HV COIL PRODUCTION

1. Wire Obtainment

a) We use Grade2 quality, enamel coated, rectangular shaped, electrolytic, fully-annealed, copper wire.

b) The thickness of the enamel coating is 0,12-0,17 mm and each layer can resist 200 degrees Celsius and 2000 Volts. The wire is drawn in machine and does not include burrs.

c) Isolation resistance of the enamel wire’s outer surface is increased by coating it by nomex pressband with a minimum thickness of 0,05 mm or with mica with a minimum thickness of 0,09 mm. We do not use glass coating in OG stator bobbins due to heating problem.

2. Herringbone Coils Preparation

The coils are passed through the reel and tensioning system and in the coil winding machine, they are wrapped according t the desired turn quantities using moulds prepared in appropriate dimensions.

3. Form Giving

After ensuring, by banding with flax band, that the isolations on the outer surfaces of the herringbone-prepared bobbins do not get damaged, they are given form in the forming  machine according to the original bobbin dimensions

4. Coil Molding and Roasting

a) The cavity section of the coil, which is wrapped by one layer of epoxy material, is heated for a period of 30 minutes and the smooth gathering of the bobbin wires is thus achieved.

b) Isolation material conforming to the Resinrich system, is wrapped according to the required number of layers by giving consideration to the cavity interval.

c) The coils, which are pressed with hydraulic pistons in moulds that are specially prepared according to the inter-cavity dimensions, are roasted in 130 degrees Celsius for a period of 1 hour, which provides that the resin inside them bleeds and completely wraps the material and that they are hardened by evacuating the air inside them from the flanks.

5. Isolation of the Coil Head

a) The heads of the coils, the cavities of which have been roasted, are isolated by being wrapped with isolation materials. The coil production is completed by attaching silicone macaron at the coil terminals.

b) Corona protection is provided by wrapping fully-conductive band on the coil sections that will stay inside the cavity and semiconductive band towards the coil head

6. Coil Tests

a) Hi- POT Test: Isolation test for the cavity section against the chassis.

b) Surge Test: Short-circuit test for the coils between the spirs.

c) Megger Test: Measuring the isolation values for the cavity section of the coil.

d) TanӨ ; Determination of isolation problems within the roasted epoxy.