DCA-25SSIU2 60 HZ- General Information

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.

PAGE 18 — DCA-25SSIU2 (60 HZ)— OPERATION AND PARTS MANUAL — REV. #0 (01/27/06)