Ratio:400:5 A. This means that when 400 amps of current flow through the primary winding, 5 amps are induced in the secondary winding.
Phase:Single-phase.
Basic Impulse Level (BIL):10 kV. This is the maximum transient overvoltage the transformer can withstand.
Frequency:50/60 Hz.
Metering Class:0.3 B0.2. This specifies the transformer's accuracy for metering purposes.
Rating Factor:2.0. This indicates the allowable continuous current as a multiple of the rated current without exceeding the specified temperature rise.
Functional use
Instrument transformers are high-accuracy electrical devices used to:
Safely isolate metering and control circuits from high-voltage or high-current power circuits.
Step down a large primary current to a small, measurable secondary current for monitoring and protection devices
