TECHNICAL FIELD
[0001] The present disclosure relates to the field of RMU. More
particularly the present disclosure relates to an interlock assembly for the RMU.
BACKGROUND
[0002] Background description includes information that may be useful in
understanding the present invention. It is not an admission that any of the
information provided herein is prior art or relevant to the presently claimed
invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Conventionally, a ring switch of an RMU can be accessed to
change operating mode of the RMU. The RMU include multiple interlocks for providing access to the RMU at different points of time when the operation mode of the ring switch is to be changed such as while performing maintenance in the cable chamber. These multiple interlocks are used for safety and protection of operator or engineer who are working in vicinity or in the switchgear. These interlocks are governed by mechanism operation or position of ring switch. Generally, the interlocks are mounted on Operating mechanism of switchgear and are integral part of the switchgear mechanism. The operating mechanism can include an assembly of torsion spring, indication assembly, input shaft and output shaft. This assembly is three position assembly i.e. Earth-OFF-ON. When you operate mechanism, energy is stored in torsion spring and it is released instantaneously, operating mechanism with required load. Assembly and operation of these interlocks is completely dependent on operation of mechanism. Mechanism has a complex design and with high load. When interlock is mounted on mechanism any undesirable load may hamper the operating parts of interlock & thus causing fetal injury to operator & people nearby.
[0004] There is, therefore, a need of an improved interlock assembly for
the RMU which can be separate from the mechanism of the switchgear.

OBJECTS OF THE PRESENT DISCLOSURE
[0005] Some of the objects of the present disclosure, which at least one
embodiment herein satisfies are as listed herein below.
[0006] It is an object of the present disclosure to provide an interlock
assembly for the RMU, which can be mounted on face of the RMU.
[0007] It is an object of the present disclosure to provide an interlock
assembly for the RMU, which is easy to access.
[0008] It is an object of the present disclosure to provide an interlock
assembly for the RMU, which is easy to operate.
[0009] It is an object of the present disclosure to provide an interlock
assembly for the RMU, which requires less maintenance.
[0010] It is an object of the present disclosure to provide a cost-effective
interlock assembly for the RMU.
SUMMARY
[0011] The present disclosure relates to the field of RMU. More
particularly the present disclosure relates to an interlock assembly for the RMU.
[0012] An aspect of the present disclosure pertains to an interlock
assembly for facilitating access to a cable chamber of a ring main unit (RMU). The interlock assembly includes a base plate configured to be mounted on a face of the RMU. The base plate includes an opening corresponding to a ring switch of the RMU for allowing access to the ring switch. The opening has one or more set of cut-outs at circumference of the opening. A first cover plate operatively configured with the base plate, and the first cover plate is configured to move between a first position and a second position through a first switch associated with the first cover plate. The first cover plate is configured to cover a first set of cut-outs, allowing access to the ring switch for ON and OFF operation, of the one or more sets of cut-outs when the first switch is at the first position, and the first cover plate is configured to cover a second set of cut-outs, allowing access to the ring switch for earthing operation, of the one or more sets of cut-outs when the first switch is at the second position. A first interlock, on the base plate,

configured to move between a third position and a fourth position, and the first interlock is operatively configured with the first switch such that a movement of the first interlock between the third position and the fourth position allows the movement of the first switch between the first position and the second position. A vertical member selectively engaged with a door of the cable chamber of the RMU, and the vertical member is configured to be moved between a fifth position and a sixth position through a second switch, configured at the base plate, associated with the vertical member. Moving the first interlock at the fourth position allows disengaging the vertical member from the cable chamber, facilitating opening of the door for providing access to the cable chamber, by moving the second switch to the sixth position.
[0013] In an aspect, the first interlock at the fourth position may allow
movement of the first switch at the second position, and the first interlock at the
third position allows movement of the first switch at the first position.
[0014] In an aspect, the interlock assembly may comprise a second cover
plate configure to be moved between a seventh position and an eight position, facilitating access to the ring switch, through a third switch associate with the second cover plate, and the second cover plate at the seventh position restrict access to the ring switch and the second cover plate at the eight position allows access to the ring switch.
[0015] In an aspect, when the second cover plate is at the seventh position
the vertical member may be allowed to move the sixth position, and when the second cover is at the eight position the vertical member may be restricted to move the sixth position.
[0016] In an aspect, the interlock assembly may comprise a second
interlock, configured at the base plate, configured to move between a ninth position and a tenth position, and moving the second interlock to the tenth position may restrict the movement of the vertical member back to the fifth position and the movement of the second cover plate back to the eight position for restricting any unintended operation of the ring switch.

[0017] In an aspect, the interlock assembly may comprise a third interlock
configure with an indicator plate and a circular plate of the ring main switch. The third interlock may be configured to move between an eleventh position and a twelfth position, when the ring switch is at OFF operation.
[0018] In an aspect, the indicator plate may be configured to indicate a
current operation mode of the ring switch.
[0019] In an aspect, the circular plate may be configured to move along
with the indicator plate, when the ring switch is switched to OFF operation,
facilitating movement of the third interlock from the eleventh position to the
twelfth position. When the third interlock is moved to the twelfth position the
movement of the circular plate to an initial position may be restricted for
restricting any unintended switching of the ring switch to ON operation.
[0020] Various objects, features, aspects and advantages of the inventive
subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF DRAWINGS
[0021] 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. The diagrams are for illustration only, which thus is not a limitation of the present disclosure.
[0022] In the figures, similar components and/or features may have the
same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

[0023] FIG. 1A illustrates an exemplary representation of a front view of
interlock assembly and FIG. IB illustrates a rear view of interlock assembly, in
accordance with an embodiment of the present disclosure.
[0024] FIG. 2A illustrates an exemplary representation of integrating the
interlocking assembly with the RMU, in accordance with an embodiment of the
present disclosure.
[0025] FIG. 2B illustrates an exemplary representation of a cross-section
of the RMU along with the interlock assembly, in accordance with an
embodiment of the present disclosure.
[0026] FIG. 3 A illustrates an exemplary representation of the RMU is in
OFF operation, in accordance with an embodiment of the present disclosure.
[0027] FIG. 3B illustrates an exemplary representation of the RMU is in
earthing operation, in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0028] The following is a detailed description of embodiments of the
disclosure depicted in the accompanying drawings. The embodiments are in such detail 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 scope of the present disclosure as defined by the appended claims.
[0029] In the following description, numerous specific details are set forth
in order to provide a thorough understanding of embodiments of the present
invention. It will be apparent to one skilled in the art that embodiments of the
present invention may be practiced without some of these specific details.
[0030] The present disclosure relates to the field of RMU. More
particularly the present disclosure relates to an interlock assembly for the RMU.
[0031] The present disclosure elaborates upon an interlock assembly for
facilitating access to a cable chamber of a ring main unit (RMU). The interlock assembly includes a base plate configured to be mounted on a face of the RMU.

The base plate includes an opening corresponding to a ring switch of the RMU. The opening has one or more set of cut-outs at circumference of the opening. A first cover plate operatively configured with the opening, and the first cover plate is configured to move between a first position and a second position through a first switch associated with the first cover plate. The first cover plate is configured to cover a first set of cut-outs, allowing access to the ring switch for performing ON and OFF operation, of the one or more sets of cut-outs when the first switch is at the first position, and the first cover plate is configured to cover a second set of cut-outs, allowing access to the ring switch for performing earthing operation of the ring switch, of the one or more sets of cut-outs when the first switch is at the second position. A first interlock, on the base plate, configured to move between a third position and a fourth position, and the first interlock is operatively configured with the first switch such that a movement of the first interlock between the third position and the fourth position allows the movement of the first switch between the first position and the second position. A vertical member operatively engaged with a door of the cable chamber of the RMU, and the vertical member is configured to be moved between a fifth position and a sixth position through a second switch, configured at the base plate, associated with the vertical member. Moving the first interlock at the fourth position allows disengaging the vertical member from the cable chamber, facilitating opening of the door of the cable chamber for providing access to the cable chamber, by moving the second switch to the sixth position.
[0032] In an aspect, the first interlock at the fourth position may allow
movement of the first switch at the second position, and the first interlock at the
third position allows movement of the first switch at the first position.
[0033] In an aspect, the interlock assembly may comprise a second cover
plate configure to be moved between a seventh position and an eight position, facilitating access to the ring switch, through a third switch associate with the second cover plate, and the second cover plate at the seventh position restrict access to the ring switch and the second cover plate at the eight position allows access to the ring switch.

[0034] In an aspect, when the second cover plate is at the seventh position
the vertical member may be allowed to move the sixth position, and when the
second cover is at the eight position the vertical member may be restricted to
move the sixth position.
[0035] In an aspect, the interlock assembly may comprise a second
interlock, configured at the base plate, configured to move between a ninth
position and a tenth position, and moving the second interlock to the tenth
position may restrict the movement of the vertical member back to the fifth
position and the movement of the second cover plate back to the eight position for
restricting any unintended operation of the ring switch.
[0036] In an aspect, the interlock assembly may comprise a third interlock
configure with an indicator plate and a circular plate of the ring main switch. The
third interlock may be configured to move between an eleventh position and a
twelfth position, when the ring switch is at OFF operation.
[0037] In an aspect, the indicator plate may be configured to indicate a
current operation mode of the ring switch.
[0038] In an aspect, the circular plate may be configured to move along
with the indicator plate, when the ring switch is switched to OFF operation,
facilitating movement of the third interlock from the eleventh position to the
twelfth position. When the third interlock is moved to the twelfth position the
movement of the circular plate to an initial position may be restricted for
restricting any unintended switching of the ring switch to ON operation.
[0039] FIG. 1A illustrates an exemplary representation of a front view of
interlock assembly and FIG. IB illustrates a rear view of interlock assembly, in
accordance with an embodiment of the present disclosure.
[0040] FIG. 2A illustrates an exemplary representation of integrating the
interlocking assembly with the RMU, in accordance with an embodiment of the
present disclosure.
[0041] FIG. 2B illustrates an exemplary representation of a cross-section
of the RMU along with the interlock assembly, in accordance with an
embodiment of the present disclosure.

[0042] As illustrated, an interlock assembly 100 for the RMU 124 can
include a base plate 102 configured to be mounted on a face of the RMU 124. The base plate 102 can include an opening 104 corresponding to a ring switch of the RMU 124 for providing an access to the ring switch. The opening 104 can include one or more set of cut-outs at a circumference of the opening 104. A first cover plate 130 can be operatively configured with the opening 104. The first cover plate 130 can be configured to move between a first position and a second position through a first switch 108. The first cover plate 130 can be configured to cover a first set of cut-outs 106-1 of the one or more sets of cut-outs for allowing access to the ring switch for performing ON and OFF operation, when the first switch 108 is at the first position. The first cover plate 130 can be configured to cover a second set of cut-outs 106-2 of the one or more sets of cut-outs for allowing access to the ring switch for performing earthing operation of the ring switch, when the first switch 108 is at the second position.
[0043] In an embodiment, a first interlock 110 (can also be referred as
permissive earthing interlock) can be configured on the base plate 102 to move between a third position and a fourth position. The first interlock 110 can be operatively configured with the first switch 108 such that a movement of the first interlock 110 between the third position and the fourth position can allow the movement of the first switch 108 between the first position and the second position. When the first interlock 110 is at the third position, the movement of the first switch or the first cover plate can be restricted from the first position to the second position. When the first interlock 110 is at the fourth position, the movement of the first switch 108 or the first cover plate 130 can be allowed from the first position to the second position.
[0044] In an embodiment, a vertical member 112 can be removably or
selectively engaged with a door of the cable chamber 116 of the RMU 124. The vertical member 112 can be configured to be moved between a fifth position and a sixth position through a second switch 114. The second switch 114 can be configured at the base plate and associated with the vertical member 112. Moving the first interlock 110 at the fourth position can allow disengaging the vertical

member 112 from the cable chamber 116. This can facilitate opening of the door
of the cable chamber 116 for providing access to the cable chamber 116, by
moving the second switch 114 to the sixth position. The movement of first
interlock 110 at the fourth position can allow movement of the first switch 108 at
the second position, and the movement of the first interlock 110 at the third
position can allow movement of the first switch 108 at the first position.
[0045] In an embodiment, the interlock assembly 100 can include a
second cover plate 126 that can be configure to be moved between a seventh position and an eight position. This can facilitate access to the ring switch, through a third switch 128 can be associate with the second cover plate. The movement of the second cover plate 126 at the seventh position can restrict access to the ring switch. The second cover plate 126 at the eight position can allows access to the ring switch. When the second cover plate 126 is at the seventh position the vertical member 112 can be allowed to move the sixth position. When the second cover plate 126 is at the eight position the vertical member 112 can be restricted to move the sixth position.
[0046] In an embodiment, the interlock assembly 100 can include a
second interlock 118 (can also be referred as proof of earthing interlock) that can be configured at the base plate 102 to move between a ninth position and a tenth position. Moving the second interlock 118 to the tenth position can restrict the movement of the vertical member back to the fifth position and the movement of the second cover plate back to the eight position as well, for restricting any unintended operation of the ring switch. The interlock assembly 100 can comprise a third interlock 120 that can be configured with an indicator plate 122 and a circular plate 132 of the ring main switch. The third interlock 120 (can also be referred as proof of isolation interlock) can be configured to move between an eleventh position and a twelfth position, when the ring switch is at OFF operation. The indicator plate 122 can be configured to indicate a current operation mode of the ring switch. The operating modes of the ring switch can include OFF, ON, and earthing.

[0047] In an embodiment, the circular plate 132 can be configured to
move along with the indicator plate 122, when the ring switch is switched to OFF operation. This can facilitate movement of the third interlock 120 from the eleventh position to the twelfth position. When the third interlock 120 is moved to the twelfth position the movement of the circular plate 132 to an initial position can be restricted for restricting any unintended switching of the ring switch to ON operation. The first interlock 110, the second interlock 118, the third interlock 120, the vertical member 112 can be operatively coupled with the help of but not limiting to any or combination of moving arms, and latches, guide rails, guide ways, and hinges for achieving the intended operation of the interlock assembly. Each of the first interlock 110, the second interlock 118, and the third interlock 120 can be switched using their respective operation keys.
[0048] FIG. 3 A illustrates an exemplary representation of the RMU is in
OFF operation, in accordance with an embodiment of the present disclosure.
[0049] As illustrated, the second cover plate 126 is at the eight-position
allowing access to the opening 104, and the first cover plate 130 is at first position
to cover the first set of cut-outs 106-1 for allowing access to ON and OFF
operation of the RMU switch, and the first interlock 110 is at the third position
restricting access to the earthing operation of the RMU switch.
[0050] FIG. 3B illustrates an exemplary representation of the RMU is in
earthing operation, in accordance with an embodiment of the present disclosure.
[0051] As illustrated, the second cover plate 126 is at the eight-position
allowing access to the opening 104. The first interlock 110 is at the fourth position and the first cover plate 130 is at second position to cover the second set of cut-outs 106-2 for allowing access to earthing operation of the RMU switch. After earthing the RMU switch, the second interlock is shifted to the tenth position and key of the second interlock is removed.
[0052] Moreover, in interpreting the specification, all terms should be
interpreted in the broadest possible manner consistent with the context. In particular, the terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating

that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C ....and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.
[0053] 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
[0054] The proposed invention provides an interlock assembly for the
RMU, which can be mounted on face of the RMU.
[0055] The proposed invention provides an interlock assembly for the
RMU, which is easy to access.
[0056] The proposed invention provides an interlock assembly for the
RMU, which is easy to operate.
[0057] The proposed invention provides an interlock assembly for the
RMU, which requires less maintenance.
[0058] The proposed invention provides a cost-effective interlock
assembly for the RMU.

We Claim:

1. An interlock assembly (100) for facilitating access to a cable chamber (116) of a ring main unit (RMU), the interlock assembly (100) comprising:
a base plate (102) configured to be mounted on a face of the RMU (124), comprising an opening (104) to allow access to a ring switch of the RMU (124), and the opening (104) comprises one or more set of cut-outs at a circumference of the opening (104);
a first cover plate (130) operatively configured with the base plate (102), the first cover plate (130) configured to move between a first position and a second position through a first switch (108) associated with the first cover plate (130), wherein the first cover plate (130) is configured to cover a first set of cut-outs (106-1), allowing access to the ring switch for ON and OFF operation, of the one or more sets of cut-outs when the first switch (108) is at the first position, and the first cover plate (130) is configured to cover a second set of cut-outs (106-2), allowing access to the ring switch for earthing operation, of the one or more sets of cut-outs when the first switch (108) is at the second position;
a first interlock (110) configured on the base plate (102) to move between a third position and a fourth position, the first interlock (110) operatively configured with the first switch (108) such that a movement of the first interlock (110) between the third position and the fourth position allows the movement of the first switch (108) between the first position and the second position; and
a vertical member (112) selectively engaged with a door of the cable chamber (116) of the RMU (124), wherein the vertical member (112) is configured to be moved between a fifth position and a sixth position through a second switch (114), configured at the base plate (102), associated with the vertical member (112), wherein movement of the first interlock (110) at the fourth position allows disengaging the vertical member (112) from the door, facilitating opening of the door to provide

access to the cable chamber (116), by moving the vertical member (112) to the sixth position.
2. The interlock assembly (100) as claimed in claim 1, wherein the first interlock (110) at the fourth position allows movement of the first cover plate (130) at the second position, and the first interlock (110) at the third position allows movement of the first cover plate (130) at the first position.
3. The interlock assembly (100) as claimed in claim 1, wherein the interlock assembly (100) comprises a second cover plate (126) configure to be moved between a seventh position and an eight position, facilitating access to the ring switch, through a third switch (128) associate with the second cover plate (126), and wherein the second cover plate (126) at the seventh position restrict access to the ring switch and the second cover plate (126) at the eight position allows access to the ring switch.
4. The interlock assembly (100) as claimed in claim 3, wherein when the
second cover plate (126) is at the seventh position, the vertical member
(112) is allowed to move to the sixth position, and when the second cover
plate (126) is at the eight position, the vertical member (112) is restricted
to move the sixth position.
5. The interlock assembly (100) as claimed in claim 4, wherein the interlock assembly (100) comprises a second interlock (118) configured at the base plate (102) to move between a ninth position and a tenth position, and wherein movement of the second interlock (118) to the tenth position restricts the movement of the vertical member (112) back to the fifth position and the movement of the second cover plate (126) back to the eight position for restricting any unintended operation of the ring switch.
6. The interlock assembly (100) as claimed in claim 1, wherein the interlock assembly (100) comprises a third interlock (120) configured with an indicator plate (122) and a circular plate (132) of the ring main switch, wherein the third interlock (120) is configured to move between an

eleventh position and a twelfth position, when the ring switch is at OFF operation.
7. The interlock assembly (100) as claimed in claim 6, wherein the indicator plate (122) is configured to indicate a current operation mode of the ring switch.
8. The interlock assembly (100) as claimed in claim 6, wherein the circular plate (132) is configured to move along with the indicator plate (122), when the ring switch is switched to OFF operation, facilitating movement of the third interlock (120) from the eleventh position to the twelfth position, and when the third interlock (120) is moved to the twelfth position the movement of the circular plate (132) to an initial position is restricted for restricting any unintended switching of the ring switch to ON operation.