Operating Instructions - Section 30 7/09 OM3050 Page 30-14 Line status signals Line status signals are lights that advise operators whether segments of trolley lines are energized and ready to accept haulage traffic. A different status sig- nal light is used for each section of the trolley line that is energized. Trolley disconnect Trucks operating on trolley assist may be rejected from a trolley assist line for several reasons. They include: 1. System current overload - The trolley system is capable of power output to a certain rating.
If too many trucks are using a section of line at one time, this rated power output may be exceeded and the section of line will automati- cally de-energize, rejecting the haulage units operating on that section of line. The lights are mounted to allow the driver to check the status of the line that the truck is approaching, so the pantograph can be lowered before that section of line is reached if the line is not able to accept haul- age trucks. Each ramp that is trolley equipped may have several different sections of energized trolley lines that make up the trolley line for the entire ramp. Each section of line that is energized will have a sep- arate line status signal. 2.
No throttle signal - If, at any time while on trolley assist, the operator releases the throttle pedal, the truck speed will slow down. When truck speed is below 8 kph (5 mph), the drive system will stop trolley operation, the pantographs will lower, and the truck will come to a stop. Then the anti-roll feature will hold the truck stationary. Move the directional control lever to the Park position immediately to hold the truck stationary.
Since it is important that a driver lower the panto- graph before the truck reaches a de-energized sec- tion of ramp, the drivers must constantly monitor the line status signals and lower the pantograph if the line status signals indicate that an approaching sec- tion of line is not ready to accept haulage trucks. If an operator approaches a line status signal that is indicating the line is not ready to accept haulage traf- fic, the driver will lower the pantograph before reach- ing that section of line.
After proceeding past the section of line and the next line status signal indi- cates the next section of line is ready to accept haul- age traffic, the operator will re-engage the trolley line as previously instructed and continue on trolley assist. 3. Electrical system malfunction - The truck is equipped with systems that monitor the status of the trucks trolley control system. If any abnor- mal condition is detected in the electrical sys- tem, the electric control system will lower the pantograph, and switch the truck back to the diesel mode.
If a truck is rejected while the operator has the throttle pedal fully depressed, the transition back to a diesel mode will be smooth and the operator will notice the truck speed decrease from trolley speed to diesel speed. The truck will not stop and the operator can proceed up the ramp. If the operator releases the throttle pedal, the truck will stop in either mode.