How prepaid electric meters work?

Question

Hi

does anybody know how the prepaid electric meter works? i need to know the technical flow and all the possiblities of its implementation using a GSM network ( i am from a GSM operator). Its little urgent..anybody there to help me?

Answer 1

First, the meter installation needs an integral disconnect switch or a collar switch that mounts between the meter and the base. The switch can be activated from intelligence that is either internal to the meter, or via communications back to the "main office".

The account is credited with a certain dollar amount and the meter communicates usage to wherever the intelligence is housed (inside the meter or back to the main office). As the meter communicates the energy usage, the intelligence calculates the monetary value to be deducted from the credit. As the end user pays more, the account balance is credited (and perhaps communicated to the meter if the intelligence is internal to the  meter). As long as the account is continually credited to keep a positive balance, no action is necessary. If, however, the account's credit is depleted, the intelligence sends a signal to the disconnect switch to open, and optionally notifies the utility of the action.

Ideally, at intervals prior to disconnect, the system will warn the end user that only a short period of time is left before the credit is depleted; at least far enough in advance to allow for the user to contact the utility to arrange for additional credit.

With remote reconnects, it is important IMHO that the reconnect is not done remotely; the switch should be armed to allow reconnect, but the end user should then push a button to actually perform the switching operation. If the reconnect is done without the end user being prepared, there is a risk of fire should heat-generating equipment (stove, oven, space heater, etc.) comes on unattended with combustible materials nearby.