Q:What is the IEC 62052 11 standard?
Covers type tests for electricity metering equipment for indoor and outdoor application and to newly manufactured equipment designed to measure the electric energy on 50 Hz or 60 Hz networks, with a voltage up to 600 V.
Q:What is the EN50470-1 / EN50470-2 / EN50470-3 standard
3 specific European standards for active energy meters: EN50470-1 / EN50470-2 / EN50470-3. These standards specify the particular requirements and type tests for electrical energy meters. The EN50470-1/-3 standard defines three specific accuracy classes: A, B and C. These are comparable to the IEC62053-21/-22 active energy metering standard: Class A is equivalent to 2% accuracy, Class B to 1 % and Class C to 0.5 %.
Q:What is starting current of meter and what are the general minimum starting currents?
The starting current is the current value that determines the relevant characteristics of the meter, also called the calibration current value, which is determined by the starting current of the electric energy meter. Generally, the greater the multiple of the meter, the more accurate the measurement at low current. The multiple algorithm of the meter is based on the maximum rating. Current/basic current. That is, the current that the meter needs to reach when it starts. Generally speaking, there are 0.2%, 0.4%, 0.5%. Take the current of 10 (80) A, IB 0.5% as an example. The starting current of this electric meter is 10*0.5%=0.05, which means that the electric current must reach 0.05 before the electric meter starts to work and start measuring.
Q:What is the voltage (current) imbalance rate of smart energy meters?
In a three-phase power supply system, the voltage (current) unbalance rate is the difference between the maximum phase voltage (current) and the minimum phase voltage (current) as a percentage of the maximum phase voltage (current).
Q:What is the current imbalance of smart energy meters?
When any of the three-phase currents is greater than 5% of the rated (basic) current, the current imbalance rate is greater than the set current imbalance rate limit, and the duration is greater than the set current imbalance judgment delay , This working condition is current unbalance.
Q:What is the voltage imbalance of smart energy meters?
When any of the three-phase voltages is greater than the critical voltage of the energy meter, the voltage imbalance rate is greater than the set voltage imbalance rate limit, and the duration is greater than the set voltage imbalance rate judgment delay time, this This working condition is voltage unbalance.
Q:What is the critical voltage of a smart energy meter?
The minimum voltage that the smart energy meter can start to work is the critical voltage, which is generally 60% of the reference voltage. The critical voltage stipulates the minimum voltage for the smart energy meter to start work, which is the specified maximum limit, and the minimum power for the start work of the energy meter design can be lower than this value. Starting the work means that the energy meter can measure, display, and record events normally. It is not mandatory to respond to backlight lighting, communication, tripping, and alarm output. For three-phase energy meters, when the voltage of each phase reaches 60% of the lower limit of the reference voltage or when the single-phase voltage reaches 85% of the reference voltage, the energy meter can start working; for single-phase energy meters, when the voltage reaches When the reference voltage is 60%, the energy meter can start working.
Q:What is the reverse working condition of smart electric energy meter?
In a three-phase power supply system, when the direction of the total active power changes direction, at the same time, the active power is greater than the set active power reverse event active power trigger lower limit, and the duration is greater than the set power reverse event judgment delay time This kind of working condition is called power flow reversal.
Q:What is the power-off condition of smart energy meters?
The supply voltage of the single-phase energy meter is lower than the starting working voltage of the energy meter; the supply voltage of the three-phase energy meter is lower than the critical voltage of the energy meter, and the three-phase load current is not more than 5% of the rated (basic) current. This is called power down.
Q:What is the loss-of-current operating condition of smart electric energy meter?
In a three-phase power supply system, at least one of the three phases' load current is greater than the lower limit of the current trigger event, and the voltage of a certain phase is greater than the lower limit of the voltage trigger event, and the current of this phase is less than the set current trigger event. When the current triggers the upper limit value, and the duration is greater than the set delay time of the current loss event determination, this working condition is called the phase current loss.