Elevator Mechanic Practice Exam

You need to work on a freight door retiring cam, you LOTO the main line but there is still power on the cam. What circuit is still hot?

1. Cab Light Circuit

2. Car Door Operator Circuit

3. Controller Circuit

4. Door Operator Disconnect

The correct answer is: Cab Light Circuit

The correct answer pertains to understanding the electrical systems involved in elevator mechanics. When a freight door retiring cam is in use and the main line has been locked out, if there is still power on the cam, it's likely due to a circuit supplying power specifically to its operation, which in this context, is the cab light circuit. The cab light circuit typically remains active even when other main power sources are disabled because it serves a purely illumination function that is often designed to be powered independently for safety and operational purposes. This would allow the area to remain lit for safe navigation and visibility during maintenance procedures. Other circuits like the car door operator circuit, controller circuit, or door operator disconnect typically deal directly with movement or operational controls of the elevator system. These circuits would generally be disabled when the main line is locked out to ensure that there is no unintentional movement or activation of the doors while maintenance is in progress. Thus, focusing on the cab light circuit being a potential exception provides clarity as to why there could still be power present despite the main line being deactivated.