The function of a neutral earth resistor is to limit any fault current resulting from fault between a line conductor and earth.
Resistor
Yes, when using a step down transformer the amperage is affected.
A variable resistor means that the resistance can be varied, usually by using a slide. A fixed resistor can not be varied.
If these are the exact voltages that you need you will need an auto transformer to obtain these voltages. If these voltages are nominal voltages and are of a three phase four wire configuration, the 220 voltage can be obtained from the three phase legs to the neutral (ground) connection. The equation to use is 400/1.73 = 231 volts.
It depends on where you are going to use this resistor and what its application going to be. If the circuit you are using can tolerate this then you are fine.
by using a resistor or capacitor or transformer
Neutral Ground Resistor is using for minimizing the fault current of system. It is a resistor which connected between ground and neutral and increase the resisting path for fault current.
an REF relay (restricted earth fault) is used to provide ground fault protection for a transformer. Its' operation is limited by CTs starred towards the transformer (usually on the transformer bushings or in breakers used to isolate the transformer), so it will only operate for transformer related faults. Because of this, it can be set to operate very quickly.
Resistor
You can use a transformer to decrease the voltage from 8000 volts to 800 volts. By using a transformer with a turns ratio of 10:1, you can step down the voltage while maintaining the same frequency. This will help in reducing the voltage safely and efficiently.
You would not connect a current transformer to a 230 v supply. To get 5.6 v 12 mA you could get a 230 to 6 volt transformer, then drop the supply from 6 to 5.6 using a 33-ohm resistor.
Yes, when using a step down transformer the amperage is affected.
using a variable resistor we can adjust the sensitivity of a light dependent resistor
A variable resistor means that the resistance can be varied, usually by using a slide. A fixed resistor can not be varied.
if you want to find the current (in amperes) through the resistor then connect a ammeter in series with the resistor.
yes you can! you can use a multimeter and a resistor.
If these are the exact voltages that you need you will need an auto transformer to obtain these voltages. If these voltages are nominal voltages and are of a three phase four wire configuration, the 220 voltage can be obtained from the three phase legs to the neutral (ground) connection. The equation to use is 400/1.73 = 231 volts.