Chapter 85 covers electrical machinery and equipment and parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers, and parts and accessories of such articles. This chapter is the core chapter for electrical and electronic goods in the HS classification, involving a wide range of fields such as power generation, transformation, energy storage, electrical equipment, communications, and consumer electronics. Transformers, as key equipment for power transmission and conversion, are classified in this chapter. Heading 8504 includes electrical transformers, static converters (such as rectifiers and inverters), and inductors. Transformers are used to change AC voltage and current, static converters are used to change current type or frequency, and inductors are used for energy storage and filtering in circuits. This heading is further subdivided by power capacity, use, etc. 850434 specifically refers to transformers with a capacity exceeding 500 kVA. The first 2 digits "85" represent Chapter 85 (electrical machinery and equipment and parts thereof). The 3rd-4th digits "04" represent heading 8504 (electrical transformers, static converters, and inductors). The 5th-6th digits "34" represent subheading 850434, namely liquid dielectric transformers with a capacity exceeding 500 kVA but not exceeding 10,000 kVA? Actually, according to HS2022, 8504.34 is "liquid dielectric transformers, having a power handling capacity exceeding 500 kVA," but attention must be paid to the subheading breakdown: 8504.21-8504.23 are liquid dielectric transformers listed by capacity, and 8504.31-8504.34 are other transformers listed by capacity. 8504.34 is specifically "other transformers, having a power handling capacity exceeding 500 kVA." Therefore, 850434 refers to transformers other than liquid dielectric transformers, with a capacity greater than 500 kVA. The goods are transformers with a capacity greater than 500 kVA, so they are classified under 8504. Since they are not liquid dielectric transformers (liquid dielectric transformers are classified under 8504.21-8504.23), nor are they small-capacity transformers (those with capacity ≤500 kVA are classified under 8504.31-8504.33), they are classified under 8504.34. If they were liquid dielectric with capacity >500 kVA, they should be classified under 8504.23.
Chapter
Chapter 85 covers electrical machinery and equipment and parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers, and parts and accessories of such articles. This chapter is the core chapter for electrical and electronic goods in the HS classification, involving a wide range of fields such as power generation, transformation, energy storage, electrical equipment, communications, and consumer electronics. Transformers, as key equipment for power transmission and conversion, are classified in this chapter.
Heading
Heading 8504 includes electrical transformers, static converters (such as rectifiers and inverters), and inductors. Transformers are used to change AC voltage and current, static converters are used to change current type or frequency, and inductors are used for energy storage and filtering in circuits. This heading is further subdivided by power capacity, use, etc. 850434 specifically refers to transformers with a capacity exceeding 500 kVA.
Digit Breakdown
The first 2 digits "85" represent Chapter 85 (electrical machinery and equipment and parts thereof). The 3rd-4th digits "04" represent heading 8504 (electrical transformers, static converters, and inductors). The 5th-6th digits "34" represent subheading 850434, namely liquid dielectric transformers with a capacity exceeding 500 kVA but not exceeding 10,000 kVA? Actually, according to HS2022, 8504.34 is "liquid dielectric transformers, having a power handling capacity exceeding 500 kVA," but attention must be paid to the subheading breakdown: 8504.21-8504.23 are liquid dielectric transformers listed by capacity, and 8504.31-8504.34 are other transformers listed by capacity. 8504.34 is specifically "other transformers, having a power handling capacity exceeding 500 kVA." Therefore, 850434 refers to transformers other than liquid dielectric transformers, with a capacity greater than 500 kVA.
Classification Basis
The goods are transformers with a capacity greater than 500 kVA, so they are classified under 8504. Since they are not liquid dielectric transformers (liquid dielectric transformers are classified under 8504.21-8504.23), nor are they small-capacity transformers (those with capacity ≤500 kVA are classified under 8504.31-8504.33), they are classified under 8504.34. If they were liquid dielectric with capacity >500 kVA, they should be classified under 8504.23.
📝 Declaration Elements
Product Name: The specific name of the declared goods, such as "power transformer," "dry-type transformer," etc., which must be consistent with the actual product. Use: Explain the application scenario of the transformer, such as "used for power transmission and distribution networks," "used for power supply to industrial equipment," etc. Brand: Fill in the transformer brand; if there is no brand, fill in "no brand." Model: Fill in the specific model, such as "S11-1000/10." Capacity: Rated capacity, in kVA, must be greater than 500 kVA. Dielectric Type: Distinguish between liquid dielectric (such as oil-immersed) and dry-type (such as epoxy resin cast). Cooling Method: Such as "natural cooling," "air cooling," "forced oil circulation," etc. Rated Frequency: Such as 50 Hz, 60 Hz, etc. Product Name: Dry-type power transformer; Use: Used for power supply system of urban rail transit; Brand: ABB; Model: SCB10-1000/10; Capacity: 1000 kVA; Dielectric Type: Dry-type; Cooling Method: Air cooling; Rated Frequency: 50 Hz. The capacity unit is mistakenly filled in as kW, resulting in incorrect classification. The dielectric type is falsely declared, reporting oil-immersed as dry-type. Ignoring the capacity threshold; those below 500 kVA should be classified under 8504.31-8504.33.
Product Name
The specific name of the declared goods, such as "power transformer," "dry-type transformer," etc., which must be consistent with the actual product.
⚠️ Writing only "transformer" is too general and does not distinguish the type.
Use
Explain the application scenario of the transformer, such as "used for power transmission and distribution networks," "used for power supply to industrial equipment," etc.
⚠️ The use description is vague, such as "used for transforming."
Brand
Fill in the transformer brand; if there is no brand, fill in "no brand."
⚠️ Confusing brand with model, or omitting it.
Model
Fill in the specific model, such as "S11-1000/10."
⚠️ The model is incomplete or incorrect.
Capacity
Rated capacity, in kVA, must be greater than 500 kVA.
⚠️ The unit is mistakenly filled in as kW or the capacity is omitted.
Dielectric Type
Distinguish between liquid dielectric (such as oil-immersed) and dry-type (such as epoxy resin cast).
⚠️ Reporting dry-type as oil-immersed, resulting in incorrect classification.
Cooling Method
Such as "natural cooling," "air cooling," "forced oil circulation," etc.
⚠️ Confusing cooling method with dielectric type.
Rated Frequency
Such as 50 Hz, 60 Hz, etc.
⚠️ Omitting the frequency, which affects classification.
Example： Product Name: Dry-type power transformer; Use: Used for power supply system of urban rail transit; Brand: ABB; Model: SCB10-1000/10; Capacity: 1000 kVA; Dielectric Type: Dry-type; Cooling Method: Air cooling; Rated Frequency: 50 Hz.
Common Mistakes：
The capacity unit is mistakenly filled in as kW, resulting in incorrect classification.
The dielectric type is falsely declared, reporting oil-immersed as dry-type.
Ignoring the capacity threshold; those below 500 kVA should be classified under 8504.31-8504.33.
🎯 Classification Logic
The core basis for classification is the type of transformer (liquid dielectric or other), rated capacity (whether it exceeds 500 kVA), and use. According to HS rules, liquid dielectric transformers are listed by capacity under 8504.21-8504.23, and other transformers are listed by capacity under 8504.31-8504.34. 8504.34 applies only to transformers that are not liquid dielectric and have a capacity greater than 500 kVA. If they are liquid dielectric and have a capacity >500 kVA, they should be classified under 8504.23. 850423 Liquid dielectric transformers, having a power handling capacity exceeding 10,000 kVA: This code is for liquid dielectric with capacity >10,000 kVA, while 850434 is for non-liquid dielectric with capacity >500 kVA. 850433 Other transformers, having a power handling capacity exceeding 1 kVA but not exceeding 500 kVA: The capacity range is different; 850433 is ≤500 kVA, while 850434 is >500 kVA. 850431 Other transformers, having a power handling capacity not exceeding 1 kVA: Very small capacity, used in electronic circuits, and completely different in use from the large-capacity power transformers of 850434. 850440 Static converters: Converters are used to change current type or frequency, while transformers only change voltage and current, not frequency. Confirm whether the transformer dielectric type is non-liquid. Verify whether the rated capacity is greater than 500 kVA. Check whether it is used for power transmission or distribution. Confirm whether it has conversion functions (such as rectification). Check the consistency of brand and model with the actual product.
Basis
The core basis for classification is the type of transformer (liquid dielectric or other), rated capacity (whether it exceeds 500 kVA), and use. According to HS rules, liquid dielectric transformers are listed by capacity under 8504.21-8504.23, and other transformers are listed by capacity under 8504.31-8504.34. 8504.34 applies only to transformers that are not liquid dielectric and have a capacity greater than 500 kVA. If they are liquid dielectric and have a capacity >500 kVA, they should be classified under 8504.23.
Confused Codes：
850423 - Liquid dielectric transformers, having a power handling capacity exceeding 10,000 kVA
This code is for liquid dielectric with capacity >10,000 kVA, while 850434 is for non-liquid dielectric with capacity >500 kVA.
850433 - Other transformers, having a power handling capacity exceeding 1 kVA but not exceeding 500 kVA
The capacity range is different; 850433 is ≤500 kVA, while 850434 is >500 kVA.
850431 - Other transformers, having a power handling capacity not exceeding 1 kVA
Very small capacity, used in electronic circuits, and completely different in use from the large-capacity power transformers of 850434.
850440 - Static converters
Converters are used to change current type or frequency, while transformers only change voltage and current, not frequency.
Self-Check：
✓ Confirm whether the transformer dielectric type is non-liquid.
✓ Verify whether the rated capacity is greater than 500 kVA.
✓ Check whether it is used for power transmission or distribution.
✓ Confirm whether it has conversion functions (such as rectification).
✓ Check the consistency of brand and model with the actual product.
❓ FAQ
How to distinguish 850434 from 850423? 850423 is for liquid dielectric transformers with a capacity exceeding 10,000 kVA, while 850434 is for non-liquid dielectric transformers with a capacity greater than 500 kVA. The key difference lies in the dielectric type and capacity range. If it is oil-immersed and has a capacity >10,000 kVA, classify under 850423; if it is dry-type and has a capacity >500 kVA, classify under 850434. If the transformer capacity is exactly 500 kVA, which code should it be classified under? Transformers with a capacity not exceeding 500 kVA are classified under 8504.31-8504.33. Specifically, capacity ≤1 kVA is classified under 850431, and 1 kVA < capacity ≤500 kVA is classified under 850433 (other transformers). Therefore, 500 kVA should be classified under 850433, not 850434. What is the difference in classification between dry-type transformers and oil-immersed transformers? Dry-type transformers belong to non-liquid dielectric transformers and are classified by capacity under 8504.31-8504.34; oil-immersed transformers belong to liquid dielectric transformers and are classified by capacity under 8504.21-8504.23. The subheadings are different, and the dielectric type must be accurately distinguished at declaration. What declaration elements are required when importing 850434 transformers? Product name, use, brand, model, capacity, dielectric type, cooling method, rated frequency, etc. are required. Among these, capacity and dielectric type are key and directly affect classification. It is recommended to attach product technical specifications for customs verification. If a transformer has a rectification function, which code should it be classified under? If the transformer also has a rectification function, it may belong to static converters (850440). However, if it is only a transformer and the rectification function is performed by separate equipment, it should still be classified under 8504.34. The judgment should be based on the main function of the equipment. What is the export tax rebate rate for 850434? The export tax rebate rate is adjusted according to national policies. It is recommended to check the latest rebate rate through the official website of the General Administration of Customs or the State Taxation Administration. Generally, the rebate rate for mechanical and electrical products is relatively high, but the actual query shall prevail. How to check the customs regulatory conditions for 850434? It can be checked through the "Import and Export Tariff" on the official website of the General Administration of Customs of China, or by using the "Customs Classification Pre-ruling" service. Regulatory conditions may include import licenses, CCC certification, etc., which need to be confirmed according to the specific use and destination. If a transformer has a capacity exceeding 500 kVA but is used for wind power generation, is there any special classification? Transformers for wind power generation are usually dry-type or oil-immersed, and the classification principles remain unchanged. If it is liquid dielectric and has a capacity >500 kVA, classify under 850423; if it is non-liquid dielectric and has a capacity >500 kVA, classify under 850434. Use does not affect subheading classification, but may affect regulatory conditions.
Q: How to distinguish 850434 from 850423?
A: 850423 is for liquid dielectric transformers with a capacity exceeding 10,000 kVA, while 850434 is for non-liquid dielectric transformers with a capacity greater than 500 kVA. The key difference lies in the dielectric type and capacity range. If it is oil-immersed and has a capacity >10,000 kVA, classify under 850423; if it is dry-type and has a capacity >500 kVA, classify under 850434.
Q: If the transformer capacity is exactly 500 kVA, which code should it be classified under?
A: Transformers with a capacity not exceeding 500 kVA are classified under 8504.31-8504.33. Specifically, capacity ≤1 kVA is classified under 850431, and 1 kVA < capacity ≤500 kVA is classified under 850433 (other transformers). Therefore, 500 kVA should be classified under 850433, not 850434.
Q: What is the difference in classification between dry-type transformers and oil-immersed transformers?
A: Dry-type transformers belong to non-liquid dielectric transformers and are classified by capacity under 8504.31-8504.34; oil-immersed transformers belong to liquid dielectric transformers and are classified by capacity under 8504.21-8504.23. The subheadings are different, and the dielectric type must be accurately distinguished at declaration.
Q: What declaration elements are required when importing 850434 transformers?
A: Product name, use, brand, model, capacity, dielectric type, cooling method, rated frequency, etc. are required. Among these, capacity and dielectric type are key and directly affect classification. It is recommended to attach product technical specifications for customs verification.
Q: If a transformer has a rectification function, which code should it be classified under?
A: If the transformer also has a rectification function, it may belong to static converters (850440). However, if it is only a transformer and the rectification function is performed by separate equipment, it should still be classified under 8504.34. The judgment should be based on the main function of the equipment.
Q: What is the export tax rebate rate for 850434?
A: The export tax rebate rate is adjusted according to national policies. It is recommended to check the latest rebate rate through the official website of the General Administration of Customs or the State Taxation Administration. Generally, the rebate rate for mechanical and electrical products is relatively high, but the actual query shall prevail.
Q: How to check the customs regulatory conditions for 850434?
A: It can be checked through the "Import and Export Tariff" on the official website of the General Administration of Customs of China, or by using the "Customs Classification Pre-ruling" service. Regulatory conditions may include import licenses, CCC certification, etc., which need to be confirmed according to the specific use and destination.
Q: If a transformer has a capacity exceeding 500 kVA but is used for wind power generation, is there any special classification?
A: Transformers for wind power generation are usually dry-type or oil-immersed, and the classification principles remain unchanged. If it is liquid dielectric and has a capacity >500 kVA, classify under 850423; if it is non-liquid dielectric and has a capacity >500 kVA, classify under 850434. Use does not affect subheading classification, but may affect regulatory conditions.
⚠️ Disclaimer: HS code classification, declaration elements, tariff rates and regulatory conditions on this page are for reference only and do not constitute legal advice on customs classification. Tariff rates and regulations are subject to change; the latest announcements from the General Administration of Customs and on-site determinations shall prevail. Please consult professional customs brokers or customs authorities before import/export.