×

# CT Apparent Burden Problem

1. ## CT Apparent Burden Problem

A watt-hour meter draws 1.5 watts and 11.3 Vars from a potential transformer, and 1.88 watts and 1.8 Vars from a current transformer, the total apparent burden placed on the current transformer is?

Explain the concept of this "apparent burden" problem.  Reply With Quote

2. Originally Posted by dukeofsmooth A watt-hour meter draws 1.5 watts and 11.3 Vars from a potential transformer, and 1.88 watts and 1.8 Vars from a current transformer, the total apparent burden placed on the current transformer is?

Explain the concept of this "apparent burden" problem.
Burden is shown as apparent power (S or VA). Thus to calculate the total apparent burden placed on just the CT, we need to convert watts and vars to VA.
S^2=P^2+Q^2
S=sqrt((1.88 Watts)^2+(1.8 Vars)^2) = 2.603 VA

That's my best guess at the answer, seems to simple to be right though.  Reply With Quote

3. Originally Posted by Kalbi_Rob Burden is shown as apparent power (S or VA). Thus to calculate the total apparent burden placed on just the CT, we need to convert watts and vars to VA.
S^2=P^2+Q^2
S=sqrt((1.88 Watts)^2+(1.8 Vars)^2) = 2.603 VA

That's my best guess at the answer, seems to simple to be right though.
You used the "Power Triangle" in concert with the Pythagorean theorem to solve! Great stuff! I did not see or thinkof that for whatever.  Reply With Quote

#### Tags for this Thread

apparentburden, current transformers, electrical calculations, electrical theory, neta exam questions, neta level 3, transformers Related Content 