Description

The invention relates to switchgear assembly module interlock for a withdrawable part of a switchgear assembly and in particular a low voltage switchgear.

According to standard requirements based on the IEC 61439 series in order to prevent insertion of switches or breakers or fuse switches of removable,

demountable or pluggable or withdrawable modules in LV switchgears interlocks have to be provided. Most of these interlocks are complex to handle or do not offer high safety standard and constant precision and quality with a relatively high number of locking/ unlocking cycles

The object of the invention is to provide a more efficient and easier to handle solution for the interlocking of an electrical component or element of a removable,

demountable or pluggable module in a low voltage switchgear.

This object is achieved according to the invention by a switchgear assembly module interlock with the features of claim 1 .

Further embodiments and refinements of the invention as well as a corresponding switchgear assembly module are disclosed in further claims and the following description.

To prevent the removal/insertion of said module in the energized and de-energized positions a new simple way of interlocking and providing the necessary functionality a switchgear assembly module interlock according to the invention is presented. Said switchgear assembly module interlock for a switchgear assembly and in particular a low voltage switchgear assembly is characterized in that an interlock housing is provided and force-fit attached to a rotatable isolation shaft and wherein an interlock shaft is provided which is rotary connected and/or attached to said interlock housing and wherein in a first position of said isolation shaft and/or interlock shaft the interlock shaft is extended and in its locking position and wherein when the axle is turned by an angle of about 90° said locking shaft is retracted and in its unlock position and wherein the locking shaft contains at least two recesses and/or openings which are arranged in longitudinal direction at the interlock shaft and in each of the two positions at least one of the recesses and/or openings of the interlock shaft is in alignment with at least one corresponding recess and/or opening in the interlock housing.

In a further refinement breakers or fuse-switches are padlockable directly with door possibly being open.

According to the invention a module interlock is provided to prevent the

removal/insertion of said module in the energized and de-energized positions.

This interlock protects against insertion of the module with the main isolation device energized after removal for repair or maintenance, as the module will require energizing for testing once removed.

In a further embodiment the switchgear assembly module interlock fulfills the following standard I EC 61439-1 Edition 1 .0 2009-01 , Section 8.5.2 and the standard AS/NZ 3439.1 .2002 Section 7.6.4.2 and its requirements.

Furthermore, the interlock also has a function for padlocking in the off position within the module, independent of the padlock facility provided on the door interlock handle on the module door, which in particular is a requirement with the mining industry. Specific here is that mining industry requires padlocking with open door as well which is not possible with the normally used handles on the door. The invention, advantageous configurations and improvements of the invention and particular advantages of the invention will be explained and described in more detail with reference to exemplary embodiments of the invention illustrated in the attached drawings, in which:

fig. 1 show an exemplary module interlock in unlock position according to the invention, fig. 2 show an exemplary embodiment of an isolation shaft support device and interlock shaft guide, fig. 3 show an exemplary switchgear assembly module interlock in locking position with applied padlock scissor hasp, fig. 4show an exemplary switchgear assembly with switchgear assembly module interlock in unlock position with applied padlock scissor hasp, fig. 5 show an exemplary switchgear assembly with switchgear assembly module interlock in locking position, fig. 6 show an exemplary switchgear assembly with switchgear assembly module interlock comprising a shaft support device in locking position.

Fig. 1 shows an exemplary embodiment of a switchgear assembly module interlock for a switchgear assembly and in particular a MCCB (molded case circuit breaker) for low voltage switchgear assembly in the mining industry, providing an interlock housing which is force-fit attached to a rotatable isolation shaft and wherein an interlock shaft is provided which is rotary connected and/or attached to said interlock housing and wherein in a first position of said isolation shaft and/or interlock shaft the interlock shaft is extended and in its locking position and wherein when the axle is turned by an angle of about 90° said locking shaft is retracted and in its unlock position and wherein the locking shaft contains at least two recesses and/or openings which are arranged in longitudinal direction at the interlock shaft and in each of the two positions at least one of the recesses and/or openings is in alignment with at least one corresponding recess and/or opening in the interlock housing.

It is also an essential requirement for boards supplied to the mining industry within Australia to provide an interlock within the module as well as the normally interlock provided to padlock the isolating device on the fascia of the switchboard.

Said interlock is designed to protect against insertion of the module top rail (Item a) with the main isolation device (Item b) energized after removal for repair or maintenance, as the module will require energizing for testing once removed.

The interlock is made up of at least five parts to provide the above function (See Sketch A)

It provides as standard, the required features for the installation of either a single padlock or multiple padlocks with the addition of a standard padlock scissor hasp attachment (Item c).

This then allows the module isolation device (Item b) to be padlocked in either the on or off positions via movement of the interlock shaft (Item e) which is attached to the shaft provided (Item d) with the isolation device (Item b).

The single padlock set up and design stated above is based on certain requirements that allow the padlock to be installed, these requirements are:

• Padlock hasp max dia 6mm and/or

• Padlock hasp length min 50mm long.

The module interlock arrangement for an MCCB according to fig. 1 comprises switchgear assembly module interlock as described above as well as a module top rail (item A), wherein the module top rail comprises recesses and/or openings so that when the module isolation device (item B) is in position the interlock shaft of the module interlock may mesh or engage in at least one of said recesses or openings when put or moved into locking position. To ensure an easier positioning and movement of the interlock shaft an interlock shaft guide is provided (see fig. 2) to ensure and provide a directed and well controlled movement of the interlock shaft.

Furthermore, as presented in fig. 2 a MCCB shaft support device may be provided comprising a protection grommet, in particular made of an insulating material, with a bearing or pivot bearing for the isolation shaft.

In fig. 3 an exemplary switchgear assembly module interlock in locking position with applied padlock scissor hasp is disclosed, wherein an interlock housing is provided, which is force-fit attached to a rotatable isolation shaft and wherein an interlock shaft is provided which is rotary connected and/or attached to said interlock housing and wherein in a first position of said isolation shaft and/or interlock shaft the interlock shaft is extended and in its locking position and wherein when the axle is turned by an angle of about 90° said locking shaft is retracted and in its unlock position and wherein the locking shaft contains at least two recesses and/or openings which are arranged in longitudinal direction at the interlock shaft and in each of the two positions at least one of the recesses and/or openings is in alignment with at least one corresponding recess and/or opening in the interlock housing.

The interlock shaft has a polygonal cross-section and in particular rectangular or quadratic cross-section.

The interlock housing comprises a U-shaped plate with two side-walls arranged face to face. Both side walls comprise polygonal openings to interfere and/or interact with the isolation shaft.

Furthermore, the interlock housing comprises further openings for interaction of interlock shaft, padlock and interlock housing to lock the module interlock in locking or unlock position.

The interlock shaft is partly arranged between and rotary connected to the two side- walls of the interlock housing. Instead of a U-shaped plate with two side-walls as an alternative also a single plate may be provided.

In fig. 4 an exemplary switchgear assembly with switchgear assembly module interlock in unlock position with applied padlock scissor hasp is shown, wherein in fig. 5 said switchgear assembly module interlock in locking position is presented.

In fig. 5 the interlock shaft in locking position passes through one opening in the respective module top rail and accordingly the MCCB is fixed.

Furthermore as disclosed in fig. 6, the MCCB isolation unit switched "On" vertical bar prevent insertion if removed, and removal if module is in service. The interlock shaft will block and prevent insertion as it collides in this position with always existing compartment bottom plate directly on top of this module.