100A DC Ammeter Shunt Resistor

Direct current instrument shunts are used to extend the range of ammeters whenever the current to be measured is too large to be passed through the instrument—usually currents over 50 amperes. The shunt, therefore, is a diverter which is used to “shunt” the majority of the current around the indicating instrument. Essentially the shunt is a specially-designed resistor which delivers a millivolt output (to a millivolt meter or instrument) in proportion to the current flowing through the resistor.