Multiquip operation manual DCA-25SSAI General Information

DCA-25SSAI — GENERAL INFORMATION

DCA-25SSAI FAMILIARIZATION

Generator

The MQ Power Model DCA-25SSAI is a 20 kW generator 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:

zTachometer

zWater Temperature Gauge

zOil Pressure Gauge

zCharging Ammeter Gauge

zFuel level gauge

zEngine Throttle Lever

zPre-Heat Light

zAlarm Lights

zPanel Light

zPanel Light Switch

zStarter Switch

Generator Control Panel

The “Generator Control Panel” is provided with the following:

zOutput Voltage Adjustment Knob

zFrequency Meter (Hz)

zAC Ammeter (Amps)

zAC Voltmeter (Volts)

zAmmeter Change-Over Switch

zVoltmeter Change-Over Switch

Output Terminal Panel

The “Output Terminal Panel” is provided with the following:

zThree 120/240V output receptacles, 50 amp

zTwo 120V input receptacles, 20 amp

z3 Load Circuit Breakers 240V @50 amps

z2 Load GFCI Circuit Breakers 120V@ 20amps

Control Box

The “Control Box” is provided with the following:

zMain Circuit Breaker 60 amps

zOver-Current Relay

Open Delta Excitation System

The DCA-25SSAI 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 leads: A, B, C and D. During light loads, the power to the Automatic Voltage Regulator (AVR) is supplied from the leads parallel connections of B&C. When loads increase, the AVR switches and accepts power from leads A&D. The output of leads A&D increase proportionally with load. This of adding the voltages to each phase provides better voltage response during 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

The DCA-25SSAIis powered by a 4 cycle, water cooled, turbocharged Isuzu QD60(C640) diesel engine.This engine is designed to meet every performance requirement for the generator. Reference Table 5, page 19 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.

The basic controls and indicators for the DCA-25SSAI generator are addressed on the following pages.

Mechanical Governor System

The mechanical governor system control the RPM of the engine. When the engine demands increase or decrease, the mechanical governor system regulates the frequency variation to ±1.5%. The electronic governor option in- creases frequency variation to ±.25%.

PAGE 20 — DCA-25SSAI — PARTS AND OPERATION MANUAL—FINAL COPY (06/30/01)