Bagaimana cara memilih meteran pintar-fase tunggal?
Penggunaan meteran pintar-fase tunggal terutama digunakan pada meteran listrik rumah tangga. Biasanya meteran rumah tangga dipasang oleh departemen listrik atau pengembang, tetapi ada tempat di mana meteran fase-tunggal harus dipasang untuk mengukur meteran perumahan atau sewaan. Jadi, inilah cara memilih smart meter-fase tunggal agar dapat digunakan di masa mendatang.
1. Konfirmasi jangkauan
Mengapa rentang meteran pintar-fase tunggal harus dikonfirmasi terlebih dahulu? Untuk penggunaan yang aman di masa mendatang, harus dipastikan bahwa arus pengukur yang diukur tidak melebihi nilai yang diukur. Konfigurasi meteran pintar-fase tunggal harus didasarkan pada kekuatan utang. Arus peranti fase-tunggal adalah 4,5A per KW, sehingga rentang meteran harus dikonfigurasi menjadi 1,2-1,5 kali arus. Jika daya total peralatan rumah tangga adalah 4KW dan arusnya 18A, meter energi listrik fase tunggal 5(20)A dapat digunakan.
2. Konfirmasi kapasitas
The typical voltage specification of a single-phase smart meter is 220V, and the current specification is 1.5(6)A 5(20)A 5(60)A 15(60)A 20(80)A, etc. The choice of specification at this stage is mainly based on the user's load. Usually, the upper limit of the load current cannot exceed the rated current of the electric energy meter, and the lower limit is not less than the load current specified within the allowable error range of the electric energy meter. For example, the total power consumption of the user is about 10KW, the voltage is 220V, and the current is 10000÷220≈46A. That is to say, the power is divided by 220, which means that a certain margin is fully considered, and the current value is about 46A. You can choose the current specification of 5(60) 15(60)A. You can also choose a smaller current size and connect a current transformer.
3. Selection of current transformers Current transformers are specially designed for high current users. It is capable of converting large currents with larger values to secondary currents with smaller values for safeguard and measurement purposes. For example, a 100/5 current transformer can convert 100A to 5A of current. The selection of current transformer specifications is mainly for low-voltage users. Low-voltage users may not be able to estimate power consumption due to random load variations. Therefore, the transformer specifications are not fixed. It is usually calculated based on known power. For example, for a user with an electric power of 100KW, the voltage is 220V, the current is equal to 100000÷220≈455A, and a certain margin needs to be considered. A 500A current transformer must be selected. The secondary output current of the transformer is usually 5A, so we choose a 500 to 5 transformer. The accuracy of the current transformer must be at least the same as the meter.
