|Title of Invention||
A DEVICE FOR PREVENTING A SURGE ARRESTOR FROM BEING BYPASSED AFTER DISCONNECTION
|Abstract||A device for preventing a surge arrestor from being bypassed after disconnection comprising first and second modLlles, the first module being fixed to one end of a power supply cable and the second module incorporating a arrestor; means for detachably attaching the said modules to each other, said modules Whenever so attached, completing an electrical circuit Within them, such that With the first module connected to an electric power source,power from the said source is transmitted by the circuit through the surge arrestor to the said cable.|
This invention relates to a surge arrestor device.
Surge arrestors are used for protecting electrical and electronic equipment against voltage surges which can cause severe damage to such equipment.
Surge arrestors known to the art are usually of two kinds. The first kind is of.the non-disconnect kind, where the surge arrestor does not disconnect the equipment to be protected from the power supply on encountering surges, but, while arresting surges, continues to allow power supply to the load. In such cases, the surge arrestor is likely to fail after encountering repeated surges; however, even after such failure, the equipment continues to receive power supply thus ultimately leading to damage of the equipment. Evidently, such surge arrestors of the non-disconnect kind are not desirable.
The other kind of surge arrestor is of the disconnect, kind, where after encountering a surge from time, it arjrests the surge, and continues to work, as long as the surge is within a predetermined limit; however, if
^ surge happens to be above the limit, while arresting the surge, it destroys itself, thus disconnecting the the equipment from the power supply.
To make the equipment work again, the surge arrestor of this kind will have to be replaced by a fresh surge arrestor. The user cannot use the equipment until this is done.
While the disconnect kind of surge arrestor has its advantages as stated above, it has the drawback that the user may bypass the surge arrestor by removing it from the circuit and directly accessing the power supply.
It is therefore an object of this invention to propose a surge arrestor device which disconnects the equipment from the power supply after encountering a surge, but which, at the same time, also prevents the user from bypassing it after the disconnection. The equipment can be made to work again only, after the surge arresting unit is replaced.
Another object of this invention is to propose a surge
arrester device which is user-friendly in that after a disconnection takes place the surge arresting unit can be easily replaced by even an unskilled person.
Yet another object of this invention is to propose a surge arrester device which integrates the power plug unit, the surge arrestor unit, and the power supply cable into one compact system.
Various other advantages of this invention will be apparent from the further description thereof to follow.
The surge arrestor device, according to this invention, comprises first and second modules, the first module being fixed to one end of a power supply cable and the second module incorporating a surge arrestor; means for detachably attaching the said modules to each other, said modules whenever so attached, completing an electrical circuit within them, such that with the first module connected to an electric power source, power from the said source is transmitted by the circuit through the surge arrestor to the said cable.
This invention will now be described with reference to the accompanying drawings which illustrate, by way of example, and not by way of limitation, a preferred embodiment of the surge arrestor device proposed herein
Fig.l illustrating the first module from its rear
Fig.2 illustrating the first module from its front
Fig.3 illustrating the second module from its front
Fig.4 illustrating the second module from its rear
Fig.5 illustrating the two modules about to attach
Fig.6 illustrating the two modules attached to each
other (side view)
Fig.7 illustrating the two modules attached to each
other (front view)
Fig.8 illustrating the two modules attached to each
Fig.9 illustrating the circuitry of the embodiment
illustrated in Figs.l to 8, that is, with the first
module connectable to the electric power source
The surge arrestor device comprises first and second
modules Ml and M2.
The module Ml is fixed to one end of a power supply cable C while the module M2 incorporates a surge arrestor G. The other end of the cable C is for connection to the load, that is, the electric equipment to be protected.
Means are provided for detachably attaching the modules together. One of possible forms of such means comprise the connectors provided for the said modules which engage with each other, whenever the modules are attached to each other.
Additionally, the modules are provided with two holes H1 and H2 which are aligned against each other whenever the modules are attached as aforesaid. The holes are internally threaded to enable a screw to pass through them, in threaded engagement, when in alignment, to fasten the modules together securely, by the screw joint.
Detaching the modules is done by unfastening the screw and gently pulling the modules apart.
The modules Ml and M2, whenever attached to each other, . complete an electrical circuit (Fig.9) within the modules. Whenever the module Ml is connected to a power supply source Y by means of the connectors Ql, the electrical circuit is completed by the connectors Ql to Q2 to Q3 to surge arrester G to Q4 to Q5 to cable C and thence to the equipment to be protected. The earth wire E of the cable C is directly connected to the earth terminal E of the power supply through one of the connectors Ql. This is the circuit illustrated in Fig.9 for the embodiment illustrated in Figs. 1 to 8.
It will now be observed that on encountering a surge, the surge arrester G will arrest the surge, and continue to work as long as a surge does not exceed a predetermined limit. If a surge exceeds the predetermined limit, the surge arrestor will, while arresting the surge, gets destroyed. In this event, electric power to the cable C is cut off, thereby cutting off power supply to the equipment. In such a situation, it is impossible for the user to bypass the surge arrestor because the surge arrestor is
incorporated In the module M2 which is part of the power supply system of the surge arrestor device. The said equipment can be made to work again by replacing the module M2 with a fresh module M2. This is done by detaching the module M2 from the module Ml and attaching a fresh module M2 in the place of the former module M2. The replacement is quick and simple.
The pins and sockets illustrated are generally termed "connectors" in this specification, because these are not necessarily confined to the pin and socket type connectors,strictly so called, but can assume various forms as long as the purpose of electrical connection is served.
In Fig. 9 the phase and neutral wires are indicated by P and N. The earth wire is indicated by E.
The module M2 is provided with indicators J (visual/aural). For example, among the two indicators illustrated, when both indicators are on, the arrestor is in working condition. When one of the indicators is on and the other off, a wiring fault is shown to exist. When both indicators are off, the arrestor is shown to
have failed. The indicators will be given any desired colour to distinguish between the two.
The module Ml is provided with a hand grip exemplified by the slot or projection V to serve as a grip for being used manually while detaching the said module from the electric power circuit. The module M2 may also be provided with a hand grip, but this is not considered necessary, generally, since this will come into use only when the modules are required to be detached from each other; and such detachment can be done easily without needing a hand grip. However, such a hand grip for the module M2 may also be provided if necessity demands.
The terms and expressions herein are of description and not of limitation, and do not exclude any equivalents of the features illustrated and described, but it is understood that various other embodiments of the surge arrester device are possible without departing from the scope and ambit of this invention.
1. A surge arrestor device comprising first and second modules, the first module being fixed to one end of a power supply cable and the second module incorporating a arrestor; means for detachably attaching the said modules to each other, said modules whenever so attached, completing an electrical circuit within them, such that with the first module connected to an electric power source, power from the said source is transmitted by the circuit through the surge arrestor to the said cable.
2. A device as claimed in Claim 1 wherein the said modules are provided with electrical connectors for completing the circuit.
3. A device as Claim 1 or Claim 2 wherein the said means comprise a push-fit joint between the modules.
4. A device as claimed in any one of the preceding
Claims wherein a screw joint is provided between the
5- A device as claimed in any one of the preceding
Claims wherein visual/aural indicators are provided for indicating whether the surge arrestor is in operating condition or whether it is destroyed by a surge.
6. A device as claimed in any one of the preceding
Claims wherein visual/aural indicators are provided for
indicating a wiring fault.
7. A device as claimed in any one of the preceding
Claims wherein the first module is provided with a hand
8. A device as claimed in any one of the preceding
Claims wherein the second module is provided with a hand
|Indian Patent Application Number||986/MAS/2002|
|PG Journal Number||50/2007|
|Date of Filing||24-Dec-2002|
|Name of Patentee||TVS ELECTRONICS LIMITED|
|Applicant Address||JAYALAKSHMI ESTATES ,8 HADDOWS ROAD ,CHENNAI 600 006 ,|
|PCT International Classification Number||H01H 83/10|
|PCT International Application Number||N/A|
|PCT International Filing date|