TM 9-6115-730-24
0003
GENERATOR SET CONTROL (GSC) - Continued
GSC Outputs
The GSC outputs signals to the display, the ECM, Load Contactor K1, and the EMCP relay module. The GSC
display consists of an upper display, a lower display, and a column of indicators to the left of the upper and lower
displays. The upper display shows the average voltage, frequency, and total current the generator set is putting
out. By pressing the AC METER key on the touch pad, the upper display can display: line-to-line voltage,
generator frequency, and current for each phase; voltage line-to-line for all three phases; line current for all three
phases at once; or voltage line-neutral for all three phases at once. The upper display is also used to display any
fault codes identified by the GSC or by the ECM.
GSC Displays
The GSC lower display is capable of displaying one of the following:
Total Real Power (kW)
Real Power Phase A (kW)
Total reactive power (KVAR)
Real Power Phase B (kW)
Total apparent power (kVA)
Real Power Phase C (kW)
Percentage of rated power (%kW)
Power Factor Phase A
Power factor (average)
Power Factor Phase B
Total energy output (kW/h)
Power Factor Phase C
Total reactive energy output (kVARHr)
The lower display also has a series of arrows pointing downward to symbols printed below the display. These
arrows appear in order to indicate alarm conditions sensed by the GSC and/or ECM. The lower display also lights
up designations K1, K2, etc to indicate the condition of relays K1 through K8 in the relay module internal to the
GSC (Table 1). When a particular symbol appears, the associated relay is energized. This is strictly status and is
helpful when troubleshooting. An additional feature of the lower display is that of a synchroscope. When manually
synchronizing the generator output to another generator, the phase relationship between the generator and the
voltage on the load bus are shown graphically on the lower display. This allows the two systems to be brought in
sync before bringing the generator on line.
The column of indicators at the left side of the GSC indicate impending problems or what condition caused a
shutdown. The ECM resides on the engine and controls the operation of the engine, such as starting, stopping,
speed control through fuel control, ignition timing, and monitors various sensors on the engine. Problems
diagnosed by the ECM are sent via the CAT Data Link to the GSC and displayed on the GSC display with an E
suffix to identify them as engine diagnosed. The GSC sends a speed control signal and a governor on/off signal to
the ECM to control the speed of the engine, which determines the frequency of the output from the generator. The
GSC monitors various sensor outputs, plus the ECM sensors to enable or disable connecting the generator to the
load via Load Contactor K1. The GSC is also able to disconnect the generator from the load via Load Contactor
K1 in the event that the ECM or the GSC detects a failure that would keep the generator set from performing its
duty.
The GSC is a multi-purpose controller meant to be interfaced with a wide range of engine types and
configurations. The output from the GSC goes to a relay module inside the GSC and these relay outputs are
interconnected to the rest of the control system (refer to DC Power Distribution discussion for this interface). There
are also spare inputs and outputs described in the DC Power Distribution discussion. One of the purposes of the
GSC is to determine when the generator output is synchronized well enough with the voltage on the load bus in
order to connect the generator to the load. This can be done automatically or manually with the aid of the
synchroscope feature of the GSC.
0003-23