Capacitor elements are enclosed in cylindrical aluminium cases and are filed with soft jelly i.e. semi solid vegetable oil, which is non toxic biodegradable and environment friendly. Capacitor elements are wound with metallised polypropylene film with extremely low loss factor.
The dielectric is self healing and the jelly impregnate protects zinc sprayed on the windings from the environment and provides better life & stable capacitors.
The capacitors have overprotection to disconnect it from supply in the event of internal failure