THIS is with reference to the letter ‘Low voltage’ (June 30). The writer claims that owing to low voltage consumers have to pay 50 to 60pc more charges as the number of amperes increases due to low voltage.

The fact is electricity is charged on the basis of wattage (which equals volts multiplied by amperes) and not amperage. An airconditioner which consumes 1.5 kw will use 1.5 units every hour, even if the voltage is low and the amperage high.

Moreover, in many countries, like the United States, the supply voltage is 110 (not 220, as in Pakistan) and the amperage is twice that in Pakistan. But a 1.5 kw airconditioner in the US still consumes 1.5 units every hour, as consumption depends upon the wattage and not the amperage.

The writer, however, should have mentioned the damage caused to appliances by low voltage.

S. Lakhani

Karachi

Published in Dawn, July 8th , 2014