FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A current transformer terminal system with phase segregated terminal box
APPLICANTS :
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR (S):
Wadbude Sahebrao, of Crompton Greaves Ltd, Machine (M7) Division, D-5, Industrial Area, MPAKVN, Mandideep - 462046, Madhya Pradesh, India; an Indian National.
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

Field of the Invention:
This invention relates to the field of current transformers.
Particularly, this invention relates to current transformers and terminal boxes.
Still particularly, this invention relates to a current transformer terminal system with phase segregated terminal box.
Background of the Invention:
A transformer is a device that transfers electrical energy from one circuit to another through transformer coils. Current transformers are used in industries, in power stations, sub-stations and the like.
A transformer, according to the existing art, requires two terminal boxes. One is the main terminal box and one is the stator terminal box. A terminal box is an enclosure which includes, mounts, and protects one or more terminals or terminal boards. The main terminal box is a single phase supply. The star terminal box is a three phase supply.
As per client site requirement, the main side terminal box may be at an operative left side and the star side terminal box may be at the operative right side. For some other clients, it may be required that the sides be exchanged.

There are further requirements that the client site may require positioning shorted 3-phases on either one of the two sides or may require a current transformer on either one of the two sides. In such situations, the boxes are to be mechanically and electrically interchanged to serve the purpose.
This is a laborious and otherwise cumbersome procedure.
There is a need for an assembly which provides for said interchangeability without the need to 'replace' the terminal boxes from one side to another.
Further, there is also a need for current transformers to be associated in order to be located along the star side terminal box.
Prior Art:
JP5312832 discloses a terminal box of current transformer for measuring instrument. It illustrates a terminal box of a current transformer for measuring instrument is provided with a terminal box body which is formed like one-end opened square a terminal box lid which is engaged with the terminal box body and formed like one-end opened square so as to form a rectangular box, and these are fixed by means of screws.
In existing practice, Non Phase segregated Terminal Box are used for CT mounting because the terminal Box size required is too large.

Currently, current transformers are being used or being mounted with non phase segregated Terminal box. A motor manufacturer can not use this terminal box in case of hazardous area application motors in the absence of Fault level certificate for non PSTB & IP55 certification. Also CMRI certification procedures may have problems for testing of Type 'e' & type 'n' test.
Objects of the invention:
An object of the invention is to provide a phase segregated terminal box which provides single phase supply as well as three phase supply.
Another object of the invention is to provide a current transformer in a terminal box which can be located on either sides of a transformer assembly.
Yet another object of the invention is to provide a terminal box which accommodates maximum size of CT with phase segregated Terminal Box.
Still another object of the invention is to provide a terminal box which will be able to foot mount a current transformer with minimum dimensions and which will also maintain all the clearances as per IS/IEC.
Summary of the Invention:
According to this invention, there is provided a current transformer terminal system with phase segregated terminal box, said terminal box comprises an entry means adapted to receive three phase supply to achieve a three phase (star)

terminal box and further includes a shorting link adapted to short said received three phase supply to achieve a single phase (main) terminal box, thereby providing an inverting option of inverting said terminal box from a main phase to star phase or from star phase to a main phase.
Typically, said box includes an earthing link to provide earthing between said box and a three phase supply.
Typically, said box includes an earthing pad.
Typically, said box includes an insulation mechanism.
Preferably, said box includes a glass epoxy liner insulation.
Typically, said box includes supports to provide leverage for cantilever mounting.
Typically, said box includes an auxiliary terminal box for said transformer.
Brief Description of the Accompanying Drawings:
Figure 1 illustrates a transformer with a main side terminal box on an operative left hand side of the transformer.
Figure 2 illustrates the internal arrangement of a main side terminal box of Figure 1.

Figure 5 illustrates a current transformer box with three phase supplies according to the prior art.
The invention will now be described in relation to the accompanying drawings, in
which:
Figure 3 illustrates a side view of the current transformer terminal system with
phase segregated terminal box;
Figure 4 illustrates a terminal box as described above;
Figure 6 illustrates a terminal box, connected with a three phase supply; and
Figure 7 illustrate a schematic mounting of the terminal box on the transformer housing.
Detailed Description of the Accompanying Drawings:
Figure 1 illustrates a transformer (12) with a main side terminal box (14) on an operative left hand side of the transformer.
Figure 2 illustrates the internal arrangement of a main side terminal box (14) of Figure 1. Here, the three phases R, Y, and B are shorted as shown by the reference numeral 16.
This terminal box provides direct mounting (18) on the frame of the transformer (12).

Similarly, on the opposite side or on the same side, as per user / client requirement, a star side terminal box may be mounted. Here, the 3 phase wires; R, Y, and B are kept segregated to provide a three phase supply. A current transformer with three phases on the primary side and a shorted secondary is thus formed.
In this system of the prior art, the entire terminal boxes need to be replaced if the three phases are to be shorted on the right hand side of the transformer.
According to this invention, there is provided a current transformer terminal system with phase segregated terminal box.
Figure 3 illustrates a side view of the current transformer terminal system with phase segregated terminal box (100). Typically, it contains a main side terminal box (14) and a star side terminal box (15).
In accordance with an embodiment of this invention, there is provided a phase segregated terminal box (100) adapted to invert the functions of said terminal boxes, i.e. to invert main side terminal box to star side terminal box and / or to invert star side terminal box to main side terminal box.
There is provided a shorting link (20). The shorting link may be used to short the three phase wires (R, Y, B) (22) of the transformer, received from the side terminal boxes. If the shorting link (20) is used, a main side single supply terminal box is achieved. If the shorting link is not used, a star side three phase supply terminal box is achieved. This terminal box is a modular box, i.e. it maybe removed from an

operative left to an operative right side. Therefore, by manipulating the shorting wires on the shorting link it is possible to achieve main side terminal box on either side as well as to achieve star side terminal box on either side. Merely, the terminal box needs to be shifted. Alternatively, the same terminal box may be attached on both sides, and merely the shorting link needs to be manipulated with respect to the phase wires being terminated upon it.
Figure 4 illustrates a terminal box as described above.
Reference numeral 24 refers to Insulation (glass epoxy liner) of the terminal box.
Reference numeral 26 refers to the housing of the terminal box.
Figure 5 illustrates an existing current transformer box (15) (according to the prior art) with three phase supplies as represented by the reference numerals 32, 34, and 36.
Figure 6 illustrates a terminal box (100), according to the invention, connected with a three phase supply (32, 24, 36).
Three phase supplies (32, 34, 36) enter the terminal box (100). They may be shorted interiorly uses the inherent shorting link to achieve a main side terminal box. If the supplies are not shorted a star side terminal box is achieved.
The box is designed with suitable supports (40) to provide leverage for cantilever mounting. An earthing link (42) and earthing pad (44) is provided.

There may also be provided an auxiliary terminal box (50) for the current transformer.
Figure 7 illustrate a schematic mounting of the terminal box (100) on the transformer housing (12).
While this detailed description has disclosed certain specific embodiments of the present invention for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim,
1. A current transformer terminal system with phase segregated terminal box, said terminal box comprising an entry means adapted to receive three phase supply to achieve a three phase (star) terminal box and further includes a shorting link adapted to short said received three phase supply to achieve a single phase (main) terminal box, thereby providing an inverting option of inverting said terminal box from a main phase to star phase or from star phase to a main phase.
2. A system and box as claimed in claim 1 wherein, said box includes an earthing link to provide earthing between said box and a three phase supply.
3. A system and box as claimed in claim 1 wherein, said box includes an earthing pad.
4. A system and box as claimed in claim 1 wherein, said box includes an insulation mechanism.
5. A system and box as claimed in claim 1 wherein, said box includes a glass epoxy liner insulation.
6. A system and box as claimed in claim 1 wherein, said box includes supports to provide leverage for cantilever mounting.

7. A system and box as claimed in claim 1 wherein, said box includes an auxiliary terminal box for said transformer.