CT Burden Question
CT Burden Question
(OP)
I have encountered a situation with a resistance grounded system that has a 25 ampere neutral grounding resistor. There is a 25:5 CT in series with the resistor to measure ground fault current. The CT secondary is connected to three CO-11 relays that are connected in series using 300 feet of #12 AWG wire (total length). Each relay is set on the 0.5 ampere tap, and each relay is set at a different time dial setting. On one side, my gut tells me that there is too much burden connected to this CT, but on the other side, I only need to obtain 0.5 amperes for proper relay operation. Can someonse shed some light on this problem for me?
Regards,
Dave
Regards,
Dave






RE: CT Burden Question
To really analyze this, you will need the CT excitation curve, or at least the accuracy class of the CT. The relay burden data should be readily available.