TAMPER DETERRENT SINGLE PHASE ELECTRICITY MEASURING
SYSTEM AND METER
FIELD OF THE INVENTION
[0001] The present invention relates to generally to devices for preventing electrical meters from being tampered with and, more particularly, to an electricity meter system.
PRIOR ART
[0002] The function of Meter is to record & indicate the energy consumption through either electromechanical counter or Liquid Crystal Displays. The meter may have inbuilt provisions to detect & record various types of tamper attempts. Further meters are sealed at appropriate points after installation to prevent tamper. In addition, the meters are generally installed inside a sealed box to prevent the tamper attempts. Conventional electrical meters and various other kinds of meters are sealed in an enclosure from which readings can be taken without removal of any parts of the meters.
[0003] Even after ensuring above mentioned practices the meters may get tampered through use of new tampering tools and methods. Therefore a new concept is being tried out by electrical distribution utilities to minimize the meter tamper attempts. The concept is to split or separate the Energy display from the rest part of the meter i.e. having 2 physically separate units or modules. The Display Module is to be installed inside consumers premise whereas the Metering Module will be installed on the power line distribution pole at a sufficient height so that access by human beings will be difficult. The electrical connection cable carrying power to the consumer starts from the Distribution pole & passes through Metering Module finally terminating in consumer Premise.
[0004] The mounting of Metering Module at a certain height on the pole will add additional barrier to tampering. Further, many such Metering Modules, each separate for corresponding consumer, can be installed together in the form of a cluster inside a box. This box provides protection against dust, water, sunlight etc.

Sealing & locking of this box will further add barrier to tampering. This box may have one additional Module having some form of Display. This additional Module will collect & show consumption information from individual Metering Modules mounted in the Box. In such arrangement the Metering Modules need not have display on it.
[0005] The metering Module will communicate the energy count recorded by it to the display module through some form of communication. The consumer will be able to read the energy count through the Display Module available in his premise. [0006] Conventional metering module incorporates terminals for terminating the service wire originating from distribution pole as well as for fixing the service wire going to the consumer premise. This arrangement requires that service wire be cut at the metering module terminals. Also, it requires that the metering module to have specific elements such as copper conductors in the form of wires or rods or bars, inside it to connect incoming terminals i.e., terminals where wire originating at distribution pole terminates with outgoing terminals i.e. terminals where wire going to consumer premise is fixed. The specific elements are required for detecting the voltage and current values. Since the service wire carries a large amount of current, the joining between the elements and the service wire has to be fight and is generally performed using screws. The cutting of wire, insertion of an extra element, and joining the elements with the wire adds on to the material cost and the time for assembling the metering module.
[0007] Therefore, there is a need for a metering system, which is substantially tamper proof and uses a metering module which saves cost and takes lesser time for assembly.
SUMMARY OF THE INVENTION
[0008] An objective of the invention is to provide an electric metering system which obviates the need to cut service wires.
[0009] Another objective of the invention is to reduce the time required to installation of a metering module of the electric metering system.

[0010] Yet another objective of the invention is to reduce the cost of the metering module of the electric metering system.
[0011] Yet another objective of the invention is to improve the sealing of the metering module so as to make the metering module tamper proof [0012] Accordingly, the present invention provides an electric meter system for measuring electric energy value consumed by a consumer in a single phase electricity supply comprising a metering module having a current transducer assembly having a cylindrical pipe carrying current for measuring curunt value. A printed circuit assembly for measuring energy value is provided, wherein the printed circuit assembly has a plurality of screws pierced into a phase wire and a neutral wire of a service wire of the single-phase electricity supply for tapping a voltage value. The screws are being held using tapping conductor, for example, brass plates, means for receiving the current value from the current transducer assembly, and a computation logic module for computing the energy value based on the current value and the voltage value; and a metering module enclosure for housing the current transducer assembly and the printed circuit assembly. [0013] Thus, according to the electric meter system provided by the invention, the need to cut the electricity supply wire is obviated and therefore the cost of the metering module and the time required to assemble the metering module is reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to various embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. [0015] Fig. 1 shows an electricity meter system, in accordance with an embodiment of the invention.

[0016] Fig. 2 shows internal constructional details of the metering module of the
electricity metering system, in accordance with an embodiment of the invention.
[0017] Fig. 3 is a front view of the metering module of the electricity metering
system, in accordance with an embodiment of the invention.
[0018] Fig. 4 is an isometric exploded view of a printed circmt ass».mbly of the
metering module, in accordance with an embodiment of the invention.
[0019] Fig. 5 is an isometric exploded view of a current transducer of the metering
module, in accordance with an embodiment of the invention.
[0020] Fig. 6 and 7 depict a method to assemble the metering module, in
accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF INVENTION
[0021] Various embodiments of the invention provide an electricity metering system which obviates the need to cut the electricity supply wire for measuring the energy consumption.
[0022] Fig. 1 shows an electric meter system 100, in accordance with an embodiment of the invention. System 100 shows an electricity pole 102, users 104, loads 106, and a metering module box 108. Electric pole 102 supports the main electrichy supply cables and provides electricity supply to users 104 through supply cables 110. Users 104 may be houses or a commercial premises which use the electricity supplied to feed loads 106. Metering module box 108 includes a plurality of metering modules 112. For example metering module box 108 includes metering modules 112a, 112b, and 112c. Metering module 112 measures the amount of energy consumed by users 104. Each user 104 may have a dedicated metering module. For example, metering module 112a is dedicated to user I04a. A detailed description with respect to the internal construction of metering module 112 has been given with reference to figure 2. Fig. 2 shows internal constructional details of metering module 112 of electricity metering system 100, in accordance with an embodiment of the invention. Metering module 112 includes a plurality of current transducer assemblies (CT) 202, a printed circuit assembly (PCA) 204, and a metering module enclosure 206. Fig. 2 also shows supply cable 110 with a phase

wire llOp and a neutral wire llOn going into metering module 112. Metering
module enclosure 206 is a transparent box with all side closed except one edge
from where the electronics hardware is inserted inside enclosure 206.
[0023] CTs 202 measure cunent passing through phase wire 1 lOp and neutral wire
1 lOn and sends a current value to PCA 204. PCA 204 has a plurality of screws 208
for tapping a voltage value between phase wire 11 Op and neutral wire UOn.
Screws 208 pierce into phase wire 11 Op and neutral wire UOn. Screws 208 are
held using a plurality of soldered tapping conductor, for example, brass plates 210.
PCA 204 also has means for receiving the current value from CT 202. PCA 204
uses a computation logic for measuring the energy value consumed uased on the
current value received from CT 202 and the voltage value. The metering module
enclosure 206 houses CT 202 and PCA 204.
[0024] In accordance with an embodiment of the invention, metering module 112
also includes a cover 212 for enclosing screws 208. Cover 212 has means for
sealing cover 212 with metering module enclosure 206.
[0025] In accordance with an embodiment of the invention, electric meter system
100 further includes a display module 114 (shown in Fig. 1) installed at user
premises for displaying the energy value as computed by metering module 112.
For example, display module 114a (shown in Fig. 1) at user 104a displays the
energy value as calculated by metering module 112a for load 106a.
[0026] In accordance with an embodiment of the invention, electric meter system
100 further includes a metallic bracket 302 as shown in Fig. 3. Metering module
112 is fixed on metallic bracket 302. Fig. 3 also shows a spring operated holding
part 304 for mounting and adjusting metering module 112. Spring operated holding
part 304 is on the enclosure and holds the metering module 112 with bracket 302
firmly.
[0027] Fig. 4 is an isometric exploded view of PCA 204 of metering module 112,
in accordance with an embodiment of the invention. PCA 204 has-a LED 402 for
indicating the rate of energy consumption (kWh), and two LEDs 404 forming the
parts of optical communication port. Fig. 4 also shows tapping conductor, for

example, brass plates 206 and illustrates the method of mounting the same on PCA 204.
[0028] Fig. 5 is an isometric exploded view of CT 202 of metering module 112, in accordance with an embodiment of the invention. Cylindrical pipe 502 running through the center of CT carries the current.
[0029] In accordance with an embodiment of the invention, electric meter system 100 includes an optical communication port. The optical communicauon port has means for calibrating and initializing metering module 112, and means for collecting data related to energy consumption.
[0030] Fig. 6 and 7 depict a method to assemble metering module 112, in accordance with an embodiment of the invention. CT 202 and PCA 204 are inserted in a main assembly of metering module 112. Once CT 202 and PCA 204 are inserted, removing them or accessing them is not possible without breaking metering module enclosure 206. Phase wire 11 Op and neutral wire 11 On inside electrical connection cable are inserted inside metering module 112. Subsequently, screws 208 are tightened to connect metering module 112 to phase wire 11 Op and neutral wire 1 lOn and cover 212 is fixed to deter the access to screws 208. The free ends of phase & neutral wires 110 are clamped using lugs. A Hologram sticker is placed at required point on enclosure 206. Using the sealing arrangement provided on the metering module, cover 212 is sealed with enclosure 206. Metering Module 112 is then mounted on metal bracket 302 just by placing on it. Spring operated part 304 on enclosure 206 holds the metering module 112 with metal bracket 302 firmly. Once inserted the Metering Module holds the bracket & remains fixed with it.
[0031] In accordance with an embodiment of the invention, the plurality of metering modules is installed in the form of a cluster inside metering module box 108. Many metering modules, each separate for corresponding consumer, can be installed together in the form of a cluster inside a box. This box provides protection against dust, water, sunlight etc. Sealing & locking of this box will further add barrier to tampering. This box may have one additional module having some form of display. This additional module will collect & show consumption information

from individual metering modules mounted in the box. In such arrangement the Metering Modules need not have display on it.
[0032] The construction of metering module 112 requires passing of electrical connection wires 110 from pole 102 to load 106 inside consumer nremise 104 directly through it. Due to this feature, the need to use high current-carrying conductors inside metering module is eliminated, resulting in cost reduction. [0033] As the electrical connection wires directly pass through the Metering Module, the need of incorporating conventional terminal block with required current carrying capability is eliminated, resulting in further cost saving. [0034] As the electrical connection wires directly pass through the Metering Module, the conventional practice of cutting the wires, then fixing them with metering module using screws is eliminated, resulting in reduction in time required during installation of metering module till providing the electrical connection to the consumer.
[0035] The plastic parts forming the enclosure of Metering Module are fixed with each other using press fit arrangement, i.e. eliminating the use of screws. The metering Module requires no Screws during assembly operation. All assemblies are fixed just by press & fit approach. This leads reduction of complete metering module assembly time, Once fixed, the enclosure parts are interlocked with each other. This interlocking cannot be removed unless the enclosure is broken. Such arrangement avoids the need of using screws & ultrasonic welding which is conventional practice of locking parts with each other.
[0036] The enclosure of metering module is a transparent box with all side closed except one (i.e. the edge from where the electronics hardware is inserted inside the enclosure). Such construction provides improved level of protecfion against dust & water seepage inside the enclosure. The screws used for sensing of voltage between phase & neutral wires, are tightened during installation of metering module. A separate cover is provided with metering module to enclose these screws. In addition, this cover is with sealing arrangement to seal the cover with metering module enclosui-e. Such design prevents the attempt to tamper the metering Module.

[0037] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

We claim:
1. An electric meter system for measuring electric energy value consumed by
a user in a single phase electricity supply, the electric meter system
comprising a plurality of metering modules, each metering module
comprising:
a. a plurality of current transducer assembly for measuring current
value, the current transducer assembly having a cylindrical pipe
carrying current;
b. a printed circuit assembly for measuring energy value, the printed
circuit assembly having:
i. a plurality of screws for tapping a voltage value between a phase wire and a neutral wire of a service wire of the single phase electricity supply, the screws being pierced into the phase wire and the neutral wire, the screws being held using tapping conductor;
ii. means for receiving the current value from the current transducer assembly; and
iii. a computation logic module for computing the energy value based on the current value and the voltage; and
c. a metering module enclosure for housing the current transducer
assembly and the printed circuit assembly.
2. The electric meter system of claim 1, wherein the plurality of metering modules is installed in the form of a cluster inside a metering module box.
3. The metering module of claim 1 further comprising a cover for enclosing the screws, the cover having means for sealing the cover with the metering module enclosure irreversibly.
4. The electric meter system of claim 1 further comprising a display module, wherein the display module displays the energy value as computed by the computation logic embedded in metering module, the display module being installed at the user premise.
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5. The electric meter system of claim 1 further comprising a metallic bracket,
the metering module being fixed on the metallic bracket.
6. The electric meter system of claim 1 further comprising a LED on metering
module for indicating the rate of energy consumption as computed by
energy computation logic.
7. The electric meter system of claim 1 further comprising an optical communication port, the optical communication port has means for calibrating and initializing the metering module, the optical communication port further has means for collecting data related to energy consumption.
8. The electric meter system of claim 1, wherein the metering module is installed at a height on an electricity supplying pole.
9. A method for assembling a metering module of an electric meter system,
the method comprising the steps of:
a. inserting a current assembly and a printed circuit assembly in a
main assembly of the metering module.
b. inserting a phase and neutral wire into the metering module;
c. tightening screws to connect the phase and neutral wire to the
metering module.
d. fixing a cover for deterring access to the screws, wherein the cover
is fixed by press fitting, the cover locking with the metering module
irreversibly;
e. clamping free ends of the phase and neutral wires using lugs; and
f. mounting the metering module on a metal bracket.

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