The answer comes from the NEC section 250. 162, referring to the grounding of two-wire DC systems, which includes the 5V and 24V outputs, depending on your case. Some of these rules differ from those intended explicitly for alternating-current (AC) systems. Although most electrical energy produced commercially is generated, transmitted, and. Most DC power supplies installed within control cabinets output the common 24 volts. Computer power supplies (including PLC power supply units, or PSUs) usually output 5V and +/- 12V, all at a constant, direct current polarity. When examining the output wires, they only contain a + and a – terminal and. This document describes the requirements and power and safety ground cable wiring instructions for systems equipped with a – (48–60) V DC power supply. This installation should only be done by a certified service technician. Similarly, a bad quality of.
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