PLATE-THRUST 4S6417 - Caterpillar

Tachometer
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The tachometer is used in order to display the engine speed.The tachometer is a microprocessor based electronic instrument. The tachometer is designed in order to provide an accurate indication of the speed of the engine. The Tachometer measures the engine speed with a magnetic pickup that is connected to a ring gear on the flywheel. The digital LCD display is used in order to display the following information:
the numeric value
the units of rpm
the state of the output switches
a bar graphThe tachometer is equipped with four switched outputs in order to control the following relays:
"Crank terminate"
"Crank terminate time delay"
"Oil step"
"Overspeed"ReferenceRefer to Specifications, System Operations, Testing and Adjusting, RENR5851 for more information.Service Meter
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Service meterThe service meter indicates the total hours on the engine. The service meter is used in order to schedule engine service. The meter is driven off the contacts of the run relay. The meter operates after crank terminate speed is reached.Pressure Indicator (Starting Air)
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Pressure indicator for the starting airThe gauge indicates the air pressure that is available for the starting motor. The gauge receives a signal from the pressure sender for the starting air.The table shows the air pressures for the types of starting motors.
Table 1
Starting Air Pressures    
Type of Starting Motor     Minimum     Maximum    
Vane    
758 kPa (110 psi)    
1723 kPa (250 psi)    
Turbine    
621 kPa (90 psi)    
829 kPa (120 psi)    ReferenceRefer to System Operations, "Senders" for more information on the pressure sender.Pyrometer
Illustration 4 g00790657
PyrometerThe pyrometer is an electronic scanner for exhaust temperatures. The pyrometer monitors the temperature of each cylinder exhaust port. The pyrometer also monitors the exhaust temperature at the turbocharger inlet. If the engine has two turbochargers, the pyrometer monitors the exhaust temperature at both turbocharger inlets.The pyrometer has a microprocessor for processing the input signals. The microprocessor has non-volatile memory for storing programmable parameters and other data.The user interface is a keypad. The following functions are among the uses of the keypad:
Change the display of the temperatures to °C or °F.
Select automatic display or manual display for the scan.
Display a history of channels which have exceeded the setpoints.
Change the filter for the display in order to stabilize the readings for a signal that is fluctuating.
Program the temperature setpoints.
Lock the keypad in order to help prevent changing of the non-volatile memory.
Calibrate the scanner.The pyrometer monitors temperatures from 0 to 850 °C (32 to 1562 °F). An alarm is generated when the temperature from the turbocharger inlets exceeds the setpoint.ReferenceRefer to Service Manual, RENR4911, "Exhaust Temperature Scanner" for more information on the operation of the pyrometer.
Table 2
Identification of Pins for the Pyrometer for the EPG (1)    
Channel     Pin     Description     Channel     Pin     Description    
Thermocouple for Cylinder 1     1     Supply voltage