Multiquip operation manual DCA-125USJ 50 HZ- General Information

DCA-125USJ (50 HZ)— GENERAL INFORMATION

DCA-125USJ (50 HZ) Series Familiarization

Generator

The MQ Power Model DCA-125USJ (50 HZ)is a 80 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:

zTachometer

zWater Temperature Gauge

zOil Pressure Gauge

zCharging Ammeter Gauge

zFuel Level Gauge

zPre-heat Lamp

zPanel Light/Panel Light Switch

zAuto ON/OFF Engine Controller (MPEC)

zFuel Leak Detected Alarm Lamp

Generator Control Panel

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

zFrequency Meter (Hz)

zAC Ammeter (Amps)

zAC Voltmeter (Volts)

zAmmeter Change-Over Switch

zVoltmeter Change-Over Switch

zVoltage Regulator

z3-Pole, 300 amp Main Circuit Breaker

Control Box

The “Control Box”, located behind the Generator Control Panel, is provided with the following:

zAutomatic Voltage Regulator

zCurrent Transformer

zOver-Current Relay

zVoltage Rectifer

zStarter Relay

zEngine Controller (Computer Controlled)

zVoltage Selector Switch

Output Terminal Panel

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

zThree 100/200V output receptacles (CS-6369), 50A

zThree auxilliary circuit breakers, 50A

zTwo 100V output receptacles (GFCI), 20A

zTwo GFCI circuit breakers, 20A

zFive output terminal lugs (3Ø power)

zBattery Charger (Optional)

zWater Heater (Optional)

Open Delta Excitation System

The DCA-125USJ (50 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.

Engine

The DCA-125USJ(50 HZ)is powered by a 4 cycle, water cooled, direct injection, turbocharged JOHN DEERE Model 6068TF275 Diesel Engine.This engine is designed to meet every performance requirement for the generator. Reference Table 1 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 5) as a guide for selecting proper extension cable size.

PAGE 20 — DCA-125USJ (50 HZ) — OPERATION AND PARTS MANUAL — REV. #0 (03/11/05)