Komatsu WA200-8 Operation & Maintenance Manual page 179

OPERATION
HANDLE UREA SCR SYSTEM WARNING
• Exhaust gas temperature may increase during regeneration and remain very hot after the end of re-
generation.
Do not come near the exhaust pipe outlet nor the aftertreatment devices.
Do not put any combustibles near the outlet of the exhaust pipe nor the aftertreatment devices.
• Disable the regeneration system while the machine operates in an environment containing flamma-
ble materials.
The Urea SCR system device sprays DEF into the exhaust gas to convert toxic nitrogen oxides (NOx) from ex-
haust gas into harmless nitrogen and water. DEF decomposes and hydrolyzes to produce ammonia (NH3),
which selectively reacts with nitrogen oxides to convert nitrogen and water.
The Komatsu Urea SCR System continuously monitors machine operation conditions and gathers information
on defective operations such as malfunctions. The information is used for system diagnostics and also for In-
ducement, required on engine systems that use Urea SCR systems. Inducement is intended for the operators to
take prompt procedures to maintain and correct inappropriate behaviors of Urea SCR systems. Alerts in Induce-
ment of the Komatsu Urea SCR System progress step by step. It starts with visual indications on the machine
monitor with audible sounds to engine power deration to avoid dangerous conditions.
The Komatsu Urea System also monitors recurrences of defective operations of the system. Inducement is acti-
vated when another defective operation occurs less than 40 hours after the first defect is repaired.
When the purification function of the Komatsu Urea System is deteriorated from the machine operating condi-
tions, regeneration may activate.
NOTICE
• Do not put anything other than DEF into the DEF tank. Foreign materials in DEF, such as dried urea
when you disconnect the hose and change the filter, may cause a malfunction of the equipment.
• Do not paint the DEF injector or pump. Cover the pump and injector whenever you paint around
them.
• Use only DEF which complies with the quality standards. If you add any additive agents, water, etc.
to DEF, the equipment will not operate correctly, and will not comply with the exhaust gas regula-
tions. It may also cause a failure in the engine system. If you supply a solution other than DEF, con-
tact Komatsu distributor.
To prevent deterioration of the aftertreatment devices, the ex-
haust gas temperature rises automatically, which is regenera-
tion. During regeneration, the aftertreatment devices regenara-
tion display (1) comes on in the indicator lamp.
When the engine is idled for long periods of time, regeneration
will occur more frequently. This is not an error in regeneration.
When regeneration performance caution lamp (2) comes on,
stop the machine in a safe area and start manual stationary re-
generation.
Depending on the urgency, two steps to request manual sta-
tionary regeneration are started.
To stop the engine during regeneration, run the engine for more
than 5 minutes at low idle.
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WARNING
EXPLANATION OF COMPONENTS
3-115