what is differance betbeen RVT & PT 11 KV
This is really a question for the "Electrical Engineering" Section of CR4.
Depending on the customary description, originally British or USA practice, VT = Voltage transformer and PT = potential transformer both mean an instrument transformer which accurately transforms the voltage between some places in a high voltage installation to 110 [British] or 120V [USA] for a given High Voltage; e.g. for 11 kV to 110 V the instrument transformer would have 100:1 ratio or 14400/120V with 120:1 ratio
RVT has no standard meaning - it can even mean "Rotary Voltage Transformer" which actually meant a DC commutator rotating motor-generator which took 28 VDC from an aircraft battery and gave 250 VDC out.
In a place where PT means an instrument voltage/potential transformer, RVT may mean a transformer of moderate size with a secondary low voltage resistor load which is has the purpose of giving a resistive load at the high voltage side for earthing/grounding reasons. If it were a grounding transformer, it would usually have an earth symbol connected to one end of the HV winding.
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