Observe the gauges frequently while the engine is operating. Record the data from the gauges in a log regularly. Compare the data to the specifications for normal engine operation. Comparing the data over time will help to detect changes in engine performance.
Investigate any significant change in the gauge readings. Monitor the engine operation and take the appropriate action when discrepancies are found.
Operating the Engine and the Driven Equipment
Check the gauges and the driven equipment frequently while the engine is operating under a load. The engine can be operated for extended periods of time at full load.
Partial Load Operation and Hydrocarbon Release Procedures
Extended operation at low load may cause increased oil consumption and allow unburned fuel to pass through the exhaust system. Unburned fuel and oil passing through the SCR system can result in aftertreatment system damage if allowed to accumulate. The accumulation of fuel and oil on the catalyst is referred to as Hydrocarbon (HC) Loading.
To maintain engine efficiency, performance, and avoid possible SCR aftertreatment damage, the engine should be shut down rather than allowed to idle for an extended length of time. If the locomotive is equipped with an automatic shutdown feature, this feature can be utilized with the OEM factory settings to keep engine idle duration within safe limits.
The engine will continuously monitor HC catalyst levels and a warning will be triggered if the HC loading reaches a threshold.
If a warning occurs, a manually initiated mitigation procedure is recommended. This procedure slowly increases exhaust temperature and catalyst temperature while at high engine speeds and exhaust flow rates to release HC from the catalyst. During this procedure, the engine system control will continue to monitor the HC catalyst loading.
If the engine control reports excessive HC loading, execution of the mitigation procedure is recommended as soon as possible to minimize the required duration of the procedure and reduce the risk of system damage.
There are two levels of mitigation procedures depending on the severity of the issue. The two levels are Normal and Special load tests. Details on these procedures can be found in the "OEM Locomotive Operators Manual". Consult your locomotive OEM for more details.