The first step in raising this question is to roughly estimate whether the user's electricity consumption has indeed exceeded the full load of the meter (4.4kw for single-phase 5 (20) A, 8.8kw for single-phase 10 (40) A, 26.4kw for three-phase 10 (40) A, and 52.8kw for three-phase 20 (80) A). If so, as long as the user reduces the load, the electricity meter will automatically close for power supply after 5 minutes. If not, then the user needs to be stuck in the electricity sales system to read the card and see if the load limit was reduced during the last purchase of electricity (if the user's meter has not been overloaded for a long time, and suddenly experiences an "overload" power outage without adding more electrical equipment, which often occurs a few days after purchasing a new electricity card, this is often the reason). If the limit is indeed reduced, then only one more purchase of electricity is needed for the user card, and the "maximum load" will be increased when purchasing electricity. Here, it should be noted that there is a misunderstanding among electricity salespeople that setting the "maximum load" to "0" means no longer limiting the load (thinking it is "full load"). Actually, setting it to "0" means the minimum load, and once electricity is used, it will trip due to overload. In addition, for a mutual inductance meter, its maximum load should be the product of the maximum load of the meter itself (3.3kw) and the transformer multiplier. For example, if the negative inductance is a multiplier of 100/5, the maximum load is 3.3 × 20=66kw. This will be defaulted by the system when issuing new cards. However, starting from the second purchase of electricity, the system no longer uses the default value. If accidentally operated, the load value may be set too low, causing overload tripping.

If none of the above methods can solve the problem of "overload tripping", it is possible that the user's card is broken and cannot write values in the data area of the maximum load. Therefore, a new card can be used to replace the meter, inserted into the meter once, and then purchased electricity. Finally, the maximum load can be reset.