EPC-250 IOI 6-18 All rights reserved © ALTRONIC, LLC 2018
20
10.15
Reset RPM
When the engine RPM is greater than the Reset RPM value, the controller will
enter auto mode.
11.0 TIMING RETARD
Ignition timing is a 4–20mA output signal and is a function typically of one or
more of the following parameters:
Timing Retard vs. Fuel Manifold pressure
Timing Retard vs. Exhaust Temperature
Timing Retard vs. Air Manifold Temperature
Timing Retard vs. Speed
Timing Retard vs. Pilot Manifold Pressure
Timing Retard vs. Air Manifold Pressure
The operating values for the functions above are calculated separately accord-
ing to user-entered curves, and the Offset is implemented by the EPC-250
Controller.
Under certain conditions, there can be interaction between the Air/Fuel Ratio
and the Timing Retard function. If sufficient air manifold pressure cannot be
achieved—even with the bypass valve fully closed—the ignition timing can
be retarded to increase the exhaust temperature. This provides more energy
to the turbocharger so that the air manifold pressure can be increased and
brought into the desired range. This is the Air/Fuel Ratio Override condition.
There is also a Start Override condition where the bypass valve is kept fully
closed and ignition timing is set to a specific value.
