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Copyright 2017 Cummins Inc.
SYSTEM OVERVIEW
The PCC is a microprocessor-based control for
Cummins generator sets. It provides fuel control
and engine speed governing, main alternator volt-
age output regulation, and complete generator set
control and monitoring.
The operating software provides control of the gen-
erator set and its performance characteristics, and
displays performance information on a digital dis-
play panel. It accepts menu-driven control and set-
up input from the push button switches on the front
panel.
GENERATOR SET CONTROL FUNCTION
Figure 1-1 shows some of the control functions. A
more complete block diagram is provided in Section
3. A system schematic is provided in Section 8.
The PCC monitors frequency from both the mag-
netic pick-up (MPU) and the main stator inputs. The
control sends a low power pulse-width modulated
(PWM) signal to the governor output module, which
then sends an amplified signal to the engine fuel
control.
The external PT/CT module reduces alternator volt-
age to approximately 18 VAC, and produces a rep-
resentative AC voltage from CT output current. The
voltage regulation function sends a low power PWM
signal to the voltage regulator output module, which
then sends an amplified signal to the exciter stator.
Oil, coolant, and exhaust temperatures are sensed
by variable resistance element sensors. Oil pres-
sure is sensed by a capacitive element active sen-
sor.
Sensors
Governor
Output
Output
MPU
NS
PMG
Battery
BT1
Fuel
Control
Regulator
FIGURE 1-1. GENERATOR SET CONTROL FUNCTIONS
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