FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETE SPECIFICATION (See section 10 and rule 13)
1. TITLE OF THE INVENTION:
"Stored Energy Actuating System for Circuit Breakers"
2. APPLICANT:
(a) NAME: Larsen & Toubro Limited
(b) NATIONALITY: Indian Company registered under the
provisions of the Companies Act-1956.
(c) ADDRESS: LARSEN & TOUBRO LIMITED,
L&T House, Ballard Estate, P. 0. Box: 278, Mumbai 400 001, India
3. PREAMBLE TO THE DESCRIPTION:
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

Stored Energy Actuating System for Circuit Breakers
Field of the invention
The present invention relates to electric switches and more particularly, to a stored energy actuating system for electrical switches.
Background of the invention
It is generally known to couple to a moulded case circuit breaker (MCCB), one of the release units, for providing overload and short circuit protections such as a thermal-magnetic release and a microprocessor based release.
Those releases are mechanically coupled together and with the MCCB basic unit and are provided by actuating means for actuating the operation of the electrical device (for example opening or closing of a circuit or similar).
For motor protection purposes, a delay of few seconds to minutes is enabled before tripping the motor due to overload current conditions whereas short circuit calls for an instantaneous response mechanism. Subsequently the release response time is expected to be of the order of micro seconds.
The trip life of mechanism involves de-latching of the mechanism and opening the breaker as fast as possible during fault conditions relayed by the relay units. Each trip cycle results in reduction of the life of the circuit breaker.
For motor protection a methodology formerly suggested uses a back up contactor which opens the circuit instead of operating the MCCB, by means of a module which relays the signal to the contactor hence considering operation of contactor at normal conditions. This method calls for a separate auxiliary module for the MCCB and a contactor; this increases the factor of failure by the presence of an external control gear device hence the operation and fault withstand capability of the contactor is expected to

be same as that of the MCCB indispensably. However, the usage and dependency on the contactor for clearing a faulty condition increases number of modules of the system and hence the cost.
Accordingly, there exists a need to for an EOM coordinator which communicates with the release effectively to put off the breaker instead of tripping the breaker in case of overloads.
Objects of the invention
An object of the present invention is to utilize effectively, already existing modules with a little modification condensing utility versus life span plot area.
Another object of the present invention is to improve trip life of the MCCB.
Summary of the invention
Accordingly, the present invention provides a stored energy actuating system for circuit breakers. The system includes an auxiliary module mounted on an UV accessory mounting cavity, a stored energy operating mechanism (SEOM) capable of being opening contacts, and an energy operating mechanism (EOM) coordinator for disabling the SEOM by communicating actual status of the circuit breaker remotely. The SEOM and the microprocessor based release are connected to the auxiliary module through buses. Wherein, the EOM acts after receiving command from the auxiliary module which in turn co-ordinates with the microprocessor based release to virtually trip the circuit breaker and after virtual trip of the circuit breaker, the EOM is disabled for remotely switching ON the circuit breaker thereby ensuring a conscious fault clearing action which ensures and avoids any faulty closing action of the circuit breaker
Brief description of the drawings
Figure 1 shows a flowchart for a stored energy actuating system for circuit breakers, in accordance with the present invention;

Figure 2 shows a electrically operating device using a stored energy actuating system of figure 1.
Detailed description of the invention
The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.
The present invention provides a stored energy actuating system for circuit breakers. The system utilizes effectively the already existing modules with a little modification condensing utility versus life span plot area. Further, a trip life of the circuit breaker is improved. Use of this system also facilitates the usage of electrically operating device because of co-ordination with the release. Since the system is separately powered up, UV conditions are cleared inherently by the system and since UV condition may also be an intentional power down, selective OFF can be enabled hence providing better end user selectivity.
Referring now to figure 1 and 2, there is shown a stored energy actuating system (100) for circuit breakers. The system includes an auxiliary module (10), an stored energy operating mechanism (SEOM) (20), a microprocessor based release (30) and an energy operating mechanism (EOM) coordinator (40).
The auxiliary device (10) is mounted on the UV accessory mounting cavity of the circuit breaker. The auxiliary device (10) is connected through buses with the stored energy operating mechanism (SEOM) (20) and the micro processor based release (30).
The energy operating mechanism (EOM) coordinator (40) acts after receiving command from the auxiliary device (10) which in turn co-ordinates with the microprocessor based release (30) to virtually trip the circuit breaker.

After virtual trip of the circuit breaker, the SEOM (20) is disabled for remotely switching ON the circuit breaker thereby ensuring a conscious fault clearing action. The disabling of the SEOM (20) is done through the EOM coordinator (40). This interlock ensures and avoids any faulty closing action of the circuit breaker.
As shown in figure 1 and 2, terminals 1 and 5 of the stored energy operating mechanism (SEOM (20)) connect to the external supply, and closing terminals 2 and 3 through a switch/ contact operates a solenoid and mechanism to switch ON the circuit breaker. The closing terminal 4 and 3 through a switch/ contact operate a motor to charge a spring in the SEOM (20) and also switch the circuit breaker to OFF/ Reset position.
The EOM coordinator (40) represented in the figure communicates the true status of breaker remotely. The EOM coordinator (40) controls the circuit breaker operation by means of either power switches or relay contacts. Specifically, provisional display of circuit breaker status and the microprocessor based release (30) settings through the SEOM (20) and push button/provision for remote fault clearing is enabled in the SEOM (20) by disconnecting operation of the solenoid unless enabled through this fault clearing provision. If the contact fails to open through the SEOM (20) which is indicated to the microprocessor based release (30) through the auxiliary device (10), as a poka yoke provision, a microcontroller trips the circuit breaker through the FSD. The interlock to disable ON command to solenoid in the SEOM (20) could be extended by mechanically tripping the circuit breaker if the SEOM (20) is dismounted from the circuit breaker. This communication also enables to count the number of electrical/mechanical operations at a remote location, the microprocessor based release (30) status, trip records and all the other data that could be captured with the present setup which aid in preventive maintenance.
The system (100) provides for sensing overload condition from a microprocessor based release (30) instantaneously and relaying pre-emptively to the electrically operating device to open the circuit breaker before the microprocessor based release (30) issues trip, thereby the trip life of mechanism is improved by more than twice a factor

effectively. Poka yoke is ensured by the release to issue trip if the feedback to EOM fails to operate
Fault conditions such as OL, UV which can afford a milliseconds delay can actually isolate the system by opening the circuit breaker rather than by tripping it, by sensing through the release and relayed by a normally Closed MOSFET and EOM can be allowed to act to clear the fault by this concept of virtual trip (opening of the circuit breaker)
The feedback taken from auxiliary device (10) and a trip alarm circuit by the system can be used to provide preventive maintenance features to the circuit breaker as a product by counting the number of ON/OFF cycles and ON/Trip cycles.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.

We claim
1. A stored energy actuating system for circuit breakers, the system
comprising:
an auxiliary module mounted on an UV accessory mounting cavity;
an stored energy operating mechanism (SEOM) capable of being opening contacts, the SEOM connected to the auxiliary module through buses;
a microprocessor based release connected to the auxiliary module through buses; and
an energy operating mechanism (EOM) coordinator for disabling the SEOM by communicating actual status of the circuit breaker remotely;
wherein, the EOM coordinator acts after receiving command from the auxiliary module which in turn co-ordinates with the microprocessor based release to virtually trip the circuit breaker and after virtual trip of the circuit breaker, the SEOM is disabled for remotely switching ON the circuit breaker thereby ensuring a conscious fault clearing action which ensures and avoids any faulty closing action of the circuit breaker.
2. The system as claimed in claim 1, wherein the EOM coordinator controls the circuit breaker operation by any one of power switches and relay contacts.
3. The system as claimed in claim 1, wherein if the contact fails to open through the SEOM, the situation is indicated to the microprocessor based release through the auxiliary device, and, a microcontroller trips the circuit breaker through the FSD.