Last month a new Vacuum Pressure Impregnation (VPI) installation was set up and commissioned at EMRI Repair in Ede. With a diameter of 2.5 meters and a height of 4 meters, this is the largest VPI installation located in the Netherlands.
When a motor or generator has been fitted with new windings, it is very important that all insulating materials are impregnated with a special insulating varnish. Impregnating the windings using a VPI process creates the optimum conditions to preserve the windings and insulation materials.
Instead of immersing the rewound machines in the insulating varnish under atmospheric pressure, the VPI process will first create a vacuum inside the impregnation tank. During this vacuum phase, all residual moisture will vaporise. Subsequently, varnish is added to the windings and insulation under vacuum. After the vacuum phase, the impregnation tank is put under overpressure. During this overpressure phase, the varnish is pressed deep inside the windings. The VPI process prevents air being entrapped inside the windings.
Compared to a standard impregnation method of immersing, the VPI process ensures a much higher insulation quality and longer life of rewound machines.
Modern electrical installations, such as high-voltage generators, windturbine generators or frequency controlled motors, require higher insulation quality and improved durability. These demands are met using the VPI process.
With this investment, EMRI is taking a huge step forward in improving the quality and service for its customers.