• Press “PROG” to come in CT Primary surface, the default is "500---5" which means the ratio is 500:5A. The secondary current is 5A Max which can not be changed.
• Press "+" to increase the CT Primary,press "-" to decrease the CT Primary.
• After edition, press "PROG" to save the parameters and exit from surface. The system will automatically exit within 6 seconds if no other buttons are pressed but the edited parameters can not be saved.

2, when the parameters' range is 100-200, the distance of adjustment is 10.