VPI vs Resin Rich.pdf

Difference between VPI and resin rich system Disadvantages of Resin Rich coils : 1)The thickness of slot insulation required is more resulting in a bigger slot size and so increases the machine size. 2)The air gap between coil to slot reduces heat dissipation due to high thermal resistance of air resulting in increased - I2R losses reducing the machine efficiency. 3)The slide fit coils vibrate twice the line frequency due to electro-magnetic forces rubbing with the slot inner surface. In due course of time, the wall insulations get damaged leading to failure of machine. Disadvantages of rewinding a machine from VPI technology to Resin Rich technology :

1)The wall thickness in case of VPI technology is comparatively less that required for Resin Rich technology as detailed below : It is evident from the above table that by rewinding a VPI insulated machine with Resin Rich insulation system, the size of copper has to be reduced suitably to accommodate thicker wall insulation of the coils. Further in Resin Rich system, the coils are inserted in the slots by slide fit which further reduces the copper size to achieve the sliding gap. The total reduction in size of copper leads to approximately 20% reduction in rating of the machine. 2) The presence of air gap between slot to coils reduces heat dissipation from the coils increasing the I2R losses which in turn increases the temperature by 10 to 15 degrees more than initial operating temperature reducing machine efficiency and also leading to faster insulation deterioration and early failure of machine. 3)Increases the possibility of slot insulation damages by rubbing of coils in slot during operation. 4) Increase in overhang length to ease feeding of coils into the slots increases the length and resistance of coil which in turn increases the I2R loss and reduces the efficiency of the machine.

© Siemens Ltd. All rights reserved.

Work shop facilities Overhead Crane facilities up-to 75 tons. VIP Plant 5 Meter Dia 12 meter hight Elctrical oven 12 ftsX 12 Fts Mobile crans upto 5 tons Dynamic balancing machine Up-to 3000 rpm weight 30 tons Test-bed for no load trail 6.6 KV 6 MW motor Lamination varnishing plant HT coil manufacturing plant

© Siemens Ltd. All rights reserved.

70 ton balancing machine

© Siemens Ltd. All rights reserved.

Handling Facility

© Siemens Ltd. All rights reserved.

© Siemens Ltd. All rights reserved.