I am trying to calculate and measure the electrical load for a property that consist of several buildings, to find out if our generator can adequately handle the load. In the main entrance there are CT's on each phase going to a box with a circuit board that contains the burden resistors, small transformers, rectifiers and a DC output.
The only info on this board says that has a 0-10vdc output. The DC output disappears down a conduit that nobody seems to know the end of. So I'd like to know if I can use this DC voltage to conveniently measure the real time current draw.
Here's the numbers:
CT ratio 1600/5, or 320/1
DC voltage output about 3.0v
Burden resistor 0.2 Ohms
I measured the voltage drop across the burden resistors and it was about 0.05v on each phase, which translates to 0.25A, or about 80A per phase on the mains supply.
I'm not sure where to go to next. My questions:
Can I calculate a factor from these numbers that can convert the DC voltage to an AC current reading? and is the relationship linear?
How does the circuit combine the 3 phase currents into one DC voltage, is it added, or averaged, or something else?
I was thinking that the 10vDC output would represent 5A output from the CT's, but the numbers don't seem to fit
Thanks for your expertise
The only info on this board says that has a 0-10vdc output. The DC output disappears down a conduit that nobody seems to know the end of. So I'd like to know if I can use this DC voltage to conveniently measure the real time current draw.
Here's the numbers:
CT ratio 1600/5, or 320/1
DC voltage output about 3.0v
Burden resistor 0.2 Ohms
I measured the voltage drop across the burden resistors and it was about 0.05v on each phase, which translates to 0.25A, or about 80A per phase on the mains supply.
I'm not sure where to go to next. My questions:
Can I calculate a factor from these numbers that can convert the DC voltage to an AC current reading? and is the relationship linear?
How does the circuit combine the 3 phase currents into one DC voltage, is it added, or averaged, or something else?
I was thinking that the 10vDC output would represent 5A output from the CT's, but the numbers don't seem to fit
Thanks for your expertise