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PAGE 16 — DCA800SSK2 60 HZ GENERATOR • OPERATION AND PARTS MANUAL — REV. #0 (09/03/09) 
GENERATOR
The MQ Power Model DCA800SSK2 is a 640 kW generator 
(Figure 3) that is designed as a high quality portable 
(requires a trailer for transport) power source for telecom 
sites, lighting facilities, power tools, submersible pumps 
and other industrial and construction machinery.
ENGINE OPERATING PANEL
The “Engine Operating Panel” is provided with the following:
Tachometer
 
Emergency Stop Switch
 
Water Temperature Gauge
 
Oil Pressure Gauge
 
Charging Ammeter Gauge
 
Fuel Level Gauge
 
Pilot Lamp
 
PreHeat Lamp
 
Engine Speed Switch
 
Battery Switch
 
Engine Alarm Lamps (6)
 
GENERATOR CONTROL PANEL
The “Generator Control Panel” is provided with the following:
Frequency Meter (Hz)
 
AC Ammeter (Amps)
 
AC Voltmeter (Volts)
 
Ammeter ChangeOver Switch
 
Voltmeter ChangeOver Switch
 
Voltage Regulator
 
Panel Light/Panel Light Switch
 
3Pole, 2500 amp Main Circuit Breaker
 
“Control Box” (located behind the Gen. Control Panel)
 
Automatic Voltage Regulator
• 
Current Transformer
• 
OverCurrent Relay
• 
Voltage Rectifi er
• 
Starter Relay
• 
Engine Controller (Computer Controlled)
• 
Voltage ChangeOver Board
• 
OUTPUT TERMINAL PANEL
The “Output Terminal Panel” is provided with the following:
Three 240/139V output receptacles (CS6369), 50A
 
Three auxiliary circuit breakers, 50A
 
Eight output terminal lugs (3Ø power)
 
Battery Charger (Optional)
 
Water Heater (Optional)
 
OPEN DELTA EXCITATION SYSTEM
The DCA800SSK2 generator is equipped with the state 
of the art “OpenDelta” excitation system. The open delta 
system consist of an electrically independent winding wound 
among stationary windings of the AC output section.
There are four connections of the open delta A, B, C and 
D. During steady state loads, the power from the voltage 
regulator is supplied from the parallel connections of A to 
B, A to D, and C to D. These three phases of the voltage 
input to the voltage regulator are then rectifi ed and are the 
excitation current for the exciter section. 
When a heavy load, such as a motor starting or a short 
circuit occurs, the automatic voltage regulator (AVR) 
switches the confi guration of the open delta to the series 
connection of B to C. This has the effect of adding the 
voltages of each phase to provide higher excitation to the 
exciter section and thus better voltage response during the 
application of heavy loads. 
The connections of the AVR to the AC output windings are 
for sensing only. No power is required from these windings.
The opendelta design provides virtually unlimited excitation 
current, offering maximum motor starting capabilities. The 
excitation does not have a “fi xed ceiling” and responds 
according the demands of the required load.
ENGINE
The  DCA800SSK2 is powered by a 6 cylinder, water 
cooled,  direct injection, turbocharged airtoair KOMATSU 
SAA6D170E3 Diesel Engine. This engine is designed to 
meet every performance requirement for the generator. 
Reference Table 2 for engine specifi cations. 
In keeping with MQ Power’s policy of constantly improving 
its products, the specifi cations quoted herein are subject 
to change without prior notice.
ELECTRIC GOVERNOR SYSTEM
The electric governor system controls the RPMs of the engine.  
When the engine demand increases or decreases, the 
governor system regulates the frequency variation to ±.25%. 
EXTENSION CABLES
When electric power is to be provided to various tools or 
loads at some distance from the generator, extension cords 
are normally used. Cables should be sized to allow for 
distance in length and amperage so that the voltage drop 
between the generator and point of use (load) is held  to 
a minimum. Use the cable selection chart (Table 6) as a 
guide for selecting proper extension cable size.
GENERAL INFORMATION