energy meter
energy meter
(OP)
an energy meter (kWhr) with the following name plate spec.
Current 5000:1 A
Voltage 10.5 kV/sqrt(3) : 100V/sqrt(3)
is fed from voltage and current transformers with following spec.
VT :10.5 kV/sqrt(3) : 110V/sqrt(3)
CT :5000:1 A
what will be the error in the meter reading due to voltage difference
Current 5000:1 A
Voltage 10.5 kV/sqrt(3) : 100V/sqrt(3)
is fed from voltage and current transformers with following spec.
VT :10.5 kV/sqrt(3) : 110V/sqrt(3)
CT :5000:1 A
what will be the error in the meter reading due to voltage difference






RE: energy meter
respectfully
RE: energy meter
Multiplier would generally be CT ratio times VT ratio.
RE: energy meter
the case is that meter and VT secondary spec. are different!
RE: energy meter
respectfully
RE: energy meter
RE: energy meter
The actual installed IT xmfrs are providing 5000/1 * 10500/110, or a multiplier of 477,272.7.
So the meter is observing 545,000/ 477,272 of the anticipated energy (i.e the secondary amounts are LARGER than expected), which obviously simplifies to 110/100, or 10% too much.
edit: I missed the sqrt(3) bit in your OP, but as it applies to both VTs, the ratio still holds. Just divide my multipliers by sqrt(3) if you need the exact numbers for some reason.