Abstract: A powered circuit, such as a sensor circuit that is configured to be affixed to a power distribution cable in a grain bin temperature and humidity sensing system, is subject to electrostatic discharge (ESD) events. The circuit described herein provides a discharge path that advantageously diverts charge in an ESD event to the power bus ground while protecting internal components in the powered circuit from ESD damage. A probe circuit has an ESD probe that is located proximate to an aperture in a circuit housing cover. The probe circuit is connected to the input power bus ground. An isolation circuit coupled to the input power bus isolates circuit board power and ground from the power and ground supplied by the power bus. The isolation circuit includes a resistor serving as a component of a low-impedance power loop. A limiting component limits the voltage experienced by the powered circuit.