Operational Modes - Detroit Diesel Series 60 EGR Technician Manual

SERIES 60 EGR TECHNICIAN'S MANUAL
3

OPERATIONAL MODES

New terminology has been introduced as a result of the Series 60 EGR engine.
Boost Mode — Boost Mode is when the engine is generating power with NO EGR flowing. The
EGR valve position is closed and the vanes in the turbocharger adjust to achieve a desired boost
level. Boost levels are similiar to 'pre-EGR' engines.
Transition from Boost to EGR Mode — Transition from Boost to EGR Mode is when the
engine is generating power using boost pressure and DDEC requests the EGR to begin flow.
EGR Mode — EGR Mode occurs when DDEC is flowing EGR at a desired rate to maintain
proper engine operation. The EGR valve position is open and vanes in the turbocharger adjust
to achieve the desired EGR rate. Typically boost levels are higher under this operating mode
when compared to 'pre-EGR' engines.
EGR Control Mode — EGR Control Mode occurs when the DDEC engine sensors are
performing normally and all engine parameters are within calibration limits as determined by the
sensor readings. These readings enable DDEC to accurately control exhaust gas flow.
Transition from EGR to Boost — Transition from EGR to Boost Mode occurs when the engine
is generating power while flowing EGR and DDEC requests to close the EGR valve and generate
power based upon boost pressure.
Braking Mode — Braking Mode occurs when the engine is absorbing energy (power) through an
internal engine-braking device. The power for the engine brake is accomplished by activating the
desired number of cylinders and adjusting the vanes in the turbocharger to achieve the desired
boost level. The EGR valve position is closed during brake mode.
Altitude — The engine will transition between EGR and boost mode at an altitude of 6500 ft.
Altitude is determined by the Barometric Pressure Sensor located on the engine. See Figure 2-3.
Condensation Protection— In very cold ambient (i.e. < 30F) conditions the engine will operate
in a "condensation protection" mode. EGR is disabled during this mode requiring a slower turbo
speed. The engine will sound "different". During this mode of operation the operator will notice a
lower "boost" reading compared to when EGR is active, however there is NO reduction of power.
3-1
All information subject to change without notice. (Rev. June 2005)
7SE60 0506 Copyright © 2005 DETROIT DIESEL CORPORATION