No, only the Low Level Switching and CANbus versions draw current when idle.  The typical current draw is 30-40mA on 24 Vdc units and 15-20mA on 12 Vdc units when not in 'sleep mode.'  We developed the 'sleep mode' to minimize this current draw. Sleep mode will draw less than 1ma at 12v and less than 2ma at 24v.