Coral®Seal™ is a single coil / bar VPI system with an epoxy Anhydride class F insulation. The main characteristic is that the coils are fully cured using a very standard VPI system, using special fixtures to make sure they are dimensional perfect and have very little voids in the straight and overhang parts.

Ideally used for medium voltage motors, generators, Turbo and hydro generator coils and bars.

Advantages and special features:

• CoralSealis a well established and testes single coil / bar Epoxy Anhydride system that is highly trusted and used for many years by the main OEM’s.
• CoralSealis widely used for motor and generator rewinding as well as for new machines.
• CoralSealis done using Drying, Impregnation and Curing before insertion, with Coral’s proven VPI systems and  is easy to use in repairs either in the field or at our customer’s shop.
• CoralSealis fully cured in both straight and overhang areas, making sure that there is very little or no air voids, and as such an ideal insulation, with ideal Partial Discharge levels.

Construction of insulation Materials

Conductor covering (Class F) :

• Enamel with Dalgass
• Enamel with Fiberglass
• Enamel with Mica

Mica tape and subsequent materials:

• Stack consolidation tape
• Mica putty
• Glassoflex sheet
• Glass mica tape
• Corona shield tape
• Stress grading tape
• Finishing tape / Paint.

Note: The materials shall be differed for coils and bars.

Impregnation Resin

• Epoxy Anhydride

Standard and special testing alternatives

• Interturn test
• Surge comparison test
• Coil resistance measurement
• IR test IEEE 43:2000
• AC HV Test IS 4722:2001
• Tan delta and Tip up test – IEEE 286:2000
• Surface resistance measurement
• Visual corona test
• Impulse test

TYPE TEST:

• Partial Discharge measurement IEEE 1434 : 2014
• Voltage Endurance test IEEE 1043 : 1996 & IEEE 1553 : 2002
• Thermal Cycling test IEEE 1310 : 2012.