State and explain any four commercial losses in transmission and distribution system.
Commercial losses in Transmission & Distribution systems: i) Power Theft ii) Unmetered supply iii) Meter inaccuracies. iv) Metering discrepancies. v) Small unmetered loads. vi) Billing issues vii)Lower collection efficiency.
i) Theft of electricity: Theft of electricity has been carried out by the ways of meter tempering and direct hooking. In meter tampering various methods have been carried out such as placing the powerful magnet on the meter, bypassing of meters, disturbing the disc rotation by inserting some material externally, stopping the meter by remote control, change in meter terminals etc. In direct hooking tapping of conductor of LT feeder or tampered service to make unauthorized and unmetered supply available for them. Power tapped by direct hooking can’t be accounted as it is an unmetered consumption.
ii) Unmetered supply: Unmetered supply used by agriculture pumps is one of the major causes of commercial loss for most of the states. Agriculture tariff is such that it charges consumption per unit of HP of the motor. State government gives subsidy on agricultural consumption hence some utilities deliberately overestimates this unmetered consumption.
iii) Meter inaccuracies: Losses due to meter inaccuracies are nothing but a difference between actual energy supplied to consumer through the meters and amount registered by meters.
iv) Metering Discrepancies: Meter to be used for the measurement of electrical energy should be properly calibrated before installation. Defective meters give rise to errors in energy reading, these defects may be due to multiple reasons such as burning of meters, heavy load lead to burning of terminal box. Recording may also be reduced due to wrong CT ratios.
v) Small unmetered loads: In some sections, energy consumption or usage is estimated in place of measuring it with an energy meter, this gives rise to unmetered losses. This happens in street lightning.
vi)Billing issues: This is regarding consumer complaints regarding bill not received, late receipt of bill, received wrong bill, different meter reading, wrong applied tariff, wrong calculations.
vii) Lower collection efficiency: Most of the times utility fail to collect the actual amount billed by them. So it is well obvious that higher commercial losses are inherent to lower collection efficiency.