Intelligent Controller
26
9 Appendix A: Selection of KWH Meter & Current
Transformer
Selection scheme 1
KWH meter model: ENTES EPR-04S-96
Parameters of ENTES EPR-04S-96
（
1
）
Measure the 3-phase voltage and electric current. Calculate the forward and
reverse active electricity quantity.
（
2
）
Working voltage: 45-265V AC/DC.
（
3
）
Measuring voltage: 10-300V AC (L-N), 10-500V AC (L-L).
（
4
）
Frequency: 45-65Hz.
（
5
）
Reference current: 0.05-5.5A.
（
6
）
Communication port: RS-485 port.
（
7
）
Communication protocol: Modbus RTU.
Current transformer: comply with the following parameters.
Parameters of Current Transformer.
（
1
）
Rated voltage & frequency: 630V, 50Hz.
（
2
）
Grade of accuracy: 1.
（
3
）
Secondary rated current: 5A.
（
4
）
Rated output load: 5VA.
（
5
）
Rated primary current of current transformer: Select according to table 1.
Please use the current transformer made by a well-known brand with high
reliability.
Table 1: Reference Table of Load and Mutual-Inductance Ratio
Rated capacity of unit (HP)
Rated capacity of unit (kW)
Mutual-inductance ratio of current
transformer
≤18
≤50.4
50/5A
20~36
56~101
100/5A
38~74
106.4~207.2
200/5A
76~88
212.8~246.4
250/5A
Selection scheme 2
KWH meter model: Wattnode Modbus WNC-3D-240-MB
Parameters of WNC-3D-240-MB:
（
1
）
Measure the 3-phase voltage and electric current. Calculate the forward and
reverse active electricity quantity.
