What are two parts of kilowatt hour ammeter?

Answer 1

Most important part is the shunt. It diverts most of the current around the meter. They used to be 50 micro amp meter movements. They were 100 microamp movements with a resistor that matched the meters coil resistance and split the meter current. That is they fully deflect when 50 microamps is flowing through the coil of the meter movement. Electronic ones still have a shunt. It is basically a piece of metal used as a resistor. The resistors value determines the amount of current it will pass according to Ohms law. The full range current used in the calculation. "Amps equals voltage divided by resistance". "Resistance equals voltage divided by current". That would give you the full resistance. You calculate the 50 microamps and subtract its resistance and use the remainer as your shunt value. Part 1: Shunt Part 2: Meter That is an ampmeter. A watt meter is a combination of an ampmeter and a voltmeter. Ohms' Law applies strictly. You feed the amps and voltage to the meter movement ( now LCD display) and it "does the math" and displays in watts. Curent in amps is measured is series and volts are measured in parallel with the source. Voltage times amps equals watts. One kilowatt at standard household voltage of 115 volts A.C. is about 9 amps.