Short_Shot
Solar Addict
- Joined
- Jul 13, 2021
- Messages
- 1,823
Sand the oxide off, torque it down tight.1) For a short distance, wire cross section (or AWG) doesn't matter for ampacity, because heat gets to escape in 3 directions including lengthwise.
2) Actual cross section carrying current in a pressure contact is nothing near the apparent area. Maybe 1%, high spots that make contact.
I think what matters is a particular clamping force (for a given current), and avoiding having the contact surfaces move relative to each other (e.g. cable causing terminal to rotate.) If the welded on lugs tolerate twice the torque, that is what I would prefer. Just need to deal with cable connections - either secured against motion, or cable so limber it doesn't apply force to terminal.
But your math comparing contact area to 2/0 does mean there shouldn't be concern area is too small.
You could lap them too if you're REALLY motivated but that's definitely overkill.