>>1602999Those big units all have auto start/stop, so they normally shut down after five or ten minutes of inactivity. The crew can inhibit the engine stop for a couple of hours by pressing a button in the cab. If you know another crew is going to be coming along in a couple of hours or less it's normal to leave the lead unit running to keep the cab warm. The AESS will also restart the engine when it gets really cold just to warm it up.
Older units were designed when fuel costs weren't a consideration and were supposed to idle all the time, although some have been given AESS kits to shut down like the road units will. If they don't have such a kit, starting them on a cold day is difficult and should be avoided at all practical cost.
