So far we are doing is good ampermeter splicing meter, voltmeter and wattmeter directly. Splicing meter may only be applied at low loads. For high load where large phase currents and phase voltages are also possible, it is done in other ways that splicing meter indirectly. Splicing secar not directly performed by utilizing a measuring transformer consisting of current transformer and voltage transformer as shown in Figure 7:11.
Figure 7.11 Three-Phase Power Measurement with One Wattmeter in Indirect
Measuring transformer is a device that is very vital maid in indirect measurements. In practice, measuring transformers have been standardized, the secondary value of current transformer is 5 amperes and secondary values for voltage transformer is 100 volts. As for the primary grades are available in many price to meet the various needs of the electricity distribution network.
In indirect measurements, need to understand the correct polarity of tarfo measurement used. Error in determining polarity can cause failure in determining the value of the measurement. Therefore take note really polarity current transformer and voltage transformer.
Instruments for measuring electrical energy commonly known as energimeter. The instrument is also known as the watt-hour meter (Wh-meter). Energimeter an integration device. There are several types energimeter. Judging from the voltage source distinguished energimeter energimeter single phase and three phase. Measurement energilistrik become very important in the business world electricity.