GEAR ASSEM. (81 Teeth) 7S8501 - Caterpillar

Retrofit SCR Aftertreatment Operation
Software Version
Illustration 1 g03655343
The Retrofit SCR Closed-loop Controller, once properly commissioned, is designed to operate without operator intervention. The system uses all sensor inputs to determine start-up, shut down, and the precise amount of DEF to deliver to the injection system. The controller software measures operating conditions and adjusts the amount of DEF injection to achieve the desired reductions.The "Operation " page web address is http://169.254.02/caterpillar/web/operation.htm. The "Operation " page can be viewed on the touch screen and the user can monitor operating parameters. The following parameters can be viewed:
System Name (location and site specific)
Cabinet Serial Number
SCR System Serial Number
Engine Serial Number
Status (current state of the SCR system)
Current mode
Dosing hours
Controller Temperature
Boost Pressure
Boost Temperature
Exhaust backpressure
Exhaust alarm limit
Exhaust temperature
Heater temperature
Exhaust inlet temperature
Exhaust outlet temperature
Pump output of DPF
Cumulative DEF
Heater Output (if equipped)
Software version
Status windowModes of Operation
Standby - The green LED lamp is the only lamp on. No air or DEF is flowing and the system has purged. Standby is the default mode. The system will return to Standby anytime an operational condition is not met. Refer to the Status section for more information.Sensor Check - The SCR controller checks air pressure status and initiates NOx sensor warm-up, which takes 3 minutes.Tube Fill - "Tube Fill" is used any time the system switches from standby to normal operation. This mode fills the DEF line until NOx reduction begins. The blue LED will flash once DEF starts to flow.Run - Once "Tube Fill" is completed, "Run" mode will begin. "Run" mode is indicated by a solid blue LED. "Run" mode is the normal operating condition of the system. DEF is being dosed to the injector assembly according to the amount of NOx in the exhaust, boost pressure sensed, and the dosing map flow rate. The pump flow rate will vary accordingly to the engine load.Dry Out - A presence of DEF has been sensed at system startup. A greater than 15 percent emissions reduction is sensed before dosing has begun. Dosing will not begin until the residual DEF can be burned from the reactor. This process enhances the performance of the system once dosing begins.Manual Purge - A manual purge switch is provided on the DIN rail to allow the user to exit normal operation. Once the switch is triggered, the red LED will begin to flash and the system will enter a purge mode (flashing blue LED). Once the purge is complete, the system will enter startup mode and continue to run. If the conditions are not met when the switch is returned, the system will remain in standby until the conditions are met. The flashing red LED will turn off.Slip - Excess DEF has been sensed within the SCR system. Dosing has been temporarily suspended until system dry out is achieved.Rate Reduction Mode (RRM) - Successive slip events have triggered a Rate Reduction Mode and the system is operating at a lower reduction target than specified at system set-up.Note: Ensure that the switch is returned to the Off position