The accuracy of electricity meters relies on two core indicators: anti-creep and starting current. One ensures the meter doesn't register consumption when there's no power, and the other controls the precision of measuring even small amounts of electricity. This is like a precisely controlled dual valve, safeguarding the accuracy of every kilowatt-hour measured.
Anti-creep prevents the electricity meter from "running idle." When there is no load current in the circuit and only voltage is applied, if the meter shows slow movement or pulse flashing, this is a creep phenomenon.
This is similar to a stationary bicycle inexplicably rolling away, often caused by circuit interference or component errors – mechanical meters experience additional torque due to asymmetrical magnetic flux, while electronic meters may misinterpret weak interference signals as power consumption.
According to the national standard GB/T 17215.211-2021, an electronic meter should not generate more than one pulse in one hour without a load, and the rotating disc of a mechanical meter should not rotate more than one revolution. This can be effectively avoided through techniques such as software filtering and electromagnetic braking.
Starting current is the minimum current value at which the electricity meter can begin continuous rotation (or pulse output), and it is a core indicator of the meter's sensitivity. Below this current, the meter cannot recognize the power consumption signal.
For example, a household Class 1 single-phase electricity meter typically has a starting current of no more than 0.4% of the basic current. For a 5(60)A meter, the starting threshold is only 0.02A, ensuring that even small loads from devices like routers and set-top boxes in standby mode are accurately recorded, preventing electricity bill losses.
These two aspects seem independent but are actually complementary. Excessively increasing the starting current sensitivity can easily lead to creep; strengthening anti-creep capabilities may raise the starting current "threshold." Modern electricity meters use algorithms to dynamically balance these factors, accurately filtering out false interference signals while simultaneously capturing weak effective currents.