CLA-2-85:OT:RR:NC:N1:109
Mike Wallin
Reivax North America Inc.
2001 University St., Suite 1700
Montreal, H3A 2A6
Canada
RE: The tariff classification of an Excitation System from Brazil
Dear Mr. Wallin:
In your letter dated July 25, 2013, you requested a tariff classification ruling.
The item concerned is referred to as the RTX Power – Static Excitation System. This system generally consists of three interconnected cabinets.
Cabinet one is the control cabinet; it contains a microprocessor and various other electrical elements. The microprocessor uses closed-loop PID logic, complete with limiters and other functions, to control the voltage of a synchronous machine.
Cabinet two contains an AC breaker/contactor and a DC circuit. The purpose of the AC breaker/contactor is to interrupt the current flowing to a thyristor bridge. There is typically a step-down transformer connected to the AC breaker/contactor to supply the excitation system’s power requirements. The DC circuit consists of an overvoltage protection circuit and a crowbar (2 anti-parallel thyristors), it’s purpose is to detect an overvoltage on the field winding of a synchronous machine and discharge the energy stored in the field winding. The DC circuit also has other components, such as a field ground relay for protecting the field of the synchronous machine and transducers for measuring field voltage/current.
Cabinet three contains the thyristor bridge. The purpose of the thyristor bridge is to convert AC voltage to DC voltage. Signals from the control cabinet decide the timing of the thyristors and hence the level of current the thyristor bridge puts out. The DC output is used to power/generate a magnetic field within the windings of a synchronous machine.
All three cabinets will be imported together. The cabinets will be physically and electronically interconnected. As individual cabinets, the components cannot accomplish their intended function, but together, the system supplies and controls the current from the thyristor bridge, which is connected to the field winding of the synchronous machine (customer supplied). The current gives rise to a magnetic flux in the air-gap between a rotor and a stator, which results in an induced voltage in the stator winding of the customer’s synchronous machine. The purpose of the excitation system is to maintain a steady voltage on the transmission line as customer loads are changing as well as providing reactive power support for inductive loads.
The three cabinets concerned form a functional unit. As such the classification determination will be made in accordance with Section XVI, Note 4, HTSUS. That note instructs us to classify a functional unit under the heading that provides for the overall function of the system. Based on the information supplied as well as research conducted by this office, it is the opinion of this office that the function of the system is to convert and supply electrical power to the windings of a synchronous machine, such as an electric generator. The function of converting electrical energy in order to adapt it for further use falls within tariff heading 8504.
The applicable subheading for the RTX Power – Static Excitation System will be 8504.40.9540, Harmonized Tariff Schedule of the United States (HTSUS), which provides for “Electric transformers, static converters and inductors…: Static converters: Other: Rectifiers and rectifying apparatus: Power supplies: Other.” The rate of duty will be 1.5%.
Duty rates are provided for your convenience and are subject to change. The text of the most recent HTSUS and the accompanying duty rates are provided on World Wide Web at http://www.usitc.gov/tata/hts/.
This ruling is being issued under the provisions of Part 177 of the Customs Regulations (19 C.F.R. 177).
A copy of the ruling or the control number indicated above should be provided with the entry documents filed at the time this merchandise is imported. If you have any questions regarding the ruling, contact National Import Specialist Steven Pollichino at (646) 733-3008.
Sincerely,
Deborah C. Marinucci
Acting Director
National Commodity Specialist Division