods. Warranty excludes damage caused by improper on-site operation, overload and external mechanical force.

Q26：Can you supply genuine spare parts after warranty expiration? What is spare parts delivery lead time?
A26：We guarantee long-term supply of original spare parts. We will offer spare part quotation and lead time to avoid spare part shortage during equipment service life.

Q27：What is your technical support response speed for equipment failure?
A27：Online technical support responds within 24 hours. For on-site emergency service, we will arrange engineer schedule after negotiation. After receiving your written fault notice, we give initial feedback within 24 hours. If site visit is required, our technicians can arrive within 7–15 working days subject to mutual agreement. Emergency response will be activated for critical faults threatening personnel or equipment safety.

Q28：How do you control product quality during manufacturing?
A28：Hengfengshuai Electric implements ISO quality management system and full SQA process control. All production steps follow standardized procedures. Many clients arrange third-party audits such as BV, SGS for factory inspection, and our products fully meet customer quality requirements.