3512B Petroleum Engines Caterpillar

Crankcase Pressure

Usage:

The ECM will automatically perform the following functions if high crankcase pressure occurs:

Warning
Derating
Shutdown

The default settings that are programmed at the factory are listed in Table 1.

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Table 1
Crankcase Pressure
Parameter	Default Setting
Warning setpoint	2 kPa (0.3 psi)
Warning delay	3 seconds
Derate setpoint	6 kPa (0.9 psi)
Derate delay	10 seconds
Maximum time of derating	480 seconds
Hysteresis	0.25 kPa (0.036 psi)
Security level	Required password
Maximum derating	15%
Shutdown setpoint	3.5 kPa (0.51 psi)
Shutdown delay	3 seconds

If the crankcase pressure is above 2 kPa (0.3 psi) for three seconds, a warning will occur. To deactivate the warning, the crankcase pressure must be below 1.75 kPa (0.254 psi).

If the crankcase pressure is above 6 kPa (0.9 psi) for 10 seconds, a derating will occur. The continuous schedule of the derating will reach 15 percent in 480 seconds.

When the crankcase pressure is less than 5.75 kPa (0.39 psi), the percent of the derating is decreased until full power is restored. However, if the crankcase pressure rises above the setpoint again, the derating resumes.

If the crankcase pressure is above 3.5 kPa (0.51 psi) for three seconds, a shutdown will occur.

Note: The default settings result in a shutdown that occurs before a derating. These settings were selected for the reason that high crankcase pressure can occur rapidly. The settings can be reprogrammed.