General Information - MQ Power DCA25SSIU4F Operation Manual

GENERATOR
This generator (Figure 3) 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.
OPERATING PANEL
The "Operating Panel" is provided with the following:
„ ECU Controller
„ Gauge Unit Assembly
• Oil Pressure Gauge
• Water Temperature Gauge
• Charging Voltmeter
• Fuel Gauge
• Tachometer
„ Panel Light/Panel Light Switch
„ Pre Heat Lamp
„ Warning lamp (Diagnostic)
„ Hour Meter
„ Engine Speed Switch
„ Auto Start/Stop Switch
„ Fuel Leak Detected Alarm Lamp
CONTROL PANEL
The "Control Panel" is provided with the following:
„ Frequency Meter (Hz)
„ AC Ammeter (Amps)
„ AC Voltmeter (Volts)
„ Ammeter Change-Over Switch
„ Voltmeter Change-Over Switch
„ Voltage Regulator
„ 3-Pole, 60 amp Main Circuit Breaker
„ "Control Box" (located behind Control Panel)
• Automatic Voltage Regulator
• Current Transformer
• Over-Current Relay
• Starter Relay
OUTPUT TERMINAL PANEL
The "Output Terminal Panel" is provided with the following:
„ Two 120/240V output receptacles (CS-6369), 50A
„ Two auxiliary circuit breakers, 50A
„ Two 120V output receptacles (GFCI), 20A
„ Two GFCI circuit breakers, 20A
„ Five output terminal lugs (3Ø power)
„ Battery Charger (Option)
„ Jacket Water Heater (Option)
„ Low Coolant Switch (Option)
PAGE 14 — DCA25SSIU4F 60 HZ GENERATOR • OPERATION MANUAL — REV. #4 (01/17/18)

GENERAL INFORMATION

OPEN DELTA EXCITATION SYSTEM
Each generator is equipped with the state of the art "Open-
Delta" 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 rectified 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 configuration 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 open-delta design provides virtually unlimited excitation
current, offering maximum motor starting capabilities. The
excitation does not have a "fixed ceiling" and responds
according the demands of the required load.
ENGINE
This generator is powered by a 4 cylinder, 4-cycle water
cooled, direct injection, turbocharged, EGR Isuzu
diesel engine. This engine is designed to meet every
performance requirement for the generator. Reference
Table 2 for engine specifications.
In keeping with MQ Power's policy of constantly improving
its products, the specifications 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.
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