Continuously Transposed Conductor

Main productions:
Paper covered PVF enamel CTC wire (epoxy, semi hard);
Paperless PVF enamel CTC wire (epoxy, semi hard);
Heat-resisting CTC wire with class 155 or above (epoxy, semi hard)

Main equipments: 7 CTC Machines.
Max strips for them: 15, 17, 47, 63, 79 and two lines is 31.

Annual capacity: 15000 tons CTC per year.

Product Introduction
Continuously Transposed Cable (CTC) is a type of winding wire, which continuously weaved by some strips of insulated rectangular wire according to two stacks arrangement, via special insulated materials. Mainly be used in manufacturing windings of various power transformers, tracking transformers and reactors.

Product Type
Polyvinyl acetal enameled with paper insulation CTC
Polyvinyl acetal enameled over coated bondable epoxy resin with paper insulation CTC
Polyvinyl acetal enameled with paper insulation, hardened copper CTC
Polyvinyl acetal enameled over coated bondable epoxy resin with paper insulation, hardened copper CTC
Polyester net covered CTC
Polyesterimide enameled with Nomex insulated paper CTC
Polyester fiber non-weaving modified polyester enameled CTC

Manufacturing Scope
Number of single conductor: 5-79(odd number)
Individual conductor dimension:
Conductor thickness, a: 0.95- 3.00mm
Conductor width, b: 3.00-13.00mm
Suggested width/thickness of single conductor: 2.5 < b/a < 7.5
Number of paper insulation layer: Max. 24 layers at one time
Max. Height of CTC bundles: 80mm
Max. Width of CTC bundles: 26mm

Materials
Single enameled wire: Class 120, 155 polyvinyl acetal enameled rectangular copper conductor; Class 120 polyvinyl acetal over coated bondable epoxy resin rectangular copper conductor; Polyvinyl acetal enameled, hardened rectangular copper conductor; Polyvinyl acetal over coated bondable epoxy resin, hardened rectangular copper conductor; Class 180 polyesterimide enameled rectangular copper conductor.
According to different electric insulation requirements to select Grade 1 enamel 0.08-0.11mm or Grade 2 enamel 0.12-0.16mm. Generally, epoxy resin increase of epoxy enameled rectangular wire is about 0.03-0.05mm.
The resistivity of soft copper is not more than 0.01724Ω Mm2/m at 20ºC. According to different mechanical strength, below proof stress RP0.2is recommended:
C1 RP0.2(>100~180)N/ mm2
C2 RP0.2(>180~220)N/ mm2
C3 RP0.2(>220~260)N/ mm2

Wrapping Insulation Materials
Kraft paper, Highdensity paper, High extensibility fibre paper, Thermally up-graded paper Nomex-410, Non-woven polyester cloth, Polyester fibre netting binding strand.

Structure Design And Dimension Calculation
Transposed pitch: The distance between two consecutive transposed units of CTC. Transposed pitch depends on minimum winding diameter and number of single conductor, simulation calculation of transposed pitch is:
S=D· π /n
S---Transposed pitch
D---Minimum winding diameter
N---Number of single conductor of CTC bundles

Under normal situation, transposed pitch is 10~14 times of individual conductor width, under special condition, could be 6~8times of individual conductor width.

Inter-column paper in order to enhance axial compressive strength of CTC and to avoid enamel scratch between strand stacks, could insert the inter-column paper or pressboard with special thickness. Suggested inter-column paper thickness is 0.13mm, generally, when (n-1)/2× A<10mm, then no need to insert inter-column paper, here A indicates thickness of single conductor.

Overall Dimension
The simple formula to calculate overall dimension of CTC is:
CTC bundles height H=1/2(n+1)A+
CTC bundles width W=2B+

Where in:
A---thickness of single enameled wire
B---width of single enameled wire
Dimension increase due to paper
Insulation (both sides)