HQ 957324: Printed Circuit Board (PCB) Assemblies; AC Servo Drives; EN 85.04(II) HQ 954408

Native CBP ruling rendition. Applicability is fact-specific; modification/revocation relationships and original publisher date are retained. Publisher sentinel year0001 means unknown date, not a historical legal adoption.

                            HQ 957324

                         January 25, 1995

CLA-2 CO:R:C:M 957324  RFA

CATEGORY:  Classification

TARIFF NO.: 8504.40.80

Mr. David A. Johnson 
Reliance Electric Motion Control 
6950 Washington Avenue South
Eden Prairie, MN  55344

RE:  Printed Circuit Board (PCB) Assemblies; AC Servo Drives; EN 85.04(II)  HQ
     954408 

Dear Mr. Johnson:

     This is in response to your letter dated November 10, 1994, concerning the tariff
classification of the printed circuit boards assemblies for AC servo drives under the
Harmonized Tariff Schedule of the United States (HTSUS).  

FACTS:

     The merchandise, labeled as PAMJ printed circuit boards (PCBs), and identified
by your assembly part numbers 0042-6731(10 amp), 0042-6732 (20 amp), and 0042-6733 (30 amp), are to be installed into AC servo drives.  They will be manufactured in
Japan by your affiliate, Reliance Electric Japan (REJ).  The function of the PCBs is to
convert a single phase 50 or 60 Hz AC input voltage into a DC voltage (rectifier).  Then,
through pulse width modulation (PWM) techniques, the DC voltage is converted into a
variable frequency, variable 3-phase AC voltage for powering a brushless AC motor. 
The AC input is rectified with full wave power bridge rectifiers.  The rectified current
charges the bus capacitors to produce a filtered DC voltage.  The DC voltage, or DC
bus, has 2 primary purposes: first, the logic power supply transforms the high voltage
DC bus into lower voltage power for the signal level electronics; secondly, it provides
power to a brushless AC motor.  

     In order to provide the required power to the motor, both the frequency and the
current are controlled.  The PCB does not control either frequency or current, but it
provides the power switches that are controlled by external circuitry.  These power
devices are connected in a 3-way H-bridge to be able to switch each motor wire either
to the positive voltage bus or the negative voltage bus.  A control board, installed with
the PCB, precisely controls the power to a 3-phase AC motor and thereby controls its
motion.  The final product which contain these PCBs is used in industrial applications
which require precise control of motor position, velocity, or torque.  Applications include
specialty machines, packaging machines, and machine tools. 
  
ISSUE:

     Are the PCBs which are installed into AC servo drives, classifiable as electrical
static converters or as parts of electrical static converters under the HTSUS?

LAW AND ANALYSIS:

     Classification of merchandise under the HTSUS is in accordance with the
General Rules of Interpretation (GRI's).  GRI 1 provides that classification shall be
determined according to the terms of the headings and any relative section or chapter
notes.

     In HQ 954408, dated January 19, 1994, Customs dealt with the classification of
AC motor drives which were electrical devices designed to supply AC electricity
corresponding to a smooth sinusoidal wave-form at variable voltages and frequencies. 
The AC motor drive in that case was comprised of a DC supply obtained from a bridge
rectifier fed by 3-phase AC input lines, a filter capacitor circuit, an inverter consisting of
six power transistors, and a microprocessor.  The rectifier converted AC electricity into
DC electricity.  The DC supply was then filtered in the capacitor circuit and passed 
through the inverter to produce regulated AC electricity.

     In HQ 954408, Customs looked to the Harmonized Commodity Description and
Coding System Explanatory Notes (ENs) which constitute the Customs Cooperation
Council's official interpretation of the HTSUS.  While not legally binding, the ENs
provide a commentary on the scope of each heading of the HTSUS and are generally
indicative of the proper interpretation of these headings. See T.D. 89-80, 54 FR 35127,
35128 (August 23, 1989).   EN 85.04(II), page 1338, states as follows:

                   ELECTRICAL STATIC CONVERTERS

          The apparatus of this group are used to convert electrical energy in
     order to adapt it for further use.  They incorporate converting elements
     (e.g., valves) of different types.  They may also incorporate various
     auxiliary devices (e.g., transformers, induction coils, resistors, command
     regulators, etc.).  Their operation is based on the principle that the
     converting elements act alternately as conductors and non-conductors.

          The fact that these apparatus often incorporate auxiliary circuits to
     regulate the voltage of the emerging current does not affect their
     classification in this group, nor does the fact that they are sometimes
     referred to as voltage or current regulators.

          This group includes:

          (A)  Rectifiers by which alternating current (single or polyphase
               is converted to direct current, generally accompanied by a
               voltage change. 

          (B)  Inverters by which direct current is converted to alternating
               current.

     Based upon this description in EN 85.04(II), Customs determined that the AC
motor drive which included a rectifier and an inverter, was classifiable as a static
converter because the purpose of the merchandise was to convert electrical energy in
order to adapt it for further use. See HQ 954408.

     According to the information provided, the subject PCB assemblies convert a
single phase 50 or 60 Hz AC input voltage into a DC voltage (rectifier).  Then, through
pulse width modulation (PWM) techniques, the DC voltage is converted into a variable
frequency, variable 3-phase AC voltage for powering a brushless AC motor.  The AC
input is rectified with full wave power bridge rectifiers.  The rectified current charges the
bus capacitors to produce a filtered DC voltage.  Based upon this information, Customs
finds that the subject merchandise meets the definition of a static converter (inverter)
and is provided for under heading 8504, HTSUS.  It is classifiable under subheading
8504.40.80, HTSUS, as other static converters.

HOLDING:

     The PCB assemblies are classifiable under subheading 8504.40.80, HTSUS,
which provides for: "[e]lectrical transformers, static converters (for example, rectifiers)
and inductors; parts thereof: [s]tatic converters: [o]ther. . . ."   The general, column one
rate of duty is 2.7 percent ad valorem.  

                              Sincerely,



                              John Durant, Director
                              Commercial Rulings Division