Claims:
1. A system for reducing arc flash for a power protection device, the system comprising:
a door limit (DL) switch /alternate maintenance setting (AMS) switch that is configured to turn on whenever panel door of the protection device opens; and
a digital input output (DIO) module that is configured to sense digital input of the DL switch and convey the input to an electronic trip unit (ETU)/flux shift device (FSD) through a controller area network (CAN) wherein the electronic trip unit is configured with two sets of protection settings groups.
2. The system as claimed in claim 1, wherein said AMS switch connects power supply of 24V DC or 240V AC to the DIO.
3. The system as claimed in claim 1, wherein said protection settings groups comprises of one set group that is assigned for normal protection settings (group 1 settings) and second set group that is assigned to maintenance mode settings (group 2 settings).
4. The system as claimed in claim 3, wherein said normal protection settings are assigned as per relay coordination and said maintenance protection settings are configured with lowest pickup & delay settings which ensures efficient clearing of arcing fault.
5. The system as claimed in claim 1, wherein whenever the panel door is opened, the ETU changes its active protection set group from normal protection settings to maintenance protection settings.
6. The system as claimed in claim 1, wherein in case of arcing fault during maintenance operation, the protection device clears the fault as per the set group 2 settings.
7. The system as claimed in claim 1, wherein normal protection settings automatically gets restored when the panel door is closed.
8. The system as claimed in claim 1, wherein the protection settings are configured to be remotely set to a lower pickup & delay settings during maintenance operations.
9. A method for reducing arc flash for a power protection device, the method comprises the steps of:
assigning set group 1 (normal protection settings) as default protection settings and displaying all metering parameters such as but not limited to current, voltage, power with the help of the DIO module;
checking if the DIO module is connected to release and checking if AMS switch is on; and
assigning set group 2 (maintenance protection settings) as protection settings and generating an audio/visual indication for the initialization of maintenance mode and generating an event log.
10. The method of claim 9, wherein the method further comprises steps of setting input voltage of AMS switch to 24V DC or 230V AC.
, Description:
TECHNICAL FIELD
[0001] The present disclosure relates generally to power protection devices for protecting electrical systems from fault current conditions. In particular, the present invention discloses a system and method of limiting arc flash and let through energy for a power protection device during maintenance operations.

BACKGROUND
[0002] Switchgear devices are commonly employed in electrical power distribution systems for enclosing circuit breakers and switching equipment associated with the distribution system. Typically, switchgear devices consists a number of stacked or compartments, each of the switchgear compartments receiving electrical power from a power source and distributing the electrical power through a feeder circuit to one or more loads. Generally, each of the switchgear compartments includes circuit breakers for interrupting electric power in a particular feeder circuit in response to hazardous current overloads in the circuit.
[0003] In addition to current overloads, the switchgear device may encounter other hazardous conditions known as arcing faults. Arcing faults occur when electric current arcs or flows through ionized gas between conductors, between two ends of broken or damaged conductors, or between a conductor and ground in the switchgear device. Particularly in medium and high voltage power distribution systems, the ionized gas associated with arcing faults may be released at pressures and temperatures sufficient to severely damage or destroy the switchgear equipment and/or cause severe burning injuries or death to operating personnel.
[0004] Thus there is a need of effective system and method of protecting switchgear devices and operating personnel from arc flash by limiting the arc flash or let though energy during the maintenance operation.

OBJECTS OF THE INVENTION
[0005] A general object of the present disclosure is to provide a system and method for limiting arc flash that improves safety of switchgear device and operating personnel.
[0006] Another object of the present disclosure is to provide a system and method for limiting arc flash that automatically switches protection settings from normal mode to maintenance mode.
[0007] Another object of the present disclosure is to provide a system and method for limiting arc flash that provides simple and reliable method to reduce fault clearing time.
[0008] Another object of the present disclosure is to provide a system and method for limiting arc flash that avoids nuisance tripping during planned maintenance operations.
[0009] Another object of the present disclosure is to provide a system and method for limiting arc flash that provides an audio/visual indication of the initialization of maintenance mode.
[0010] Another object of the present disclosure is to provide a system and method for limiting arc flash that saves life of service/maintenance engineers.

SUMMARY
[0011] The present disclosure relates generally to power protection devices for protecting electrical systems from fault current conditions. In particular, the present invention discloses a system and method of limiting arc flash and let through energy for a power protection device during maintenance operations.
[0012] In an aspect, the present invention discloses a system for reducing arc flash for a power protection device wherein the system consists of a door limit (DL) switch /alternate maintenance setting (AMS) switch that is configured to turn on whenever panel door of the protection device opens and a digital input output (DIO) module that is configured to sense digital input of the door limit switch and convey the input to an electronic trip unit (ETU)/flux shift device (FSD) through a controller area network (CAN) wherein the electronic trip unit is configured with two sets of protection settings groups.
[0013] In an aspect, the AMS switch connects power supply of 24V DC or 240V AC to the DIO.
[0014] In an aspect, the protection settings groups comprises of one set group that is assigned for normal protection settings (group 1 settings) and second set group that is assigned to maintenance mode settings (group 2 settings) wherein said normal protection settings are assigned as per relay coordination and said maintenance protection settings are configured with lowest pickup & delay settings which ensures efficient clearing of arcing fault.
[0015] In an aspect, whenever the panel door is opened, the ETU changes its active protection set group from normal protection settings to maintenance protection settings. Further, in case of arcing fault during maintenance operation, the protection device clears the fault as per the set group 2 settings.
[0016] In an aspect, the normal protection settings automatically get restored when the panel door is closed. Additionally, the protection settings are configured to be remotely set to a lower pickup & delay settings during maintenance operations.
[0017] In an aspect, the present invention also discloses a method for reducing arc flash and let through energy for a power protection device wherein the method includes the steps of
assigning set group 1 (normal protection settings) as default protection settings and displaying all metering parameters such as but not limited to current, voltage, power with the help of the DIO module,
checking if the DIO module is connected to release and checking if alternate maintenance setting (AMS) switch is on, and
assigning set group 2 (maintenance protection settings) as protection settings and generating an audio/visual indication for the initialization of maintenance mode.
[0018] In an aspect, the method further includes steps of setting input voltage of AMS switch to 24V DC or 230V AC.

BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0020] Fig. 1 illustrates an exemplary representation of various modules of system for reducing arc flash for a power protection device in accordance with embodiments of the present disclosure.
[0021] Fig. 2 illustrates an exemplary flow diagram of method for reducing arc flash for a power protection device in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION
[0022] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such details as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0023] Embodiments explained herein relate generally to power protection devices for protecting electrical systems from fault current conditions. In particular, the present invention discloses a system and method of limiting arc flash and let through energy for a power protection device during maintenance operations.
[0024] In an aspect, the present invention discloses a system for reducing arc flash for a power protection device wherein the system consists of a door limit (DL) switch /alternate maintenance setting (AMS) switch that is configured to turn on whenever panel door of the protection device opens and a digital input output (DIO) module that is configured to sense digital input of the door limit switch and convey the input to an electronic trip unit (ETU)/flux shift device (FSD) through a controller area network (CAN) wherein the electronic trip unit is configured with two sets of protection settings groups.
[0025] In an aspect, the AMS switch connects power supply of 24V DC or 240V AC to the DIO.
[0026] In an aspect, the protection settings groups comprises of one set group that is assigned for normal protection settings (group 1 settings) and second set group that is assigned to maintenance mode settings (group 2 settings) wherein said normal protection settings are assigned as per relay coordination and said maintenance protection settings are configured with lowest pickup & delay settings which ensures efficient clearing of arcing fault.
[0027] In an aspect, whenever the panel door is opened, the ETU changes its active protection set group from normal protection settings to maintenance protection settings. Further, in case of arcing fault during maintenance operation, the protection device clears the fault as per the set group 2 settings.
[0028] In an aspect, the normal protection settings automatically get restored when the panel door is closed. Additionally, the protection settings are configured to be remotely set to a lower pickup & delay settings during maintenance operations.
[0029] In an aspect, the present invention also discloses a method for reducing arc flash and let through energy for a power protection device wherein the method includes the steps of
assigning set group 1 (normal protection settings) as default protection settings and displaying all metering parameters such as but not limited to current, voltage, power with the help of the DIO module,
checking if the DIO module is connected to release and checking if alternate maintenance setting (AMS) switch is on, and
assigning set group 2 (maintenance protection settings) as protection settings and generating an audio/visual indication for the initialization of maintenance mode.
[0030] In an aspect, the method further includes steps of setting input voltage of AMS switch to 24V DC or 230V AC.
[0031] Fig. 1 illustrates an exemplary representation of various modules of system for reducing arc flash for a power protection device 100 wherein the system consist of a panel door limit (DL) switch/alternate maintenance setting (AMS) switch 102 wherein whenever the panel door opens, the AMS switch 102 turns on. Further, the AMS switch connects power supply of 24V DC or 240V AC to a digital input output (DIO) module 104. The DIO module 104 senses digital input of the AMS switch and convey the input to an electronic trip unit (ETU)/flux shift device (FSD) 108 through a controller area network (CAN).
[0032] In an aspect, the DIO module 104 passes the power input to a release 106 that checks the condition of AMS switch 102 and passes the power input to a breaker 112 via ETU/FSD 108 wherein the FSD 108 consists of a tripping device that can trip an electrical circuit during fault current conditions. An audio/visual indicator 110 is also provides that generated an alarms or a visual message whenever connection between the DIO module 104 and the release 106 is fulfilled.
[0033] In an aspect, the release also passes the power input to a power supply module 106 that checks the condition of the power supply and if safe conditions are met, it passes the power input to the breaker. However, if safe conditions are not met, the power supply module passes the power input to the FSD 108.
[0034] In an aspect, the breaker 112 is connected to a bus bar that processes the power input and passes it to various loads for electricity generation purposes.
[0035] In an aspect, the ETU 108 has two sets of protection settings groups wherein one set group is assigned for normal protection settings (group 1 settings) as per relay coordination and second set group is assigned to maintenance mode settings (group 2 settings) that are assigned as per lowest pickup & delay settings which ensures efficient clearing of arcing fault.
[0036] In an aspect, whenever the panel door is opened, the ETU 108 changes its active protection set group from 1 to 2. Further, during maintenance operations, if any arcing fault occurs, breaker 112 clears the fault as per the set group 2 settings (maintenance mode settings). Hence, the smallest fault can be detected and cleared efficiently that saves let through energy and arc flash hazards.
[0037] In an aspect, the normal set group 1 settings automatically get restored whenever the panel door is closed. Further, the system also provides a facility to remotely set breaker protection settings to lowest pickup & delay settings during maintenance. Thus, in an inadvertent event of arc flash over the let through energy is minimized. Hence, protecting the maintenance personnel from any severe or fatal injury.
[0038] In an aspect, the protection settings can be remotely brought back to the normal protection settings once the critical maintenance activity is completed.
[0039] In an aspect, various protection parameters are stored in the ETU 108 as a set group. Further, the ETU 108 is configured with two such set groups to hold setting parameters such as set group 1 and set group 2. At a time only one set group can be made as active set group and protection settings set in this group will be active.
[0040] Fig. 2 illustrates an exemplary flow diagram of method for reducing arc flash for a power protection device 200. At step 202, all the relevant modules and peripheral devices are initialized so that the system regulates the flow of current to various components of the protection device. Thereafter at step 204, normal protection settings (group1 settings) are assigned as the default protection settings. At step 206, all the input parameters are metered and displayed on the DIO module 104 wherein the metered parameters can be current, voltage, power, etc. Thereafter, at step 208, the connection of DIO module 104 with the release is checked and if the connection between DIO module 104 and release 106 is fulfilled, the process proceeds further to step 210. However, if the connection between DIO module 104 and release 106 is not fulfilled, step 206 is again processed.
[0041] In an aspect, at step 210, the input voltage of AMS switch 102 is set to 24V DC or 230 V AC. Thereafter, at step 212, the position of the AMS switch 102 is checked wherein if the AMS switch 102 is turned on, the process proceeds further to step 216 and if the AMS switch 102 is turned off the process proceeds further to step 220.
[0042] In an aspect, at step 216, the default protection settings are changed to group 2 settings wherein maintenance protection settings are assigned as the new protection settings and thereafter at step 218, an audio/visual indication is generated that resembles the initialization of maintenance mode and an event log is generated.
[0043] In an aspect, the audio/visual indicator 110 can be an alarm or an LED indicator and the DIO module 104 may consist of an OLED display device or an LCD display panel.
[0044] In an aspect, at step 220, the default protection settings are retained as group 1 settings wherein normal protection settings are retained as protection settings and thereafter at step 222, an audio/visual command reset is generated that resets the generation of an indication of an alarm or a visual message.
[0045] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION
[0046] The present disclosure provides a system and method for limiting arc flash that improves safety of switchgear device and operating personnel.
[0047] The present disclosure provides a system and method for limiting arc flash that automatically switches protection settings from normal mode to maintenance mode.
[0048] The present disclosure provides a system and method for limiting arc flash that provides simple and reliable method to reduce fault clearing time.
[0049] The present disclosure provides a system and method for limiting arc flash that avoids nuisance tripping during planned maintenance operations.
[0050] The present disclosure provides a system and method for limiting arc flash that provides an audio/visual indication of the initialization of maintenance mode.
[0051] The present disclosure provides a system and method for limiting arc flash that saves life of service/maintenance engineers.