FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
PROVISIONAL SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A chamber for a capacitor- voltage transformer
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTORS
Shirke Kishor Shantaram and Bagi Alhad Annasaheb both of SI Division, Switchgear Complex, Crompton Greaves Ltd, A-3 MIDC, Ambad, Nasik - 422 010, Maharashtra, India, both Indian Nationals
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention:

Field of invention
The invention relates to a chamber for a capacitor-voltage transformer
Background of invention
Capacitor voltage transformers are used in power systems to step down extra high voltage signals and to provide low voltage signals for measurement or to operate a protective relay. In the capacitor unit, the stack of capacitors which are connected in series are impregnated with oil. During the operation of the transformer it is critical to maintain a positive pressure in the coupling capacitor unit to ensure a discharge free performance of the capacitor unit even at low temperatures. This would ensure that the high voltage capacitor elements are maintained in good condition.
Detailed description
Accordingly, the invention provides a hermetically sealed chamber for a capacitor-voltage transformer.
In one embodiment, the invention provides a chamber for a capacitor- voltage transformer, the chamber comprising a stainless steel casing provided with a bellow arrangement and coupled with an adapter plate having annular surface, the chamber being provided with a casting cover on the top, the casting cover being fastened and sealed to a


proprietary valve that open towards the chamber, to a plurality of plugs and to an adapter plate, the sealing being carried out by O ring seals, the casting cover being additionally fastened to the adapter plate by a clamping screw.
In a further embodiment the invention provides a capacitor-voltage transformer enclosed in a chamber comprising a stainless steel casing provided with a bellow arrangement and coupled with an adapter plate having annular surface, the chamber being provided with a casting cover on the top, the casting cover being fastened and sealed to a proprietary valve that open towards the chamber, to a plurality of plugs and to an adapter plate, the sealing being carried out by O ring seals, the casting cover being additionally fastened to the adapter plate by a clamping screw
The bellow arrangement in the chamber of the invention ensures safe and healthy working of the capacitor elements of the transformer. The chamber is hermetically sealed with pressurized gas inside. The various O ring seals provided to the chamber prevents the escape of oil and gas from the chamber and also avoids the mixing of the oil with the gas. Additionally, the annular surface of the adapter plate provides effective dissipation of heat generated due to resistive heating.
Dated this 31st day of March 2008