Regeneration
Regeneration is the removal of soot from the Diesel Particulate Filter (DPF). There are two different types of DPF that can be installed The through flow DPF and the wall flow DPF. Engines with a power output of 56kW and above will have the wall flow DPF installed. Engines with a power output below 56kW have the option to use both types of DPF.
In table 1 titled Indicator Operation the operator will find information on the regeneration indicators. The table informs the operator why an indicator is illuminated and what action should be taken.
Through Flow DPF
The through flow DPF uses passive regeneration in order to remove the soot from the DPF. Passive regeneration is a chemical reaction within the system. Normal operation of the engine creates enough heat for a chemical reaction in order to regenerate the DPF. The regeneration occurs automatically during normal engine operation.
This system uses an amount of active regeneration in order to ensure that soot cannot exit the DPF. The through flow DPF will not require manual cleaning.
For a typical view of the through flow DPF, refer to this Operation and Maintenance Manual, "Sensors and Electrical Components (Aftertreatment)"
Wall Flow DPF
The wall flow DPF uses passive regeneration and active regeneration in order to remove the soot from the DPF. The ash is trapped within the DPF and must be removed by a manual cleaning process Refer to Operation and Maintenance Manual , "Diesel Particulate Filter- Clean".
For a typical view of the wall flow DPF, refer to this Operation and Maintenance Manual, "Sensors and Electrical Components (Aftertreatment)"
Regeneration Indicators
Five indicators can be affected by the DPF regeneration. these indicators are, Regeneration Active, DPF, Disable Regeneration, Amber, or Yellow Warning Indicator and Red Stop Indicator.
| Regeneration Active - This indicator will illuminate during active regeneration. The indicator shows that elevated exhaust temperatures are possible. The indicator will be turned off when regeneration is complete. |
| DPF - This indicator provides a general indication of the soot load. The indicator is off when the soot load is normal. |
| Disable Regeneration - This indicator is illuminated whenever the disable switch is activated. |
Modes of Regeneration
- Automatic regeneration
- Forced regeneration
Automatic regeneration - Automatic regeneration will occur when the level of soot reaches the trigger point that is set in the ECM. The engine can operate normally during an automatic regeneration.
Manual - A manual regeneration is initiated by pressing the regeneration switch. A forced regeneration can only be performed after the soot load has illuminated the DPF indicator . A forced regeneration will only be required if the automatic regeneration has not been completed. This situation can be due to either the disable switch being operated or the duty cycle of the engine.
Note: In some applications the engine safety interlocks will need to be in place before a forced regeneration can occur.
Regeneration Switch
Note: The regeneration switch is a three position switch. Some OEMs may use other means of activating a forced regeneration such as touch screen interfaces.
| Force Regeneration - Press in the top of the switch for 2 seconds in order to begin regeneration. |
| Disable Regeneration - Press in the bottom of the switch for 2 seconds in order to disable regeneration. Press again in order to return to automatic mode. |
Note: Turning the keyswitch to the OFF position will remove the disable regeneration input and return the engine to automatic mode of regeneration.
Note: The MIDDLE position of the regeneration switch is the default position for automatic regeneration.
Note: You may return to normal operation at any point during a regeneration.
Regeneration System Warning Indicators
Some applications may also have an audible warning installed.
| Indicator Operation | |||||
| During passive regeneration no indicator will be illuminated | |||||
| Aftertreatment Indicator | Aftertreatment Indicator State | Warning Indicator | Warning Indicator State | Description | Action Required |
| Regeneration Active indicator | On Solid | None | None | Regeneration is activated. The indicator will stay illuminated during regeneration. | None |
| - | |||||
| DPF Indicator | On Solid | None | None | The indicator provides a general indication of the soot load. The indicator is off when the soot load is normal. | A regeneration is required. In automatic mode the ECM will decide when to allow the active regeneration. If the DPF indicator stays illuminated allow a manual regeneration without interruption. An uninterrupted active regeneration will reset the DPF indicator. |
| - | |||||
| DPF Indicator | On Solid | Amber indicator | Flashing | The indicator indicates that the soot load has increased. The engine will derate. |
A manual regeneration is required. Perform a manual regeneration, or a service regeneration will be required. |
| - | |||||
| DPF Indicator | On Solid | Amber indicator | Flashing | The flashing warning indicator and red stop indicator indicates that the engine has continued to be operated while a regeneration is required. The engine will be derated and the engine should be shut down immediately. |
Once the engine enters into shutdown mode, you must contact your Cat dealer. Your dealer will need to perform a service level regeneration. The DFP may need to be replaced. |
| - | - | Red indicator (STOP) | On Solid | ||
Note: Amber or yellow warning indicator can be used as a diagnostic lamp. For more information refer to this Operation and Maintenance Manual, "Diagnostic Lamp".
Regeneration Operation
Regeneration will require the following conditions:
Automatic Regeneration
In order for an automatic regeneration to take place the engine must be at operating temperature.
Turning the keyswitch to the OFF position during a regeneration will stop the regeneration. An interrupted regeneration will not remove the soot from the DPF and will waste fuel.
Wall Flow DPF Only
The engine Revs Per Minute (RPM) must be above 1200 RPM for the regeneration to start. Normal operation can continue. During an automatic regeneration the minimum idle speed will be controlled to 950 RPM.
Manual Regeneration
The DPF indicator must be illuminated. Where applicable, safety interlock for your application must be engaged before a manual regeneration can occur, refer to your OEM for more information. No throttle inputs are required, the ECM will control the engine RPM. Press the force regeneration switch for 2 seconds. Do not operate the application during the manual regeneration.
Service Regeneration
The electronic service tool will be required in order to perform a force regeneration. Contact your Cat dealer.