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 box with three phase cable shorting mechanism.
APPLICANTS :
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company.
INVENTOR (S):
Mishra Neetendra 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 mechanical and electrical equipment.
Particularly, this invention relates to the field of motors and motor assemblies.
Specifically, this invention relates to current transformer (CT) box(es) for motors assemblies.
More specifically, this invention relates to a current transformer (CT) box with three phase cable shorting mechanism.
BACKGROUND OF THE INVENTION:
A motor for electrical purposes, i.e. an electric motor, is a device which converts electrical energy to mechanical energy. For industrial use, the ratings of motor may typically be very high. They may be placed in housings or frames. It contains two main components; stator, rotor. The rotor is the non-stationary part of a rotary motor, which rotates because the wires and magnetic field of the motor are arranged so that a torque is developed about the rotor's axis. The stator is the stationary part of a rotor system. The rotor has a fanning action.
In High Tension Motors, a Current Transformer (CT) box is used. Current transformer (CT) is used for measurement of electric currents. A current transformer also isolates the measuring instruments from what may be very high voltage in the monitored circuit. This box houses current transformers associated with the motor. Typically, the motor is manufactured by a first entity for the customer which is a second entity. Typically, current transformers are manufactured by a third entity, for use by the second entity, on-site.

Current transformers are essential for testing of electrical motors. In the prior art designs of current transformer boxes, there was no provision for cable shorting arrangement, in the event of unavailability of current transformers. Hence, it was very difficult to test the motors without current transformers. At the same time, it was very unsafe to short the three phases of supply without having a proper mechanism. According to the prior art, manual holding of the three phase supply wires and manual shorting of the three phase supply wires was performed. This was a risky proposition from human point of view as well as from motor machine point of view.
There are typically three current transformers in the CT box, and on each current transformer, a single supply line of the three phase supply line is to be shorted. There is a need for an alternative shorting mechanism.
Also, if a current transformer breaks down, its replacement needs to be easy and safe (electrically).
OBJECTS OF THE INVENTION:
An object of the invention is to provide a current transformer box with shorting mechanism for motors for shorting three phase supply lines.
Another object of the invention is to provide a current transformer box with shorting mechanism for motors for shorting three phase supply lines in a safe and regulated manner.
Yet another object of the invention is to provide a current transformer box with shorting mechanism for motors for shorting three phase supply lines conforming to

pre-determined safety and electrical standards of electrical installation.
Still another object of the invention is to provide a current transformer box with shorting mechanism for motors for shorting three phase supply lines with the current transformer box housing current transformers.
SUMMARY OF THE INVENTION:
According to this invention, there is provided a current transformer box with three phase cable shorting mechanism, said mechanism comprises:
a. an elongate bar being an insulation bar located in a spaced apart manner from
the walls of said current transformer box; and
b. metal link with three holes located substantially at the centre of said link, said
holes being collinear holes adjacent each other and located longitudinally on
said link, said metal link being placed in a superimposed manner on said
elongate bar, said three holes adapted to receive R, Y and B phases for
shorting.
Typically, said mechanism comprises a pair of bosses adapted to be located on inner sides of lateral walls of said current transformer box.
Typically, said mechanism comprises a pair of brackets located at bosses which are located on inner sides of lateral walls of said current transformer box in order to space apart said bar and said link from the lateral walls of the box.
Preferably, said mechanism comprises a pair of L-shaped brackets located at bosses which are located on inner sides of lateral walls of said current transformer box in order to space apart said bar and said link from the lateral walls of the box.

Typically, said elongate bar is an Epoxy bar.
Typically, said elongate bar comprises three holes located substantially at the centre of said bar, said holes being collinear holes adjacent each other and located longitudinally on said bar.
Typically, said metal link is a Copper link.
Typically, said mechanism comprises fasteners for fastening said R, Y and B phases on said link.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a current transformer (CT) box of the prior art.
The invention will now be described in relation to the accompanying drawings, in which:
Figure 2 illustrates a current transformer (CT) box with three phase cable shorting mechanism; and
Figure 3 illustrates a current transformer (CT) box with three phase cable shorting mechanism and also illustrates the three phase supply wires shorted on the shorting mechanism.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a current transformer (CT) box of the prior art.

Current transformer Box (100) is used in High Tension (HT) Motors to give a mounting arrangement to current transformers. In this box, shorting of the three phases (R, Y and B) from the motor is performed using current transformers. Current transformers are procured from third party and have long lead time. Also, failure of current transformers is observed, at times. In the current transformer box of the prior art, there was no arrangement for shorting of three phases in case of unavailability of current transformers. Hence, it was not possible to run the motor without having current transformers. Also, if the manual shorting was done, it was found very unsafe.
According to this invention, there is provided a current transformer (CT) box with three phase cable shorting mechanism.
Figure 2 illustrates a current transformer (CT) box with three phase cable shorting mechanism.
Figure 3 illustrates a current transformer (CT) box with three phase cable shorting mechanism and also illustrates the three phase supply wires shorted on the shorting mechanism.
In accordance with an embodiment to this invention, there is provided a pair of bosses (12) adapted to be located on inner sides of lateral walls of the current transformer box (200). These bosses are shown as rectangular bosses in Figure 2 and 3 of the accompanying drawings.
In accordance with another embodiment of this invention, there is provided a pair of L-shaped brackets (14) located at the bosses (12). These bosses and L-shaped

brackets space apart the main portion of the shorting mechanism from the lateral walls of the box.
In accordance with yet another embodiment of this invention, there is provided an elongate bar (16) adapted to be the insulation bar located with the support of the reshaped brackets. The elongate bar is spaced apart from the walls of the current transformer box. The elongate bar is, typically, an Epoxy bar. The elongate bar may include three holes located substantially at the centre. The holes are collinear holes adjacent each other and located longitudinally on the bar.
In accordance with still another embodiment of this invention, there is provided a metal link (18) with three holes (21, 23, 25) located substantially at the centre. The holes are collinear holes adjacent each other and located longitudinally on the link. The metal link is placed in a superimposed manner on the elongate bar. The metal link is, preferably, a Copper link.
R, Y and B phases which are coming out of the motor are shorted on this copper link using fasteners. This is shown in Figure 3 of the accompanying drawings. Bolts (30) are provided for securing the R, Y, and B phase supply line wires.
Therefore, cable shorting mechanism has been provided by this invention in order to short three phases of power supply line which are coming out of motor. This cable shorting mechanism is provided by copper and epoxy links as explained above. Thus, the motor can be operated in accordance with appropriate safety protocol without even having current transformers.
The technical advancement of this invention lies in provisioning a shorting

mechanism comprising a metal link on an insulated bar, spaced apart from the walls of a current transformer box. The shorting mechanism is adapted to receive supply wires of three phases, for shorting, from a motor associated with the shorting mechanism. Therefore, the current transformer box with shorting mechanism eliminates the need for current transformer and provides reliable shorting for functioning of the associated motor.
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 box with three phase cable shorting mechanism, said mechanism comprising:
a. an elongate bar being an insulation bar located in a spaced apart
manner from the walls of said current transformer box; and
b. metal link with three holes located substantially at the centre of said
link, said holes being collinear holes adjacent each other and located
longitudinally on said link, said metal link being placed in a
superimposed manner on said elongate bar, said three holes adapted to
receive R, Y and B phases for shorting.
2. A current transformer box with three phase cable shorting mechanism as claimed in claim 1 wherein, said mechanism comprising a pair of bosses adapted to be located on inner sides of lateral walls of said current transformer box.
3. A current transformer box with three phase cable shorting mechanism as claimed in claim 1 wherein, said mechanism comprising a pair of brackets located at bosses which are located on inner sides of lateral walls of said current transformer box in order to space apart said bar and said link from the lateral walls of the box.
4. A current transformer box with three phase cable shorting mechanism as claimed in claim 1 wherein, said mechanism comprising a pair of L-shaped brackets located at bosses which are located on inner sides of lateral walls of

said current transformer box in order to space apart said bar and said link from the lateral walls of the box.
5. A current transformer box with three phase cable shorting mechanism as claimed in claim 1 wherein, said elongate bar is an Epoxy bar.
6. A current transformer box with three phase cable shorting mechanism as claimed in claim 1 wherein, said elongate bar comprising three holes located substantially at the centre of said bar, said holes being collinear holes adjacent each other and located longitudinally on said bar.
7. A current transformer box with three phase cable shorting mechanism as claimed in claim 1 wherein, said metal link is a Copper link.
8. A current transformer box with three phase cable shorting mechanism as claimed in claim 1 wherein, said mechanism comprising fasteners for fastening said R, Y and B phases on said link.