I set my multimeter like this.
Plug the black lead to the short tab of NEMA5-15 receptacle first and the red lead to the long tab.
The moment I put the red lead in, there was a big spark. The circuit breaker was blown. And both of my lead is burned pretty bad like this
What did I do wrong? Can someone explain it to me? Is it because I plugged the black lead to hot line of the NEMA5-15?
Before doing like what I described, I had done another run with the lead mistakenly plugged in the meter like this
Everything seemed fine to me. And the meter displayed ~3.5A Then I realized I plugged the lead in wrong post so I swap the red lead and accident happened.
Can someone please explain this phenomenon to me?