Probable Effect Concentration Quotients (PECQS) Practice Test

The correct response is that low-impedance shunt circuits are not permitted on the supply side of the service disconnecting means because these circuits can create safety hazards. Low-impedance shunt circuits facilitate the flow of current with minimal resistance, which can lead to unintended current paths or overloads. This presents a significant risk, as shunt circuits might bypass the protective devices that are designed to interrupt the flow of electricity during fault conditions. In contrast, high-resistance circuits, service transformers, and connection terminals have specific roles and characteristics that make them acceptable on the supply side. High-resistance circuits typically limit current flow, reducing the likelihood of overloads. Service transformers are necessary to step down voltage for safe distribution in residential or commercial applications, while connection terminals serve as the designated points for making secure electrical connections, all without compromising system safety.