Electrical Help Needed
As part of correcting a no brake issue on our trailer (small 23 foot), I decided to freshen up and rewire some components of the braking system. I will quickly admit, I knew/know very little when i...
Forum Discussion
enblethen wrote:
SAE have more circular mill copper wire!
SAE is LESS diameter than AWG.
SAE wire was developed for low voltage applications (60V or lower), typically for the automotive industry (Hint, SAE is an abbreviation for Society of Automotive Engineers).
I have some 12 SAE on hand.
Click For Full-Size Image.It measures 5/64" (1.98 mm) diameter
Compared to 12 AWG which measures 3/32" (2.38mm).
The last time I checked, 5/64" (1.98mm) is STILL smaller than 3/32" (2.38mm).
12 SAE will handle LESS current than 12 AWG unless you are fine with higher wire resistance, more voltage drop for the current and more heat generated through the wire.
Wire resistance is a real problem with 12V items.
Additionally, the 12 SAE I have is also marked with 60C temp and has a PVC jacket..
In the OPs case, they bought a 30A breaker for "8" wire, that is a safe bet. My TT used unmarked 8 ga wire, might have been SAE or could have been building wire or something in between.. But the RV manufacturer used a 40A breaker on the tongue and the converter side was fused at 40A..
So, I would say the OP can safely stick with the 30A breaker or possibly exchange it for a 40A breaker only if they run in to having the breaker cycle on/off all the time..
