Multiquip DCA-25SSIU2 Portable Generator User Manual


 
PAGE 18 — DCA-25SSIU2 (60 HZ)— OPERATION AND PARTS MANUAL — REV. #0 (01/27/06)
DCA-25SSIU2 (60 HZ)— GENERAL INFORMATION
DCA-25SSIU2 (60 Hz) Series Familiarization
Generator
The MQ Power Model DCA-25SSIU2 (60 Hz) is a 20 kW
generator (Figure 5) 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
Water Temperature Gauge
Water Temperature Alarm Lamp
Oil Pressure Gauge
Oil Pressure Alarm Lamp
Charging Ammeter Gauge
Fuel Level Gauge
Pre-heat Lamp
Panel Light/Panel Light Switch
Ignition Switch
Fuel Filter Water Level Alarm Lamp
Generator Control Panel
The “Generator 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 the Gen. Control Panel)
Automatic Voltage Regulator
Current Transformer
Over-Current Relay
Voltage Rectifier
Starter Relay
Voltage Selector Switch
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 (Optional)
Water Heater (Optional)
Open Delta Excitation System
The DCA-25SSIU2 (60 HZ) 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.