When the current surpasses about 30A, it trips. By pressing the button, you can latch it. When the green LED is on, it is latched. When the red one is on, it is tripped. I added the potentiometer to account for differences in the Rds (resistance when on) of the MOSFET because one might have a different Rds than another. This particular one being simulated has an Rds of 14.3mΩ. The potentiometer can be adjusted to account for MOSFET Rds ranging from high as 30mΩ to as low as 0Ω.
Edit: Apparently there may be some confusion as to which resistor is load and which resistor is used to sense the current. The 2ohm resistor with the blue oscilloscope reading is the load. The 33mOhm resistor combined with the MOSFET Rds is the resistance used to measure the current.
