System Troubleshooting (Instability) - Doosan DP158LCF Operation & Maintenance Manual

• Over Speed : When the engine reaches the preset
overspeed, the lamp is on and relevant relay is acti-
vated and the power to the actuator is shut off.

System Troubleshooting (Instability)

1. Fast instability (Hunting)
1) When the position of switch D1 is ON, the differential
function is activated.
2. It provides fast transient response against engine
speed changes.
3. However, it may generate fast instability being sensi-
tive to external high frequency noise. In this case,
place the switch D1 to OFF position and readjust (2)
Gain and (3) Stability.
4. If instability should be still present, placing D2 to OFF
position may help stabilize the engine. Again, readjust
(2) Gain and (3) Stability for optimum control.
5. Slow instability (Hunting)
Slow instability can have many causes, most of which
are due to wrong setting against the engine charac-
teristics. Adjustment of (2) Gain and (3) Stability
usually cures most situations
6. If the troubleshooting above is not successful
1) Due to the controller at fault - Replace the controller
with new one.
2) Due to the external devices at fault (Actuator, fuel
injection device, turbine, etc) rectify the mechanical
devices.
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8. Fuel system