FAQ

Frequently asked questions about copper wire coated with varnish.


1. How different with the color of varnish and the specification?
     Answer: The color of the liquid varnish is only a part to verify the kind and specification for coating copper wire. Varnish has many specifications depend on the usage of the product. Each feature has verified in different varnish focus on the temperature resistance.

2. What the meaning of 2-UEW and 1-PEW that indicate on manufacturer's label? And how the different?
     Answer: 2-UEW means that Polyurethane in coating on the wire.
                    1-PEW means that Polyester in coating on the wire.
                    Numbers on the front is indicated level of thickness of liquid varnish-coated wire, it is separated as the Class.
                    Class 0 means the thickest class of liquid varnish to the wire.
                    Class 1 means the thickness of liquid varnish is less than Class 0.
                    Class 2 means the thickness of liquid varnish is less than Class 1.
                    Class 3 means the least thickness of liquid varnish to the wire.
                   According to the requirements of JIS Standards and Industrial Standards (TIS).

3. How many types of liquid varnish coated copper wire? And how much of each type has degree of tolerance to temperature (oC)?
    Answer: There are many types of liquid varnish coated copper wire. Generally the most of them are as follows:
                     1.New thermelt enamelled copper wire (NEW).
                        - Resistant to temperatures up to 105 oC.
                     2. Polyvinyl formal enamelled copper wire (PVF).
                         - Resistant to temperatures up to 120 oC.
                     3. Polyurethane enamelled copper wire (UEW).
                         - Resistant to temperatures up to 130 oC.
                     4. Polyester enamelled copper wire (PEW).
                         - Resistant to temperatures up to 155 oC.
                     5. Polyester-Imide enamelled copper wire (EIW).
                         - Resistant to temperatures up to 180 oC.
                     6. Polyester-Amide-Imide enamelled copper wire (AIW).
                         - Resistant to temperatures up to 220 oC.

4.  What the meaning of SWG and AWG standard? And how different between SWG and AWG standard?
      Answer: SWG is the standard size of the wire in Metric Unit.
                     AWG is the standard size of the wire in British Unit.
                     The diameter of SWG wire number and AWG wire number is different. However, SWG wire number can be
                      referred to which AWG wire number in the same diameter.


5. How different between coatings varnish on the small diameter copper wire and the larger diameter wire?
     Answer: In general, the method of coating copper wire is the same. However, the diameter size of copper wire is used in
                  different machine and divided as following:


                  Copper wire diameter from 0.04 mm. - 0.75 mm. Coating varnish in horizontal machine
                  Copper wire diameter from 0.80 mm. - 2.60 mm. Coating varnish in vertical machine

                  For the large diameter copper wire, they cannot be coated in horizontal machine due to the large diameter and the
                  heavy weight. It will not steady and the varnish on the copper wire surface will be a wave and not smooth.


6. Can enameled copper wire refer to any standard?
    Answer: In general, enameled copper wire can refer to the following standards.

                   1. Thai Industrial Standard (TIS).
                       - TIS 174-2525 refer to the standard of polyurethane enameled round copper wires.
                       - TIS 226-2520 refer to the standard of polyester enameled round copper wires
                       Each standard uses different varnish for coating copper wire.               

                  2. Standards of Japanese industrial standards (JIS)
                      - JIS C3202: 1994  Enameled winding wires
                      - JIS C3003: 1984  Methods of test for enameled copper and enameled aluminium wires  

                  3. Standard of International electrotechnical commision (IEC)
                      - IEC 317 Series: The standard is referred to the type of varnish in coating copper wire.