I have a question about where a round trip distance for a device starts/stops. Is the source for a device the fuse panel (where the positive starts and negative return for that device) or the breaker that feeds the fuse panel?
In this scenario (see attached image), do I use 12 ga from the fuse panel to the dash socket or do I continue with the same gauge as the feed to the fuse panel?
In other words, is the round trip for the dash socket from fuse panel and back or from breaker and back?
A 20 amp breaker on main DC panel protects the 8 ga wire feeding the fuse panel
One way distance to main DC panel/breaker: 15 feet (8 ga)
One way distance from fuse panel to dash socket: 5 feet (12 ga)
Distance from fuse panel to light fixture: 7 feet (< 18 ga, but increase to 16 ga)
Dash Socket 12V DC with Watertight Cap, Blue Sea # 1011
6.75" LED Cabin
Dash Socket: 15 Amp max
Light: 0.23 Amp max
ATC Fuses in the fuse panel:
Dash socket: 20 Amp
Light: 1 Amp
Calculated wire gauge based on amps and distance:
Breaker to Fuse panel: 8 ga
Fuse panel to light: 16 ga
Fuse panel to dash socket: 12 ga
* If dash socket round trip is from breaker, the 8 ga goes up to 6 ga