WASHER-THRUST 7N7539 - Caterpillar

System Operation Description:
Illustration 1 g00481725
Block Diagram Of The Voltage Display In the EMCP II
Table 1
Selection of AC Voltage Range    
GSC P20 Setpoint    Trans-former    Input Voltage    GSC Internal Multiplier    Jumper    
700     None     0 - 700     5     Required    
150     None     0 - 150     1     None    
300     2:1     0 - 150     2     None    
500     3.33:1     0 - 150     3.33     None    
600     4:1     0 - 150     4     None    
750     5:1     0 - 150     5     None    
3000     20:1     0 - 150     20     None    
4500     30:1     0 - 150     30     None    
5250     35:1     0 - 150     35     None    
9000     60:1     0 - 150     60     None    
15000     100:1     0 - 150     100     None    
18000     120:1     0 - 150     120     None    
30000     200:1     0 - 150     200     None    Note: For related information, see Testing And Adjusting, "AC Voltage Range - Adjust".The P20 setpoint determines the proper AC voltage range and the internal multipliers that are used by the GSC for calculating AC voltage. If the external potential transformers are present, the GSC uses the internal multipliers to compensate for the ratio of turns of the external potential transformers. This must take place in order to ensure accurate calculations by the GSC for AC voltage .A jumper block is located in the relay module. The jumper block connects a circuit which will divide the AC voltage by five. The circuit reduces the AC voltage to an acceptable level for the GSC when P20 is 700. When setpoint P20 is 700, a multiplier of five is needed to compensate for the presence of the circuit even though no external potential transformer is present.Note: The jumper block should NOT be installed when P20 is NOT programmed to a value of 700. This will prevent voltage readings that are calculated incorrectly by the GSC. The other values (150 through 30000) are used with an external potential transformer. These values result in input voltages from 0 to 150 ACV at the AC Transformer Box (ATB). No further reduction of the input voltage is required.
When the engine-generator, or any source to which the engine-generator is synchronized to, is operating, voltages up to 600V are present in the control panel.Do not short these terminal with line voltage to ground with any part of the body or any conductive material. Loss of life or injury could result from electrical shock or injury from molten metal.
Test Step 1. CHECK THE DISPLAY OF THE GSC FOR VOLTAGE READINGS
Start the genset.
Check the voltage readings on the display of the GSC.Expected Result:The voltage readings on the GSC should be accurate.Results:
OK - The voltage readings on the GSC are