Control panels typically use wires in the range of 0. 5 mm² to 16 mm², depending on the application: 0. 6 – 16 mm² – High-power devices and main supply lines. NFPA 79, a standard produced by National Fire Protection Association, outlines wiring regulations for industrial control panels that operate at 600 V or less. AWG (American wire gauge) is a measurement of diameter that clues buyers in. I'm designing my first full control cabinet and am stuck on a relatively simple decision: should I use 16 or 18 AWG MTW wire for the internal connections? I am not running anything more than a few meters with this wire, and very little total power (most devices externally powered). I need to buy. Choosing the right wire size for your control panel is one of the most important steps in ensuring safe and efficient electrical operations. The size of the control panel wire affects how well electricity flows, how much load the system can handle and how safe the entire setup is from overheating. In addition, main current wiring should not be less than 14 AWG and should be marked at the connection point with letters or numbers that match the circuit diagram provided in the control panel. For individual loads, UL 508A stipulates that the main current wiring for motors or heating systems. Calculate the minimum wire gauge (AWG) for your electrical circuit based on amperage, voltage, distance, and conductor material. Need Quick Wire Size Calculations? Use our professional wire.