AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR AN INNOVATION PATENT (Original) APPLICATION NO: LODGED: COMPLETE SPECIFICATION LODGED: ACCEPTED: PUBLISHED: RELATED ART: NAME OF APPLICANT: Lena Industrial Holding Limited ACTUAL INVENTOR(S): ADDRESS FOR SERVICE: LORD AND COMPANY, Patent and Trade Mark Attorneys, of 4 Douro Place, West Perth, Western Australia, 6005, AUSTRALIA. INVENTION TITLE: "Single module double pole multi-function RCBO" The following Statement is a full description of this invention including the best method of performing it known to me/us: TITLE "Single module double pole multi-function RCBO" 5 The present invention relates generally to a circuit breaker and specifically to a residual current circuit breaker with over current protection. Previous single module double pole multi-function RCBO's are unable to successfully mount 14k varistors due to space limitations and a lack of electromagnetic compatibility 10 along with other electric performance limitations. Previous single module double pole RCBO's have also faced difficulties in cutting arc contacts and cooling the electrical arcs as well as limited breaking capacity due to very small arc extinguishing systems The present invention attempts to overcome at least in part the aforementioned 15 disadvantages of previous single module double pole multi-function RCBO's. In accordance with one aspect of the present invention there is provided a single module double pole multi-function RCBO comprising a non-flammable cover, partition panel, handle, trip system, operating mechanism, instantaneous device, a circuit board, a bimetal 20 and an arc extinguishing system characterized in that a first cavity is placed adjacent the lower end of the arc extinguishing system along the bottom inner side of the cover and a second cavity on the lower side of the partition panel is connected to the first cavity. The present invention will now be described, by way of example, with reference to the 25 accompanying drawings, in which: Figure 1 is a top view of a Single module double pole multi-function RCBO in accordance with the present invention Figure 2 is a section view of a single module double pole multi-function RCBO as shown in Figure 1 along the line A-A. 30 Figure 3 is a section view of a single module double pole multi-function RCBO as shown in Figure 1 along the line B-B. 2 Figure 4 is an enlarged section view of the instantaneous device of the present invention as denoted by the area circled and numbered 4 in Figure 2 Referring to Figures 1 -3, single module double pole multi-function RCBO comprises 5 cover 1, a partition panel 2, a handle 3, an instantaneous device 4, a trip system 5, a test button 6, an operating mechanism 7, an arc extinguishing system 8, the cavity is placed in the lower arc extinguishing system, the circuit board 9 is placed in the cavity, the bimetal 11 is placed on the circuit board through the scarf 16 placed on the arc groove of the circuit breaker extends to the magnetic ring cavity on the input of the lower end circuit 10 breaker, this magnetic ring 15 is placed in the magnetic cavity. The N pole conductor on the magnetic ring along the L pole conductor into the input line side wall is connected with the N pole output and one side of the current coil 14, which leaves much more space on the circuit board to place varistors of up to 14k to greatly improve the electromagnetic compatibility capacity of the circuit breaker. 15 The operating mechanism 7 is mounted beside the circuit board cavity near to the upper striking plate 19; the instantaneous device is set on the upper of the operating mechanism 7. 20 Shown in Figure 4 is the above mentioned instantaneous device 4 comprising the handle 3 internally installed with accumulator spring 19 and instantaneous lock catch 20, instantaneous release 18, the instantaneous release 18 at one end is set in the pile 21 of the circuit breaker, about which it rotates, the opposing end engages push spring 22, the recess 23 in the center of the instantaneous release 18 is engaged by the instantaneous 25 lock catch 20 of the handle 3, the other end of the instantaneous lock catch 20 is attached to the bottom of the operating structure 7 (shown in figure 2). The instantaneous device is arranged such that the instantaneous force supplied is sufficient to break the arc that may occur when the circuit breaker is switched on or off 30 Referring to Figure 2, the operating mechanism 7 is mounted beside the circuit board cavity near to the top of the arc striking plate 19; the instantaneous device 4 is set on the 3 upper side of the operating mechanism 7. In use, the single module double pole multi-function RCBO is arranged as part of a household circuit panel or an industrial switch board, wherein it is arranged such that the 5 two poles are in contact with the earth and the neutral lines of a AC power circuit. Once arranged in a circuit the single module double pole multi-function RCBO acts as a combination of both a residual current device and a micro circuit breaker. The present invention acts in a similar manner to known RCBO's wherein response to residual 10 current being detected or if current draw reaches higher then the rated level the RCBO will switch to the off position. As is known in the art, switching high voltage, high current and high impedance circuits present a number of difficulties. It is common for an arc to form between the contacts of 15 any switch through which high current and high impedance flows. This arc allows the flow of electricity to continue even after the contacts of the switch has separated. This may create a dangerous situation wherein even though the switch is open the machine the circuit it is switching is still powered. 20 The present invention overcomes such difficulties by providing a larger cavity for the switch contacts to move, allowing the switch contact to move a greater distance apart hence making it more difficult for the arc to form and maintain itself. Secondly, the provision of a larger cavity allows for varistors of a greater capacity to be 25 included within the device. Varistors are commonly used in RCBO's to prevent large spike in voltage as devices are switched. As is known in the art large voltage spikes may occur when switching devices on or in the event of the device switching off and an arc forming. 30 The Varistors act as a cut off to high voltage surges as they act as a path of high resistance to low voltages and low resistance to high voltages. When switching occurs 4 and an arc form there is a corresponding spike in the voltage travelling through the circuit. When this voltage spike occurs the varistors act as a path of low resistance and as such act as a path of low resistance wherein excess current flows through the varistors. 5 Increasing the area inside the cavity to allow larger varistors therefore allows larger voltage spike to be prevented when switching is occurring in the circuit. Further, larger varistors also survive these large voltage spikes better then smaller varistors meaning an increased time before replacement of the varistors is necessary. 10 Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention. 5