TAMPERPROOF ENERGY METERS AND METERBOXES

Er. K.V. SURYA PRAKASA RAO

Energy Meters play the vital and important role of measuring the energy consumed by various categories of consumers and these are an important link in revenue collection of any Electrical Utility / Electricity Board.

It is understood -:hat energy meters currently available in the market can be tampered with and some of the unethical consumers employ ingenious ways to tamper with calibration of the meters, steal energy and do not pay.for the energy consumed by them. This results in a loss of revenue which is an important contributory factor in the smooth and profitable functioning of any Electrical Utility..

THE SALIENT FEATURES OF SUCH A TAMPER PROOF ENERGY METER ARE

The Energy Meter is “IS!” marked as per IS : 13010 :1990. 2. The Energy Meter meets the requirement of Accuracy Class 23. The casing of the meter is fully transparent and made out of Ultra-violet

stabilized Polycarbonate material, resulting into :a} fully transparent polycarbonate meter base. b) fully transparent polycarbonate meter cover.c) fully transparent polycarbonate terminal cover.4. The meter cover and meter base have press fit arrangement, so that the

meter can be closed by simply pressing the meter cover on the meter base i.e. the meter cover gets self locked to the meter base. Additionally, the meter cover is ultrasonically welded to the meter base, so as to avoid insertion of any foreign material inside the meter, with an intention of tampering with it.

5. The Terminal Block is made out of Glass Filled, Fire Retardent Engineering Plastic material, capable of withstanding Glow Wire Test at a temperature of 960° C.

The fully transparent polycarbonate terminal cover also has self locking / press fit arrangement with the terminal block. After installation of the meter at the consumer’s premises, the terminal cover is simply pressed and it gets self locked. Thus the connection at the terminal block cannot be tampered with by “ the consumer.

With this arrangement, the self locked and ultrasonically welded meter can only be broken open.

06.As an additional precaution to avoid tampering, there is provision for sealing the meters with lead wire seal.

07.The meter is provided with unidirectional counter so that the meter reads only in the positive direction, even if the direction of rotation of the disc is reversed by reversing the connections.

08. in order to reduce the frictional losses as also the wear and tear of the moving parts, resulting into increased the life of meter, Magnetic Suspension Bearing is provided in the meter.

O9. In order to reduce the apparent power loss, the burden of the re-designed Potential Coil has been has been reduced from 6VA to 4VA.

10.The Current Coil burden has also been reduced from 2.5VA to 0.4VA11.100% meters are tested on computerized test benches with printout facility,

using Class 0.1 Electronic Reference Standards, in air-conditioned environment.

12. DVB witnesses the testing of 100% meters at the time of inspection.

13.Meters are guaranteed for 10 years satisfactory performance.

TAMPER PROOF METER BOXES

It is widely known and has been reported that even the Tamper Proof Energy Meters -both Static and Electro-mechanical - are prone to tampering and can be tampered with by employing ingenious ways, resulting into loss of revenue and endangering the smooth and profitable working of any Power Utility. The solution lies in installing the meters in a tamper proof enclosure at the consumers premises

CHOICE OF TAMPER PROOF METER BOXES

It is understood from the technical specifications of Meter Boxes from various State Electricity Boards that the SEB’s are procuring three (3) types of Meter Boxes :

a) Fabricated Mild Steel Meter Boxes.

b) Deep Drawn Mild Steel Meter Boxes.

c) Moulded Engineering Plastic Meter Boxes.

SALIENT FEATURES OF TAMPER PROOF METER BOXES

The various desired / implied anti-tamper features have been considered while designing the tamper proof Meter Boxes and the salient features of Tamper Proof Meter Boxes are as under:

• Tapered Roof, so that water does not stay at the top.• Toughened Glass / Transparent Engineering Plastic viewing window

for meter reading.• Glass fixing from inside only with metal supporting clamps.

Replacement possible only on opening the door, after breaking the seals.

• Cable entry & exit through cable glands, not openable from outside.• Two door hinges, fitted from inside and not approachable from

outside,• For locking & sealing the cover with base, two nos. U-Shaped latches

provided.• Provision for Padlock for additional sealing.• For ease of wiring, meter mounting portion raised by about 10 mm.• Provision for holding Meter Reading Card.• Customer’s special requirements can be complied with.