Construction Machine

A plus-side main connection line () connects electrical equipment (), () to a plus terminal (A) of a battery (). A plus-side isolating switch () is provided in the plus-side main connection line () to connect or disconnect the electrical equipment (), () and or from the plus terminal (A) of the battery (). A plus-side auxiliary connection line () connects a urea SCR controller () to the plus terminal (A) of the battery () in a position upstream of the plus-side isolating switch (). A minus-side main connection line () connects a minus terminal (B) of the battery () to ground. A minus-side isolating switch () is provided in the minus-side main connection line () to connect or disconnect the minus terminal (B) of the battery () and or from ground.