Standard houshold 20 ampere AC receptacle to feed 12Vdc 200 ampere battery jumper /charger but how?

[LarryFine]

Ok so the primary never sees more than 20 I amperes because of the primary secondary ratio

Unless the secondary exceeds 200a. That's how primary OCP sometimes protects the secondary. too.

 

[LarryFine]

Because breakers are 100% current rated devices.

Right. Only their internal impedance "translates" current into power/heat.

 

[jim dungar]

Right. Only their internal impedance "translates" current into power/heat.

Yep. But voltage is not considered by the trip element. Breakers follow the same trip curve regardless if the applied voltage is 48V or 240V.

 

[LarryFine]

Yep. But voltage is not considered by the trip element. Breakers follow the same trip curve regardless if the applied voltage is 48V or 240V.

Exactamundo. It's regular voltage drop, which is only dependent on current and impedance.