Integral capacitive divider bus bar voltage measuring apparatus and

Abstract

The first capacitor of a capacitive divider adapted for measuring the voltage on a bus bar utilizes the bus bar as one plate, the normal insulation provided on the bus bar as the dielectric and a first conductive layer applied over the insulation as the second plate. While a separate capacitor can be used for the second capacitor of the capacitive divider, preferably the first conductive layer serves as a common plate for both capacitors, with a second insulation layer applied over the first conductive layer forming the dielectric of the second capacitor, and a second conductive layer applied over the second insulation layer serving as the second plate which is grounded. The voltage on the common plate formed by the first conductive layer is applied to a voltmeter to provide a voltage reading proportional to the voltage on the bus bar. A particularly simple, compact combined voltage and current sensor is provided by aligning a mutual inductor current sensor with the integral capacitive divider so that the outer conductive layer of the capacitive divider serves a voltage shield for the current sensor.