Patent Description:
Electrical systems with packaged electrical and electronic components are known and are in use. For example, Motor Control Centers (MCC's) are used for power and data distribution in large and industrial operations. In MCC's, a variety of components, such as switchgear, semiconductor power electronic circuits, programmable logic controllers, motor controllers, and so forth, are housed in large electrical enclosures that may be subdivided into sections or columns, which may be further subdivided into compartments. The MCC includes associated bus bars, interconnections and supporting structures for distribution of electrical power to the various compartments.

Typically, the MCC is connected to a main power line that may feed three-phase AC power to horizontal bus bars of the MCC. The horizontal bus bars, in turn, may feed the three-phase power to vertical bus bars disposed in each of the sections or columns of the MCC. The vertical bus bars, in turn, may feed the three-phase power to various units (which typically include electrical components) that are installed in compartments of a section. The units, in turn, may provide power terminals (conductors), such as copper bus bars, for feeding the three-phase power to a system environment, such as motors, as may be required for various applications.

To connect an MCC to a system environment, a unit having a door or access panel, covering electrical components and sets of load stab conductors may typically be pushed into a compartment of the MCC. A first set of load stab conductors may connect to the three-phase power provided by the MCC, such as via the vertical bus bars. A second set of load stab conductors may connect to electrical connectors leading to screw terminals provided in adjacent wire-ways of the MCC, which may also have a door or access panel. The screw terminals, in turn, may lead to the system environment, such as a motor.

However, in some instances, such arrangements could risk electrical short-circuit and/or shock, such as when making electrical connections with doors or panels removed, leaving screw terminals exposed. It is therefore desirable to minimize the possibility of electrical short-circuit and/or shock where possible.

<CIT> discloses a terminal cover for a low-voltage miniature electrical appliance with a modular insulating casing equipped with a pair of caged terminals. The terminal cover is formed of a removable insulating cap composed of two elementary parts hinged with respect to one another. The first part can swing to cover the orifice that allows access to the tightening screw. The second part blocks off the passage to the caged terminal and is equipped with a locking rod which can be inserted between the contact region and the cage. The rod is provided with a hole for the passage of a screw, the tightening of which simultaneously causes the locking of the terminal cover and the connecting of the cable to the corresponding terminal.

<CIT> discloses a terminal block mounted on a profiled support. The profiles include a central core and two parallel wings perpendicular to the core with folded edges. The terminal block comprises a base whose front face supports two connection terminals and a protective cover fitting over the terminals. One of the connection terminals may receive the stripped end of a conductor while the other may receive the terminal ring on the end of a cable. The base plate on the rear face of the terminal is adapted to fit the profile on which the terminal block is to be mounted, with several sliding edges fitting on to the profile. A fixing device is fitted through the centre of the terminal block. The fixing device is placed perpendicularly with respect to the core of the profile to retain the terminal block in a chosen position mounted on the profile.

<CIT> discloses an electrical control unit that can be removed from its compartment for repair or changes of wiring. The document describes the compartment as providing on its rear side multiple busway envelopes of insulating material and an insulated block having clips. In each busway, apertures are provided to receive electrical connections. The control unit to be inserted in the compartment is comprised of a floor plate, a side plate, and a back plate. On the back of the control unit is a block which carries electrical probes for connecting with a bus of the busways via the apertures of the busway. Near the right edge of the back plate of the control unit an insulated terminal block is attached, which carries a plurality of conductive fingers. When the control unit is inserted into the compartment the probes enter the apertures of the busways, providing electrical input to the control unit, while the fingers of the terminal block engage with the clips of the insulating block, providing electrical output from the control unit.

It is the object of the present invention to provide an improved insulating cover for screw terminals.

The object is achieved by the subject matter of the independent claim.

The present inventors have recognized that a terminal assembly may be provided which utilizes an electrically insulating cover to electrically isolate upper portions of screw terminals. The electrically insulating cover could be made from plastic, rubber or some other electrical insulator, and could be mounted on a frame configured to engage with a frame supporting the screw terminals. While lower portions of the screw terminals may continue to electrically connect with electrical connectors for receiving load stab conductors (from a unit), upper portions of the screw terminals are electrically isolated to protect from short-circuit and/or shock, such as while a door or access panel of a wire-way is removed. The electrically insulating covers also include cable glands for circumferentially surrounding wires leading to the screw terminals. A retainer or retention clip may also be used to securely hold the electrically insulating covers to the frame supporting the screw terminals.

Aspects of the invention may provide improved protection for fingers or similarly sized objects which may encounter screw terminals, such as in accordance with IEC <NUM> IP20 (International Protection Rating for fingers or similar objects) standard. Aspects of the invention may also provide electrical isolation to protect from hazards such as "arc flash" (a phenomena in which a luminous discharge of current is formed when a current jumps a gap, through air or gas, in a circuit or between two conductors).

Aspects of the invention may provide a terminal assembly including a frame (extension load stab housing), rubber wire gland and covers, a wire spring clamp for protection, and a load stab. The load stab extension housing may be formed from a single molded part (which may also be electrically insulating). The cover and wire gland may be a combined (which may also be an electrically insulating material). The wire gland may be adapted to various wire (or cable) diameters by cutting off a section by section. A number may be provided on the wire gland itself to show a wire diameter after cutting. Metal spring clips may also be provided for improved safety in which removal of such clips may require a tool, such as pliers.

One or more advantages of the invention may include: an extension housing (frame) which may avoid complex and/or costly rework of current implementations and tooling; easier installation over previous designs, including by ensuring proper space/dimensioning for installation of equipment, such as lugs, wires and screws; easier implementation into older systems with older bracket and/or mounting types; IEC <NUM> IP20 (International Protection Rating for fingers or similar objects) compatibility; a simplified installation; an improved security of usage via difficult in disassembly without tools; a simplified mechanism for inspecting and verifying connections; compatibility with preexisting parts; combined wire gland (which may be rubber) and cover in a single part; and/or metal spring clips for improved retention and for allowing ease of installation or assembly, typically requiring tools for removal.

Specifically then, one aspect of the present invention provides an electrically insulating cover for a terminal assembly including: an upper surface configured to cover an upper portion of a screw terminal; and a cable gland attached to an end of the upper surface, the cable gland including a plurality of concentric rings of varying diameters, each ring being configured to circumferentially surround and substantially seal a cable or wire of a particular size. The electrically insulating cover is operable to electrically insulate an upper portion of a screw terminal.

Another aspect may provide a terminal assembly including: an electrical connector configured to receive a conductor upon the conductor being pushed into the electrical connector; a screw terminal having an upper portion configured to receive a conductor and a lower portion configured to electrically communicate with the electrical connector; and an electrically insulating cover disposed over the screw terminal. The electrically insulating cover is operable to electrically insulate the upper portion of the screw terminal.

Another aspect may provide an electrical system including: a compartment configured to receive a unit having an electrical component; a wire-way disposed adjacent to the compartment; multiple electrical connectors provided in the compartment, the electrical connectors configured to receive a set of load stab conductors upon a unit having a set of load stab conductors being pushed into the compartment causing the set of load stab conductors to be pushed into the electrical connectors; multiple screw terminals provided in the wire-way, each screw terminal having an upper portion configured to receive a crimped wire lug conductor and a lower portion configured to electrically communicate with an electrical connector; a frame supporting the multiple electrical connectors and the multiple screw terminals; and multiple electrically insulating covers disposed over the multiple screw terminals. The electrically insulating covers are operable to electrically insulate the upper portions of the screw terminals.

These and other features and advantages of the invention will become apparent to those skilled in the art from the following detailed description and the accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout, and in which:.

Referring now to <FIG> and <FIG>, an exemplar electrical system <NUM> is provided in which electrical units <NUM> of various types may be housed. The electrical system <NUM> may be, for example, a Motor Control Center ("MCC") or other industrial, commercial, marine, or other electrical system. In general, the electrical system <NUM> may provide one or more sections <NUM>, each forming a shell around a device mounting volume for supporting the units <NUM>. The shell may be made of any suitable material, such as heavy gage sheet metal, reinforced plastics, and so forth. The electrical system <NUM> may typically receive three-phase power from an external power supply, such as a power supply grid, and/or data signals, via appropriate conduits (not shown), and distribute the received power and/or data signals to one or more of the sections <NUM> in various manners. The sections <NUM> may be electrically isolated from one another, or alternatively, may be electrically joined with other sections <NUM>, such as via common horizontal power buses <NUM>.

The units <NUM> may each include a door for covering an assembly of components <NUM> that are supported within each unit <NUM> via known methods, such as screwed ("fixed feed" or "frame mounted") or snap-in ("withdrawable") engagement, thereby providing mechanical and electrical connection to the electrical system <NUM>. Exemplary components <NUM> of the units <NUM> may include relays, motor starters, and Programmable Logic Controllers ("PLC's"), among others. Doors for the units <NUM> may include, for example, a lever (such as a rotary lever to turn ON and OFF a Circuit Breaker inside the unit and enabling opening of the door when the Circuit Breaker is OFF), a lock for preventing the door from opening, and/or light for indicating a safe condition for opening the door. A latch rail (not shown) may be provided in each section <NUM> to interface with latches on the individual doors of the units <NUM>.

The sections <NUM> may also include wire-ways <NUM> in which line and load wiring, cabling and so forth may be installed to service the components <NUM>. The sections <NUM> may optionally include preconfigured isolation areas <NUM> for variations in which greater electrical isolation between sections <NUM> is desired, such as in compliance with IEC <NUM>-<NUM> Forms <NUM>, 3a, <NUM> or 4b.

Referring also to <FIG>, along a rear wall of each of the sections <NUM> may be disposed a vertical bus system <NUM> configured to facilitate distribution of power throughout a corresponding section <NUM>, such as in a plug-in manner. The bus system <NUM> may be generally formed as a backplane having slots <NUM> for receiving conventional stab-type electrical connections on rear surfaces of device supports received within a section <NUM>. Such slot and stab arrangements are generally known in the art. As illustrated, the slots <NUM> may be divided into pairs to receive a corresponding two-pronged stab for each phase of electrical power. Rows of such slots <NUM> may be provided to allow device supports to be mounted at various levels within a section <NUM>.

Referring now to <FIG>, an exemplary configuration of the bus system <NUM> of <FIG> is provided. The bus system <NUM> may include multiple power busses disposed within a section <NUM>. In the illustrated embodiment, the bus system <NUM> includes first, second and third vertical bus conductors <NUM> disposed proximal to one another, which may correspond to differing phases of a three-phase power system (power conductors). Further, the bus system <NUM> includes first, second and third horizontal bus conductors <NUM> disposed proximal to one another, which may also correspond to the differing phases of the three-phase power system (power conductors), but in a different direction.

In certain embodiments, the horizontal bus conductors <NUM> could be coupled to cabling that supplies three-phase power from an external power supply, such as a power supply grid, and the first, second and third horizontal bus conductors <NUM> could be coupled to the first, second and third vertical bus conductors <NUM>. Also, in certain embodiments, the horizontal bus conductors <NUM> of one section could be coupled (or "spliced") with the horizontal bus conductors <NUM> of another (flanking) section. In alternative embodiments, more horizontal and/or vertical bus conductors could be provided, such as for providing a neutral conductor, a protective earth, ground or additional power phase, or fewer horizontal and/or vertical bus conductors could be provided, as appropriate for the environment.

The bus system <NUM> may include a bus cover <NUM> and a rear bus support that will be described in greater detail below. In the illustrated embodiment, the bus cover <NUM> may include a molded sheet of synthetic material disposed over the vertical and horizontal bus conductors and may serve to prevent contact with underlying power busses except through the slots <NUM>. The vertical bus conductors <NUM> are typically made of a bar stock or tubing stock with a flat area that permits them to be mechanically and electrically coupled to corresponding horizontal bus conductors <NUM> in the bus system <NUM>.

Connection of component supports (such as mounted on plates or drawers, not shown) may be made by two pronged stabs that are received through the slots <NUM> and engage the individual bus bars behind the bus cover <NUM>. As described above, the bus system <NUM> further includes a bus support configured to support the vertical and horizontal bus conductors that is described in detail below with reference to <FIG>.

Referring now to <FIG>, an exemplary preconfigured isolated bus support <NUM> is illustrated for supporting the power busses of the bus system <NUM> of <FIG>. As illustrated, the bus support <NUM> may be a molding with vertical channels <NUM> to receive the vertical bus conductors <NUM> of <FIG>. Each of the vertical channels <NUM> may include rear protrusions <NUM> on a rear side <NUM> of the bus support <NUM>. In the illustrated embodiment, the bus support <NUM> mechanically supports the various horizontal and vertical bus conductors. Within the bus system <NUM>, and generally between the bus support <NUM> and the bus cover <NUM> (see <FIG>), each vertical bus conductor may generally include a connection portion that is engaged by stabs of component supports and a bus anchoring portion.

Accordingly, the horizontal bus conductors <NUM> (see <FIG>) may be generally supported on a rear surface of the bus support <NUM>, while the vertical bus conductors <NUM> (see <FIG>) may be supported on a front surface thereof. In the illustrated embodiment, the bus support <NUM> includes a series of apertures <NUM> or holes for receiving mounting bolts or screws. These apertures <NUM> will generally be aligned with corresponding apertures in rear of the electrical system <NUM> to support the bus system <NUM> when mounted therein. The vertical bus conductors <NUM> may be received within corresponding recesses of the vertical channels <NUM>. The recesses may generally be semicircular grooves in which the vertical bus conductors <NUM> may lie.

Opposing the rear protrusions <NUM>, which may be somewhat deeper than the recesses, are pockets designed to receive and accommodate stabs (not shown) of component supports that will protrude through the slots <NUM> in the bus cover <NUM>. Furthermore, the bus support <NUM> may include a series of apertures (not shown) that extend completely through the bus support <NUM> for mechanical and electrical connection to the horizontal bus conductors <NUM>.

In the illustrated embodiment, the bus support <NUM> may be formed as a single piece of molded plastic material. The material is preferably one that will not degrade or melt with elevated temperatures that may occur during normal operation. In certain embodiments, the bus support <NUM> may comprise glass filled polyester, a thermoset plastic. The bus support <NUM> could also include add-on bus support braces (not shown) disposed on the rear side of the bus support which may be configured to contact the channels to limit movement of the vertical bus conductors during a high current event.

Referring now to <FIG>, an isometric view of another exemplar electrical system <NUM>, which may be a section of a Motor Control Center (MCC), is provided in accordance with an embodiment of the invention. The electrical system <NUM> may include first doors <NUM> (or first panels) which may be opened to provide a compartment or volume of space for receiving a unit which may electrical components. The electrical system <NUM> may also include second doors <NUM> (or second panel) which may be opened to reveal a wire-way <NUM> disposed adjacent to the compartments covered by the first doors <NUM>.

For use in a system environment, one of the first doors <NUM> may be opened, and a unit having sets of load stab conductors may be pushed into the compartment. A first set of load stab conductors of the unit may be pushed into the compartment, for example, to engage the vertical bus conductors <NUM> for receiving three-phase power. A second set of load stab conductors of the unit may be pushed into the compartment, for example, to engage electrical connectors <NUM> configured to receive the second set of load stab conductors (see <FIG>). An electrical component of the unit may control electrical flow between the vertical bus conductors <NUM> (via the first set of load stab conductors) and the electrical connectors <NUM> (via the second set of load stab conductors). A lever <NUM>, which may be provided on the first door <NUM>, may actuate the electrical component to connect or disconnect the electrical flow, operating as a circuit breaker.

Referring also to <FIG>, an isometric view of the electrical system <NUM> in which second doors <NUM> has been removed, thereby exposing a wire-way <NUM> and screw terminals, is provided. The electrical connectors <NUM> (receiving the second set of load stab conductors from the unit) may, in turn, connect to lower portions of screw terminals <NUM>, such as via conductor rails <NUM>. Upper portions of the screw terminals <NUM>, such as screws <NUM>, may receive conductors, for example, in the form of crimped wire lugs <NUM> which may, in turn, be crimped to wires or cables leading to the system environment.

Referring now to <FIG>, an isometric view of electrical connectors <NUM> and screw terminals <NUM> of <FIG> is provided. The electrical connector <NUM> may be configured to receive conductors, such as a set of load stab conductors, upon the conductors being pushed into the electrical connectors <NUM>. The electrical connector <NUM> may be supported by an electrical connector frame <NUM>, which could be a single molded part, and which may be positioned in the compartment of the electrical system <NUM> behind the first door <NUM>.

The screw terminals <NUM> may have an upper portion, such as screws <NUM>, configured to receive conductors, such as crimped wire lug conductors crimped to wires or cables. The screw terminals <NUM> may also have a lower portion, such as the conductor rails <NUM>, for electrically communicating with a respective electrical connector <NUM>. The screw terminals <NUM> may be positioned in the wire-way <NUM> of the electrical system <NUM> behind the second door <NUM>. Crimped wire lugs conductors may be fastened, for example, by driving a screw <NUM> through the crimped wire lug to a conductor rail <NUM> and a screw terminal frame <NUM>, which could be a single molded part, supporting the screw terminals <NUM>. Wires or cables may also be crimped to the crimped wire lugs. Accordingly, a continuous electrical connection may be provided from the electrical connector <NUM> to the screw terminals <NUM>, and in turn, to the crimped wire lugs and crimped wires.

The electrical connector frame <NUM> may be attached to the screw terminal frame <NUM> in various ways, such as via a snap fit retention mechanism, a fastener and so forth. The electrical connector frame <NUM> and the screw terminal frame <NUM> may be regarded as a continuous frame supporting the electrical connectors <NUM> and the screw terminals <NUM>. In an alternative aspect, the electrical connector frame <NUM> and the screw terminal frame <NUM> could be molded as a single part.

Referring now to <FIG>, an isometric view of a frame element <NUM>, in communication with the electrical connector frame <NUM> and the screw terminal frame <NUM>, and electrically insulating covers <NUM> disposed over the screw terminals <NUM> of <FIG>, forming a terminal assembly <NUM>, is provided in accordance with an embodiment of the invention. The electrical insulating covers <NUM> electrically insulate the upper portion of the screw terminals <NUM>. The electrical insulating covers <NUM> could be made from plastic, rubber or some other electrical insulator, and could be mounted on the frame element <NUM> (see also <FIG>), which could be a single molded part, and which could be configured to engage with the electrical connector frame <NUM> and the screw terminal frame <NUM>. In some aspects, frame element <NUM>, the electrical connector frame <NUM> and the screw terminal frame <NUM> could be a continuous frame supporting the electrical connectors <NUM>, the screw terminals <NUM> and the electrically insulating covers <NUM>.

The terminal assembly <NUM> may include a single electrical connector <NUM> and screw terminals <NUM> configuration, or multiple electrical connectors <NUM> and screw terminals <NUM> (such as four electrical connectors <NUM> and four screw terminals <NUM> as illustrated). A single electrically insulating cover <NUM> could be provided to cover all of the screw terminals <NUM>, or alternatively, discrete electrically insulating covers <NUM> could be provided to cover each of the screw terminals <NUM> as illustrated.

The terminal assembly <NUM> may further include one or more retainer clips <NUM>, which could be metal spring clips, for example. Referring also to <FIG>, the retainer clip <NUM> may be mounted to a frame, such as the frame element <NUM>, via hooks <NUM>, to retain the electrically insulating covers <NUM> in a direction of the screw terminals <NUM>. The retainer clip <NUM> may also urge inwardly, toward the electrically insulating covers <NUM>, in a center area <NUM> to ensure exertion of a retention force. Removal of the retainer clip <NUM> may require a tool, such as pliers. Accordingly, the retainer clip <NUM> may further improve safety by further ensuring presence of the electrically insulating covers <NUM>.

Referring now to <FIG>, isometric top, bottom and front views, respectively, of the electrically insulating cover <NUM> are provided in accordance with an embodiment of the invention. The electrically insulating cover <NUM> may be configured to cover and electrically isolate an upper portion of a single screw terminal <NUM> as shown. In an alternative aspect, the electrically insulating cover may be configured to cover and electrically isolate upper portions of multiple screw terminals. The electrically insulating cover <NUM> may be manufactured as a single part molded from an electrically insulating material, such as rubber, plastic or the like.

The electrically insulating cover <NUM> may include a substantially flat, rectangular shaped upper surface <NUM> which may be disposed over the screw terminal <NUM>. An electrically insulating cover edge <NUM> may be provided below the upper surface <NUM> for contacting a frame element edge <NUM> (see also <FIG>) to ensure a continuous barrier providing electrical isolation between adjacent screw terminals. The upper surface <NUM> includes a channel <NUM> (or groove), near an outer edge, formed by opposing ridges for accommodating the retainer clip <NUM>. The upper surface <NUM> may also include text or other indicia conveying information to users, such as a warning of the presence of electrical voltage beneath the electrically insulating cover <NUM>.

As may best be seen in <FIG>, a positive retention feature <NUM> may be formed on an opposing, interior side of the upper surface <NUM>. The positive retention feature <NUM> may engage an aperture <NUM> or hole of the frame element <NUM> (see also <FIG> and <FIG>) for securing the electrically insulating cover <NUM> into position.

Referring also to <FIG>, the electrically insulating cover <NUM> also includes a cable gland <NUM> attached to an end of the upper surface <NUM>, such as in a front area. The cable gland <NUM> may consist of multiple concentric rings <NUM> of varying diameters for supporting a wire or cable in communication with the screw terminal. Each ring <NUM> is appropriately sized to circumferentially surround a conductor or cable of a particular diameter with substantial sealing contact, thereby providing continuous electrical isolation. The rings <NUM> may also be layered with differing distances from a screw terminal, such that a smaller ring <NUM> (which may be an inner ring) is further from the screw terminal, and a larger ring <NUM> (which may be outer ring) is closer to the screw terminal.

In operation, one or more excess rings <NUM> may be cut from the electrically insulating cover <NUM> in order to leave an appropriately sized ring <NUM> to circumferentially surround and substantially seal a wire or cable having a diameter corresponding to the appropriately sized ring <NUM>. Each of the rings <NUM> may be marked with an indicium <NUM>, such as a number, indicating corresponding ring diameters (or supported cable or wire sizes), or an American Wire Gauge (AWG) rating, or the like. The embodiment of <FIG> include, by way of example, seven possible ring diameter/size configurations being supported, including diameter ratings "<NUM>," "<NUM>," "<NUM>," "<NUM>," "<NUM>," "<NUM>" and "<NUM>," which may be expressed in millimeters. The indicium <NUM> reflects a diameter or size of the cable or wire being used after cutting.

As illustrated, in <FIG>, by way of example, a first electrically insulating cover <NUM> may have no rings <NUM> cut, leaving a ring size/diameter rating of <NUM>, allowing an electrically insulating sealing contact with a correspondingly sized <NUM> millimeter diameter wire <NUM>. A second electrically insulating cover <NUM> may have one ring <NUM> cut, leaving a ring size/diameter rating of <NUM>, allowing an electrically insulating sealing contact with a correspondingly sized <NUM> millimeter diameter wire <NUM>. A third electrically insulating cover <NUM> may have two rings <NUM> cut, leaving a ring size/diameter rating of <NUM>, allowing an electrically insulating sealing contact with a correspondingly sized <NUM> millimeter diameter wire <NUM>. Finally, a fourth electrically insulating cover <NUM> may have four rings <NUM> cut, leaving a ring size/diameter rating of <NUM>, allowing an electrically insulating sealing contact with a correspondingly sized <NUM> millimeter diameter wire <NUM>.

Referring now to <FIG>, isometric top and bottom views, respectively, of the frame element <NUM> are provided in accordance with an embodiment of the invention. The frame element <NUM> may be manufactured as a single part molded from an electrically insulating material, such as plastic or the like. The frame element <NUM> may include frame element edges <NUM> for contacting electrically insulating cover edges <NUM> to provide continuous electrical isolation between adjacent screw terminals. The frame element <NUM> may also include apertures <NUM> or holes for engaging positive retention features <NUM> of electrically insulating covers <NUM> for ensuring proper assembly. The frame element <NUM> may also include apertures <NUM> for receiving fasteners, such as screws or bolts, for mounting to the screw terminal frame <NUM> and, in turn, the electrical system <NUM>.

Referring now to <FIG>, an isometric view of the electrical system <NUM> of <FIG> is provided in which electrically insulating covers <NUM> are provided. The electrically insulating covers <NUM> electrically isolate the screw terminals <NUM> while the second door <NUM> is opened to reveal the wire-way <NUM>. Accordingly, short-circuit and/or shock protection may be provided, including with respect to IEC <NUM> IP20 and similar standards.

Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as "upper," "lower," "above," and "below" refer to directions in the drawings to which reference is made. Terms such as "front," "back," "rear," "bottom," "side," "left" and "right" describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms "first," "second" and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context.

When introducing elements or features of the present disclosure and the exemplary embodiments, the articles "a," "an," "the" and "said" are intended to mean that there are one or more of such elements or features. The terms "comprising," "including" and "having" are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance.

Claim 1:
An electrically insulating cover (<NUM>; <NUM>, <NUM>, <NUM>, <NUM>) for a terminal assembly, the electrically insulating cover (<NUM>; <NUM>, <NUM>, <NUM>, <NUM>) comprising:
an upper surface (<NUM>) configured to cover an upper portion (<NUM>) of a screw terminal (<NUM>), the upper surface (<NUM>) comprising a channel (<NUM>) formed on the upper surface (<NUM>) for accommodating a retainer clip (<NUM>) that extends along the whole length of an outer edge of the upper surface (<NUM>) and is mounted on a frame of the terminal assembly to retain the electrically insulating cover (<NUM>; <NUM>, <NUM>, <NUM>, <NUM>) in a direction of the screw terminal (<NUM>), wherein the channel (<NUM>) is formed by opposing ridges extending along the outer edge of the upper surface (<NUM>); and
a cable gland (<NUM>) attached to an end of the upper surface (<NUM>), the cable gland (<NUM>) including a plurality of concentric rings (<NUM>) of varying diameters, each ring being configured to circumferentially surround and substantially seal a cable or wire of a particular size,
wherein the electrically insulating cover (<NUM>; <NUM>, <NUM>, <NUM>, <NUM>) is operable to electrically insulate an upper portion (<NUM>) of the screw terminal (<NUM>).