Product Manual
Table Of Contents
- Table of Contents
- Safety
- General Information
- Specifications
- Unit Serial Number Locations
- Component Locations
- Control Panel
- Power Zone™ Gen Controller
- Controller Features and Functions
- Operator Screens
- Alarm Mute
- Auto/Manual Mode
- Navigation Buttons
- Control Power Switch
- Engine Start
- Engine Stop/Reset
- The Liquid Crystal Display (LCD)
- Operator Screens
- Home Screen
- Engine Screen
- Generator Screen
- Voltage Adjust Screen
- Maintenance Screens
- Generator Summary
- Engine Tab
- Generator Tab
- Alarms Tab
- Input/Output Tab
- Schedule Tab
- Status Tab
- Generator Monitoring
- Engine Monitoring
- Controller Information Displays, Functions and Reset
- Belt Tensioners
- Operation
- Prestart Checklist
- Manual Starting of the Unit
- Auto (Remote) Starting of the Unit
- Derating for Altitude
- Generator Output Connection Lugs
- Fine Voltage Adjustment
- Voltage Selector Switch
- Voltage Regulation
- Customer Convenience Receptacles
- Main Circuit Breaker
- Exhaust Filter Cleaning Operations
- Transfer Switch
- Auto Exercise Timer
- Shutting Down the Unit
- Emergency Stop Switch
- Idle Switch (MMG25I-45I only)
- Towing the Unit
- Lifting the Unit
- Maintenance
- Emissions Information
- Daily Walk Around Inspection
- General Maintenance
- Basic Maintenance Schedule - Isuzu Engine
- Basic Maintenance Schedule - John Deere Engine
- Isuzu Engine Break-In Requirements
- John Deere Engine Break-In Requirements
- Resetting the Maintenance Alarms
- Checking Generator Drive Plate Torque
- Jack Maintenance
- Trailer Wheel Bearings
- Troubleshooting
- Wiring Diagrams
- AC Wiring - MMG25IF4, MMG45IF4
- AC Wiring - MMG35DF4, MMG55DF4
- AC Wiring - 4 Pos. Voltage Selector Switch Option - MMG25IF4, MMG45IF4
- AC Wiring - 4 Pos. Voltage Selector Switch Option - MMG35DF4, MMG55DF4
- AC Wiring Option - Standard Receptacles
- AC Wiring Option - Engine Heater
- AC Wiring Option - Buck Transformer
- AC Wiring Option - PMG
- DC Wiring
- Trailer Lights Wiring
- Wiring Harness - Electric Brake Option
- DC Wiring Option - 12V Battery Charger
- DC Wiring Option - Low Oil Level
- Options & Accessories
Operation
28 MMG25I-35D-45I-55DF4 Operating Manual 36949 B
Figure 3-6. Voltage Selector Switch Connections
VOLTAGE REGULATION
The electronic voltage regulator controls the output of the generator by regulating the current into the exciter field.
The regulator has four screwdriver adjustable potentiometers that may be adjusted for U/F dip, under frequency
protention (U/F), stability, and voltage. The voltage regulator on the unit is adjusted before shipment from the factory.
Contact Generac Mobile Products for additional information before attempting to adjust the voltage regulator.
Note: For units equipped with a Marathon DVR2000E+ digital voltage regulator, please refer to the Marathon operating
manual provided with the unit.
CUSTOMER CONVENIENCE RECEPTACLES
The unit is equipped with five receptacles. The large receptacles are 240/120VAC twist-lock receptacles rated at
50A each. The smaller duplex receptacles are 120VAC rated at 20A each with ground fault circuit interrupt (GFCI)
protection. These receptacles are not routed through the main circuit breaker. Each receptacle has its own circuit
breaker, located above the connection lugs. Each breaker is sized to the maximum rating of the corresponding
receptacle.
L1-L2 = - L1-N = 120V N =
L2-L3 = - L2-N = -
L3-L1 = 240V L3-N = 120V
VOLTAGES AT RECEPTACLES
120/240V 1-PHASE
Switch styles vary by model.
RECEPTACLE L-L L-N
GFCI - 120V
GFCI w/Buck - 120V
Twist-locks 240V 120V
120/
208V
120/
240V
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