1. Pre-alarming: When the remainder is less than alarming limit, first the out relay will cut off load, when IC card is set inside the meter, which can re-work and the LED always lights to remind the user to purchase power timely, and the meter will cut off till remainder is over.
2. Load control: When the load is beyond the setting value, the relay inside the meter will cut off load automatically to remind the user. In this case, meter can re-work by reducing load and re-insetting the card
3. Self-checking breakdown: A meter can self-check IC card, LED display, relay, etc.