RING G.-PISTON 4F9862 - Caterpillar

Illustration 1 g00274430
Illustration 2 g00620114
"MAGNET ON" (1) - If this indicator comes on, the magnet is energized."VOLTS FAULT" (2) - If this indicator comes on, the voltage is too high or the voltage is too low in order to properly operate the magnet. One or more of the following items could remedy the problem:
Check the electrical connections.
Inspect the generator field resistor.
Check that the generator is operating at the correct speed (1750 RPM).
Check the generator."OVER 75% D.C." (Duty Cycle) (3) - If this indicator comes on, the magnet is being operated more than 75 percent of the time."GEN HOT" (4) - If this indicator comes on, the generator is overheating. One or more of the following items could be the reason that the generator is overheating:
The magnet is too large.
There is a short or a ground in the system.
The duty cycle is too high.
The voltage is too high.
There is insufficient airflow through the generator.
The generator is faulty."+ GND FAULT" (5) - If this indicator comes on, the resistance to ground in the positive line has dropped below 50,000 ohms."- GND FAULT" (6) - If this indicator comes on, the resistance to ground in the negative line has dropped below 50,000 ohms."DROP TIME" (7) - The drop time is controlled by a control dial and a range switch. The settings of both controls will vary depending on the size of the magnet. To achieve the best drop time for a given magnet, you should use the procedure below. Use the following procedure to set the "DROP TIME".
Determine the size of magnet that is installed on the machine. Locate the settings for the magnet in Table 1.
Set control dial (7) to the lower value that is given in Table 1. Set the range switch to the position that is shown in Table 1. The range switch is located on the lower right exterior of the "PLC" enclosure.
Table 1
Initial Settings    
Size of Magnet (kW)    Magnet Cold Rating (amperes)    Position of Control Dial    Position of Range Switch    
0 to 7     0 to 30     1 to 4     OFF    
7 to 10     30 to 45     1 to 6     OFF    
11 to 15     45 to 70     1 to 7     OFF    
16 to 25     70 to 110     2 to 8     OFF    
1 to 6 ON    
26 to 45     110 to 220     3 to 8     ON    
Lift the load and drop the load at consecutively higher settings until a clean drop is achieved.
Record the settings and the size of the magnet that is being used. When the same magnet is installed, set the control dial and the range switch to the recorded settings.Note: The initial settings are only suggestions. The actual settings may vary depending on the manufacturer of the magnet. The type of magnet and the material type and consistency will affect the setting. The dial setting will usually be higher for larger