What is the data wire gauge for a mid cable?

• A. 22 awg
• B. 18 awg
• C. 20 awg
• D. 16 awg

Answer: (C)

On a NMEA 2000 network, the mid cable carries the CAN data as a shielded two-conductor pair. The conductor size is chosen to balance signal integrity, impedance, and ease of installation. Twenty-gauge wire provides a practical blend: it keeps the differential CAN signal impedance and voltage drop within acceptable limits over typical mid-cable lengths, while remaining flexible and cost‑effective for a data-only path. Thinner wire would raise resistance and worsen signal integrity, especially on longer runs, while thicker wire isn’t needed for the low current of CAN data and would add needless bulk and cost. So twenty-gauge is the standard suitable size for the mid-cable data wires.