DrewE wrote:
Artum Snowbird wrote:
The most notorious reason for a high load is a loose connection. That loose connection causes a huge resistance in the circuit. What used to run fine under a ten amp fuse now wants 20 amps. The connection heats up and corrodes some more, burning the wires.
Take a good negative to the load. If that fixes it, look at the negative line back to the battery. Same with the positive side.
Many loads do not increase their current in response to a high resistance supply, but rather consume less current (lower voltage, less current, see Ohm's law). It's mainly things with some sort of active power supply that would behave otherwise. That's not to suggest that good connections are at all unimportant, of course; too much power dissipation at a poor connection could possibly start a fire, in the worst case, besides various lesser evils.
A poor connection at the breaker can cause it to trip prematurely since the breakers are thermally activated (at least these self-resetting ones generally are). The heat from the poor connection is conducted into the breaker. They also tend to get more sensitive with age, I gather.
I suspect the main problem here is that the converter is putting out more current than the old one, and the breaker is now undersized...and quite possibly also the wire that it's there to protect.
Very good explanation of a much misunderstood condition Drew.
In short, a loose connection does not increase current from the power supply. A loose connection lowers the current carrying capacity of that very connection and creates heat. If the connection is loose at a breaker, that heat causes the breaker to trip prematurely - not because there's suddenly more current.
