Insulation Applications of MICA 3.3Kv, 6.6kv and 13.2Kv
Dry System and Resin Rich for coils into rotative Machines at themal class F (155ºC) and higher.
Materials for coils
– SWECOMica SR854T-2 F Class
– SWECOMica SR755T F Class
– SWECOMica SR854K H Class * Manofacture of insulated conductor: DGY-D-n & SGY-D-n (“Multi Yarn” for insulation)
Product use with conductor insulation
– SWECOMica SR751TG-2 (for continuous and discontinuous system) Apply SWECOMica SR751TY
– CDT conductive tape – CB 9020
– SCDT half conductive tape or grader
Head coils protection:
– glasscloth tape GT/6101 or Polyester cloth tape TWT/6301
Others products for medium and high voltage machines: (Contact us)
– Pre-Impregnated papers and fabrics.
– Fillers and Top Stick
– Impregnation resins.
We recommend the tape SWECOMica R755T. This film is defined as a Sandwich of one mica sweco paper layer between 2 external layers of polyester film. One side of polyester film has a thermoactivable adhesive.
SWECOMica SR755T version, carries adhesive to allow a good pre-consolidation.
Other versions like SWECOMica SR854T-2 (Class F) and SWECOMica SR854K (Class H) with PI. Defined for 3.3Kv – 6.6kv, the conductor can be insulated with two layers (butt-wrapped) to an overlap of 50%.
Consolidation with SWECOMica SR755T, will become over 130ºC.
SWECOMica SR853G is a tape composed by mica in B-staged/Glass. Mica is loaded with high resin component in state B, which offers penetration into the spokes, and also, a part of main insulation joined to followings Mica B-staged layers.
To prevent residues of epoxy resin into the mold, we propose a nonstick film. This film will also be employed, for the same function, to consolidate the main insulation
Consolidation – Main insulation – Heads:
Exinting two kinds of systems, defined as continious or discontinious, general product will be SWECOMICA SR853G, tape of Glass/Mica B-Staged. Applying as a continious System we can do it with tape or sheets. This is fully compatible and highly compact with the preconsolidation tape.
For a discontinious application system, at head or corners, SWECOMICA SR853G will facilitate taping and will let flexible head to allow placement in the slot. It’s fully compatible with SWECOMica SR751TG-2, and will become a compact block.
Head insulation will be cured after be assembled into the slot.
It can be automàtic or manually, we recommend do it always in the same direction and half overlaping. Taping tension is a quite critical point, to be sure there are none wrinkles or folds, taping should be done constantly and at 75N/25mm tension (1”). SWECOMica SR853G with 25mm is the tipycal application width.
To protect from partial discharges, CDT 3322C conductive tape, will be applied in just 1 layer with half overlaping. Thickness after pressing will be around 0’20 mm.
Preheat up press machine (100ºC)
Apply a few pression for 10 minuts. Then follow attached drawings.
Head (Overhang Insulation):
Usually, take as a reference 40%-50% of layers applied at straight part.
Voltages over 6Kv, gradient or semi conductive tape (SCDT) will be applied. Also, to avoid partial discharges, is comon to use special paint.
For head protection against injuries, is recommendable apply a woven tape (glass or polyester). Shall be 1 layer with half overlaping.