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Information for ruling 600015529
This section is Advance Tariff Ruling
- Start date
- 11 Jun 2026
- Expiry date
- 10 Jun 2029
- Commodity code
- 8511900090 (opens in new tab)
- Description
- Voltage regulators are intended for use within an alternator. Some intended purposes of the voltage regulator within the alternator include preventing the battery from over/under charging as this can affect the battery life significantly. Other purposes of these voltage regulators include are to protect electronic components/systems from voltage spikes/surges. They also are for maintaining consistent output voltage as the alternator voltage increases and decreases due to engine RPM, and to compensate for load variations from high-power systems. The voltage regulator will react to make sure the alternator matches the demand. The function of a voltage regulator within an alternator includes monitoring the voltage from the alternator output and battery. Other functions include controlling the magnetic field of the rotor by adjusting the field current provided by the battery to the alternator rotor. If the voltage is monitored as low from the alternator output or battery, then the magnetic field of the rotor is strengthened by the voltage regulator increasing the current to the rotor field winding. The opposite happens if the monitored voltage is too high resulting in the voltage regulator reducing/stopping the current to the rotor field winding. This means that the function of the voltage regulator is continuously adjusting the alternator rotor field current to keep the vehicle’s system voltage within a target range. Voltage regulators do not function as static converter, and these voltage regulators are a control circuit which regulate the alternator output voltage (indirectly) by controlling the rotor field current, and so they focuses on control functionality. In the alternator, the voltage regulator does not usually disconnect the alternator completely when a set voltage is exceeded. Instead, it reduces or cuts the rotor (field) current, which immediately lowers the alternator’s output voltage. Voltage is monitored continuously and the voltage regulator senses system/battery voltage. When the voltage set-point is exceeded the voltage regulator will reduce the rotor field current from the battery. This weakens the magnetic field in the rotor. Low magnetic field means the alternator generates less voltage thus stabilizing the voltage back into the desired range. This happens many times per second to keep voltage stable. Some systems can fully disable rotor field current due to over-voltage protection or when a fault code is triggered.
- Keywords
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- FOR MOTOR VEHICLES
- FOR PROTECTION
- VOLTAGE REGULATORS
- Justification
- Classification has been determined in accordance with the following: For the purposes of determining the commodity codes within which goods most appropriately fall, reg 3 (1) of The Customs Tariff (Establishment) (EU Exit) Regulations 2020 sets out that the rules of interpretation contained in the following have effect – a. Part Two (Goods Classification Table Rules of Interpretation) of the Tariff of the United Kingdom (Reg 3(1)(a)); and b. Notes to a section or chapter of the Goods Classification Table (Reg 3(1)(b)). GIR 1 has been used to classify this product by the terms of heading 8511 - Electrical ignition or starting equipment of a kind used for spark-ignition or compression-ignition internal combustion engines (for example, ignition magnetos, magneto-dynamos, ignition coils, sparking plugs and glow plugs, starter motors); generators (for example, dynamos, alternators) and cut-outs of a kind used in conjunction with such engines GIR 6 has been used to classify the goods to subheading level 851190 - Parts 10 Digit Code 8511900090 - Other for use in certain types of aircraft Also classified in accordance with :- Note 2 b to Section XVI Harmonized System Explanatory Notes (HSEN's) to Heading 8511 (L) Harmonized System Explanatory Notes (HSEN's) to Heading 9032 This heading also excludes (II) (a)