Generac Power Systems MB375 Features

MB375

BI-FUEL DIESEL

Standby Power Rating

375KW 60 Hz

FEATURES

■ INNOVATIVE DESIGN & PROTOTYPE TESTING are key
components of GENERAC'S success in "IMPROVING POWER BY
DESIGN." But it doesn't stop there. Total commitment to component
testing, reliability testing, environmental testing, destruction and life
testing, plus testing to applicable CSA, NEMA, EGSA, and other
standards, allows you to choose GENERAC POWER SYSTEMS
with the confidence that these systems will provide superior
performance.

■ PARALLELING SYSTEM FEATURES

✓ AUTO SYNCHRONIZATION

✓ ISOCHRONOUS LOAD SHARING
✓ REVERSE POWER PROTECTION
✓ MAXIMUM POWER PROTECTION
✓ ELECTRICALLY OPERATED MECHANICAL
HELD CONTACTORS
✓ UL2200 LISTED

■ POWERMANAGER® DIGITAL CONTROL PLATFORM. The
PowerManager® Digital Control Platform (PM-DCP) is a powerful
control system built around a 32 bit industrial microprocessor.
Standard factory programming controls the entire engine generator
system while allowing the PM-DCP, with its onboard PLC, to be
customized to meet any application requirement. The system is
available on single unit gas, diesel or bi-fuel installations as well
as Modular Paralleling Systems (MPS) from 200 kW - 3000 kW.

277/480, 345/600 Volt

Natural Gas With Diesel Pilot Ignition

12.0DTA ENGINE

Turbocharged, Aftercooled

■ REMOTELY PROGRAMMABLE VIA GENLINK communications
software which is provided with each system sold.

■ SOLID STATE DIGITAL VOLTAGE REGULATOR senses all 3
phases, electronically matches surge loads to the torque curve of
the engine.

■ ECONOMICAL POWER. Microprocessor controlled bi-fuel diesel/
natural gas engine provides long, low cost, reliable life.

■ SINGLE SOURCE SERVICE RESPONSE from Generac's dealer
network provides parts and service know-how for the entire unit,
from the engine to the smallest electronic component. You are never
on your own when you own a GENERAC POWER SYSTEM.

■ GENERAC TRANSFER SWITCHE S, SWITCHGEAR AND
ACCESSORIES. Long life and reliability is synonymous with

GENERAC POWER SYSTEMS. One reason for this confidence
is that the GENERAC product line includes its own transfer
systems, accessories, switchgear and controls for total system
compatibility.

■ WEATHER PROTECTIVE SOUND ATTENUATED ENCLOSURE

is available utilizing Generac's advance sound technology.

APPLICATION
& ENGINEERING DATA

GENERATOR SPECIFICATIONS

TYPE ................................................................ Four-pole, revolving field

ROTOR INSULATION ................................................................. Class H

STATOR INSULATION ................................................................ Class H

ADDITIONAL INSULATION ....................................... Antifungal Coating

TOTAL HARMONIC DISTORTION ...................................................<5%

TELEPHONE INTERFERENCE FACTOR (TIF) ................................<50

BEARINGS ............................................................ Prelubed and Sealed

COUPLING ..................................................................Direct Connected

LOAD CAPACITY(Standby Rating) ................................................100%

TEMPERATURE RISE .................................................................125° C

WINDING PITCH ................................................................................2/3

ROTOR ................................................................ Dynamically Balanced

VOLTAGE REGULATOR

Regulation ...................................................Digitally Controlled ± 0.25%

Sensing ....................................................................... Single or 3 Phase

Paralleling Capability ......................................................................... Yes

CONTROL PANEL

Type ....................................... PowerManager Digital Control Platform

DISPLAY

AC Volts ............................................ Line to Line and Line to Neutral

AC Amps ................................................................................Per line

Frequency ........................................................................10-99 Hertz

Oil Pressure ................................................ Digital Touchscreen LCD

Coolant Temperature .................................. Digital Touchscreen LCD

Fuel Level ................................................... Digital Touchscreen LCD

DC Battery Voltage ..................................... Digital Touchscreen LCD

Hour Meter - Run Time Hours .................... Digital Touchscreen LCD

Engine Speed in RPM ................................ Digital Touchscreen LCD

Generator Power kW .................................. Digital Touchscreen LCD

Power Factor ............................................... Digital Touchscreen LCD

Turbo Pressure ........................................... Digital Touchscreen LCD

Gas Pressure.............................................. Digital Touchscreen LCD

Gas Flow (CFM) ......................................... Digital Touchscreen LCD

Air Temperature (Incoming) ........................ Digital Touchscreen LCD

Gas Temperature ........................................ Digital Touchscreen LCD

Charge Air Cooler Valve Position ................ Digital Touchscreen LCD

Not in Auto ................................................................................... LED

Common Alarm ...........................................................................LED

ALARMS

High/Low Generator Voltage ....................... Digital Touchscreen LCD

High/Low Battery Voltage ........................... Digital Touchscreen LCD

High/Low Frequency ................................... Digital Touchscreen LCD

Low Oil Pressure & Prealarm ..................... Digital Touchscreen LCD

High, Low, Critical Low Fuel Level .............. Digital Touchscreen LCD

Overcrank ................................................... Digital Touchscreen LCD

Sensor Failure ............................................ Digital Touchscreen LCD

COMMUNICATION

Serial Communication RS232 and RS485
GenLink Software for PowerManager® Digital Control Platform

ENGINE SPECIFICATIONS

MAKE ......................................................................Generac / Mitsubshi

MODEL ...................................................................................... 12.0DTA

CYLINDERS ............................................................................... 6 in-line

DISPLACEMENT .............................................. 11.945 Liter (729 cu. in.)

BORE .......................................................................................... 5.11 in.

STROKE ...................................................................................... 5.91 in.

COMPRESSION RATIO ................................................................16.5:1

INTAKE AIR ...................................................Turbocharged, Aftercooled

NUMBER OF MAIN BEARINGS ...........................................................7

CONNECTING RODS .....................................................6-Carbon Steel

CYLINDER HEAD ............(6) 1-Cylinder Cast Iron with Overhead Valve

PISTONS ................................................Heat Resistant Aluminum Alloy

CRANKSHAFT .................... Case Hardened, Die Forged, Carbon Steel

Rating definitions - Standby: Applicable for supplying emergency power for the duration of the utility power outage. No overload capability is available for this rating. (All

ratings in accordance with BS5514, ISO3046 and DIN6271).

MB375

ENGINE SPECIFICATIONS Cont.

VALVE TRAIN

LIFTER TYPE .................................................................................. Solid

INTAKE VALVE MATERIAL .............. Stellite Faced Heat Resistant Steel

EXHAUST VALVE MATERIAL ......... Stellite Faced Heat Resistant Steel

HARDENED VALVE SEATS ................................................Replaceable

ENGINE GOVERNOR

❐ ELECTRONIC ...................................................................... Standard

FREQUENCY REGULATION, NO-LOAD TO FULL LOAD .........0.5%

STEADY STATE REGULATION ...............................................+0.25%

LUBRICATION SYSTEM

TYPE OF OIL PUMP .......................................................................Gear

OIL FILTER ............................................. Bypass and Full flow, cartridge

CRANKCASE CAPACITY ................................... 31 Liters (8.2 U.S. gal.)

ENGINE FEATURES

ECONOMICAL POWER Microprocessor controlled bi- fuel diesel engine starts

on diesel fuel and provides power from an air/natural gas mixture ignited by
diesel injection and continuously monitored by the on board control.

LONGER ENGINE LIFE Generac heavy duty bi-fuel diesels provide long and
reliable operating life along with low emissions.

GENERAC GEAR DRIVE Generac's Gear Drive technology drives the engine
at the most economical operating point. The engine runs at 2280 rpm, which is
well below the maximum design speed. The Generac Gear Drive transmission
is constructed with heavy duty helical gears and ball bearings for quiet operation
and long life. It has been in the Generac product line for over 20 years and
several thousand units are installed and in operation today.

EMISSIONS Capable of low particulate and NOx emission levels. Unit is
registered with SCAQMD permitting program (CEP No. 414037)

HOW DOES A BI-FUEL ENGINE WORK?

The diesel engine is equipped with a metering system that feeds natural gas
into the incoming air supply. The standard diesel injection pump is used and
the injector sprays diesel fuel into the cylinder at the correct time. The diesel
fuel ignites and thus ignites the natural gas charge. Total power is derived
from a combination of natural gas and diesel as shown in the chart below.
The ratio of natural gas to diesel fuel is a function of several factors, including
load and intake air temperature. The system is programmed to avoid pre­ignition, but should it occur due to a transient event such as sudden loading
or fuel variation, knock sensors will signal the controller to reduce the flow of
natural gas and the diesel injectors will take over to maintain engine speed
and required power level. The higher thermal efficiency of diesel engines and
the lower cost of natural gas, along with low emission levels, combine to make
the bi-fuel engine a very economical choice.

FUEL PRESSURE - NAT. GAS 2 psi MINIMUM
FUEL CONSUMPTION*

NG ft3/hr. Diesel NG ft3/hr. Diesel
kW @2 psi gal./hr. kw @ 2 psi gal.hr.

225 2355 1.8 325 3402 2.62
275 2880 2.22 375 3358 6.95

Fuel Pressure NG line 2 psi @ full load BTU Content (Min) 920 BTU/ft3 LHV

*Note: Percentages and consumption can vary depending on air temperature and
heat content of fuel

MB375

OPERATING DATA

STANDBY

MB375

GENERATOR OUTPUT VOLTAGE/KW-60Hz kW Rated AMP

277/480V, 3-phase, 0.8 pf 375 564
600V, 3-phase, 0.8 pf 375 450

GENERATOR PARAMETERS
Subtransient Reactance pu. 0.12

Transient Reactance pu. 0.13
Synchronous Reactance pu. 2.98

LOCKED ROTOR kVA %
INSTANTANEOUS DIP 10% 400

20% 750

Note: Available kVA values are based on instantaneous
voltage values and not sustained values. Thus a load that

30% 1210

requires 750 kVA will create a 20% instantaneous voltage dip

35% 1410

from the nominal voltage value.

COOLING

Coolant capacity US gal. 22
Coolant flow/min. 60 Hz - US gal. 70
Heat rejection to coolant BTU/hr. 1,265,000
Radiator air flow 60 Hz - cfm 34,000
Maximum external pressure
drop after radiator "H2O 0.5
Maximum operating air temperature
onto radiator °F 140 *
Maximum operating ambient
temperature °F 120 *

COMBUSTION AIR REQUIREMENTS

Flow at rated power 60 Hz - cfm

EXHAUST

Exhaust flow at rated output 60 Hz - cfm

Max recommended back pressure
"Hg
Exhaust temperature at rated output
(pre-turbo) °F 1350
Exhaust outlet size 5" ANSI Flange

ENGINE

Rated RPM 60 Hz 2280
HP at rated kWe (gross) 60 Hz 555
Piston speed 60 Hz - ft./min. 2249
BMEP 60 Hz psi 264

1257

4237

1.5

SYSTEM DESCRIPTION

Multiple generators are paralleled to a common generator
bus through a unit-mounted switching mechanism to provide
the total power output. The control system consists of the
PowerManager® Digital Control Platform (PM-DCP) along
with a PowerManager® Parallel Controller (PM-PC) for each
375 kW genset. The PowerManager System Controller (PM­SC) is provided in a separate NEMA 1 wall mount enclosure.
It interfaces with the generator controllers to provide start­stop commands based on utility power, proportional load
sharing and provides safe paralleling of each unit to the
common generator bus.

The PowerManager Digital Control System, including
generator controllers, can be locally or remotely viewed
and programmed via Generac GenLink® Communications
software. PowerManager also offers upstream digital
communications via RS485/Modbus to other supervisory
control systems.

TYPICAL OPERATIONAL SEQUENCE

1. A transfer switch detects a utility failure and issues a
start command. The command goes to the PM-SC which
then issues a start command to the Generator Controller
(PM-DC).

2. Each individual generator will start on it's own.

3. The first generator that attains rated frequency and
voltage is connected to the common generator bus via
the switching mechanism.

4. The second generator will synchronize and close into
the bus via its switching mechanism.

5. When all gensets are paralleled to the bus, the PM-SC
will signal the transfer switch or switches to transfer to
the load. There is a maximum of 3 programmed steps
available for connection of multiple transfer switches.

6. If an NFPA requirement for 10 second start exists, the
first unit up will connect to the bus. This causes the
controller in a separate emergency transfer switch to
immediately transfer to the NFPA load.

7. If a single generator fails, load shed contacts are available
to disconnect selected noncritical loads.

8. If load conditions are reduced (night time operation) one
generator can be programmed off-line (optional).

9. When utility supply returns, the PM-SC will issue commands
to transfer loads back to the utility. It then issues commands
to the individual PM-PC to disconnect from the bus. Each
PM-PC will operate its generator for the cool-down period
and then issue a shutdown command.

POWER ADJUSTMENT FOR AMBIENT
CONDITIONS

Temperature °C 25 30 40 50

-2.5% for every 10oF above - °F 77 86 104 122
Rating kW 375 375 375 324
Altitude

-2.5% for every 1000 m. above - m. 1066

-2.5% for every 1000 ft. above - ft. 3500

*Note: Values given are maximum temperatures to which power adjustment

factors can be applied. Consult your Generac representative if
operating conditions exceed these maximums.

STANDARD ENGINE & SAFETY FEATURES

MB375

■ 12 Liter 2300 RPM Diesel Engines

■ 12 Lead 400 kW 60 Hz Generators

■ PM-PC Generator Controllers

■ High Coolant Temperature Automatic Shutdown w/Pre Alarms

■ Low Coolant Level Automatic Shutdown w/Pre Alarms

■ Low Oil Pressure Automatic Shutdown w/Pre Alarms

■ Overspeed Automatic Shutdown (Solid-state)

■ Crank Limiter (Solid-state Programmable)

■ Emergency Stop Button

■ Serial RS232 and RS485 Output

■ Isochronous Governors

■ 1% Digital Voltage Regulator

■ Fuel Shut-Off Solenoid

■ Factory Installed Cool-Flow Radiator

■ 2000 Watt Coolant Heater

■ Rubber-Booted Engine Electrical Connections

■ 35 Amp DC Engine Driven Alternator

■ Air Cleaner (dry type)

■ Dual Oil Filters

■ Vibration Isolators

■ Oil and Antifreeze

■ Critical Mufflers

■ 10 Amp Battery Charger per Engine

■ Stainless Steel Flex Exhaust Connections

■ Flex Fuel Lines

■ 3 Sets of Owners Manuals

■ Mainline Circuit Breaker

■ Two Year Warranty

■ Critical Grade Muffler (2)

■ GenLink® Communications Software

POWERMANAGER® DIGITAL CONTROL PLATFORM

The PowerManager® Paralleling Controller (PM-DC) is a fully programmable, integrated digital generator control console, using a 32-bit industrial
microprocessor to handle all the control, monitoring, input and output genset functions. The open architecture used allows customizing the control
to meet any customer requirement, yet maintaining the simplicity of operating 'as is' with the factory default programming. (see Generac bulletin
#0168840SBY)

OPTIONS

■ OPTIONAL FUEL ACCESSORIES
❍ UL Listed Base Tank

❍ Base Tank Low Fuel Alarm
❍ Secondary Diesel Fuel Filters and Heaters

■ OPTIONAL ELECTRICAL ACCESSORIES
❍ Battery Warmer

❍ Batteries

■ OPTIONAL ALTERNATOR ACCESSORIES
❍ Alternator Heater
❍ Alternator Tropicalization

■ ADDITIONAL OPTIONAL EQUIPMENT

❍ Automatic Transfer Switch
❍ 3 Light Remote Annunciator

■ ADDITIONAL OPTIONAL EQUIPMENT

❍ 21 Light Remote Annunciator
❍ Remote Relay Panel
❍ 2 and 5 Year Extended Warranties

■ POWERMANAGER SYSTEM CONTROLLER
❍ Controls Up To 3 Distinct Transfer Switches

❍ Unlimited Number of Slave Switches
❍ 3 Programmable Load Permissive Relays
❍ NEMA 1 Wall Mount Enclosure
❍ Touch Screen Display Of All Parameters

Distributed by:

Design and specifications subject to change without notice. Dimensions shown are approximate. Contact your Generac dealer for certified drawings. DO NOT USE THESE DIMENSIONS FOR INSTALLATION PURPOSES.

mm [in]

Generac Power Systems, Inc. • S45 W29290 HWY. 59, Waukesha, WI 53189 • generac.com

©2008 Generac Power Systems, Inc. All rights reserved. All specifications are subject to change without notice. Bulletin 0169180SBY/Printed in U.S.A. 11.03, rev: 05.09