Tampering Electricity Meter-Commonly used Tampering Techniques-Science Tips and Tricks

Significant and common techniques of tampering the electricity meter in household and industries.

CURRENT REVERSAL TAMPERING-
In this type of tampering, the polarities, neutral and phase are reversed. When this tampering is done, the rotor disk, instead of flowing in the forward direction tends to rotate in the reverse direction and hence, the units of power measured moves in the reverse direction.

In other words, the readings decrease, rather than increasing. Hence the units are manipulated and they display erroneous meter reading or low meter reading, than the actual amount of power consumed.

Current Reversal Tampering Detection Techniques:
The aluminum rotor disc present in the electricity meter runs in the clockwise direction as long as the neutral and phase connections are connected properly to it. But if these two wires are reversed, the meter starts to malfunction thereby rotating in the reverse direction there by leading to reduction in meter reading.

Hence to monitor the proper rotation of aluminum rotor disc and to avoid the current reversal tampering, a pair of LED and Photo-diode duo ( LED 1 and LED 2 ) are placed above and below the aluminum rotor disc as shown in the figure above.To let the light from LED fall on the photo-diode, a slot is cut on the aluminum rotor disc. When the disc rotates in clockwise direction, light from LED1 falls first on the Photo-diode 1 followed by the other, LED2 light falling on Photodiode 2. The output of the photodiodes are given to individual microcontroller ports with the help of a pull up circuit. As long as the sequence of LED1 and LED2 output enters the microcontroller, there is no tampering. If the order of photodiode output to the microcontroller is reversed, LED2 output reaching the microcontroller first followed by LED1 output, then there is the possibility of Current reversal tampering being attempted.

When the ports A and B respectively for Photodiode 1 and Photodiode 2 outputs are detected in order, two LEDs placed outside the electricity meter glow in order to indicate the perfect working of the electricity meter. When the ports are detected in reverse order, the LEDs glow in the reverse order as well, so as to indicate malfunctioning.As the rotor disc rotates in the opposite direction, the tampering information is sent to the micro controller. When micro controller receives the signals, it transfers it to the LCD and the GSM modem. So an information about the tampering that has occurred is displayed in the LCD, as well as sent to the electricity board through the GSM modem.Thus the tampering of the electricity meter using the current reversal technique is detected.


NEUTRAL TAMPERING-
As quoted, an electricity meter contains a voltage coil and a current coil. Both these coils should be properly energized for ensuring the rotation of disk. In this type of tampering, the neutral wire from the voltage coil is removed. When this is done, the rotation of the disk is hampered and it stops rotating, which in turn stops the rotation of the electricity meter. Hence irrespective of the amounts of power consumed, there is no account of the units consumed.

Neutral Tampering Detection Techniques:
This tampering is done by disconnecting the neutral wire in the domestic electricity meter. The circuit designed for the detection of neutral tampering is shown above.The component used for the neutral tampering detection circuit is an Optocoupler connected in parallel to the Voltage coil.The circuit works as follows. As long as the neutral and the phase are connected to the voltage coil, the parallely connected Optocoupler LED produces a high output thereby biasing the base of the photo transistor which produces an output at the emitter. This output is continuously monitored by the micro-controller.When the neutral wire from the electricity meter is disconnected, the power supply to the LED is also disconnected and hence it does not glow. As soon as the LED fails to glow, the photo-diode is unbiased and its output drops to low level or logic “0” signal and it sent to the micro controller. The micro-controller senses this change in optocoupler output and thus intimates the GSM modem to send a message to the Electricity board regarding the Neutral tampering.The micro controller is programmed using embedded C so as to intimate and transfer signals according to the signals received ( either “1” or “0”). When micro controller receives the signals, it transfers it to the LCD and the GSM modem. So an information about the tampering that has occurred is displayed in the LCD, as well as sent to the electricity board through the GSM modem.


MAGNETIC TAMPERING
When a magnet of sufficient strength is brought near the electricity meter, the field opposing the rotation of the aluminum rotor disc increases thus making the rotor disc run in slow pace or stop either. This type of approach to make the electricity meter malfunction by means of placing a magnet near the meter is Magnetic Tampering.

Neutral Tampering Detection Techniques:
Magnetic tampering technique is done by bringing a high powered magnet in close proximity of the domestic electricity meter. When this is done, the disc stops rotating. The circuit for the magnetic tampering detection circuit is as shown above.

The vital component used in the occurrence of the magnetic tampering technique in the domestic electricity meter is the Reed switch. The reed switch contains two magnetizable and electrically conductive reeds which have end portions separated by a small gap when the switch is open. The reeds are hermetically sealed in opposite ends of a tubular glass envelope.In the magnetic tampering technique, a high power magnet is brought in contact with the electricity meter. When this happens, the rotor disc is exposed to a high magnetic field. Then the resultant opposing magnetic field to the rotor is highly increased leading to slowing down of rotor or perfect stopping of the disc rotation. The electricity meter is thus manipulated and ultimately power is consumed without being paid for.

Now when a reed switch is placed on the electricity meter and is connected to the micro controller, the magnetic tampering can be effectively identified. When a high power magnet is bought in proximity of the electricity meter in the presence of the Reed switch two leads come in contact with each other and result in the closed circuit thereby helping in detection of the signal by the micro controller. Thus the tampering is detected.

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Post a Comment

  1. Your tips that you shared on your blog is really important for some troubleshoot. But if I can't fix it on my own, I always contact this Electrical Contractor in Gold Coast. I choose them because they are the best in our place. If you need also their services, you can visit their website here.

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  2. We appreciate our Readers feedback......

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  3. Hi dear I am using digital electric meter in my house showing readig on a digital display. How can I hack to spin back at least 1000 units. Waiting for reply

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    Replies
    1. Dear mohsin first thing first " This Blog does not encourage/suggest/engage in tampering your electric meters".This post is for knowledge gain for Engineering/Science students.We hope our readers to be law abiding citizens of their country.

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