Regal Marathon Generator DVR 2500 User manual

1
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
GENERAL SAFETY INSTRUCTIONS
Before installing, using, or servicing this product, carefully read and fully understand the instructions including all warnings, cautions,
and safety notice statements.To reduce risk of personal injury, death and/or property damage, follow all instructions for proper generator
installation, operation and maintenance.
Although you should read and follow these instructions, they are not intended as a complete list of all details for installations, operation, and
maintenance. If you have any questions concerning any of the procedures, or if you have a safety concern not covered by the instructions, STOP, and
contact the generator manufacturer.
DEFINITION: The word Generator, as used in this publication, includes
only the products of Regal Beloit America, Inc., and does not include the
prime mover or any of the prime mover related systems or accessories.
ELECTRICAL HAZARD
• Failure to connect the voltage regulator in accordance with the
manufacturer’s documentation could result in serious personal injury,
death, and/or property damage.
ELECTRICAL SHOCK HAZARD
• Failure to follow these instructions could result in serious personal
injury, death, and/or property damage.
• Installation and repair of electrical generators and voltage regulators
should be attempted by qualified personnel only. Electrical connections
shall be made by a qualified electrician in accordance with all
local, national, international and/or other applicable codes, rules or
regulations and sound practices.
• Do not touch electrically live parts. Disconnect, lock out and tag prime
mover and input power supplies before installing or servicing voltage
regulator. Use a voltmeter to verify that power is off before contacting
conductors.
• Do not open terminal box or touch unprotected terminals while
the generator shaft is rotating. Shaft rotation produces voltage in
generators even when no excitation is applied. Residual voltage is
present at the generator leads and regulator connections even when
the regulator fuse is removed.
• Ground (earth) the regulator in accordance with local, national,
international and/or other applicable codes, rules or regulations.
EXPLOSION HAZARD
• Beware of arcing when connecting test leads. Arcing could spark an
explosion if exposed to battery gases, fuel vapors or other hazardous
atmospheres. Failure to follow these instructions could result in
serious personal injury, death and/or property damage.
ROTATING PARTS HAZARD
• Keep extremities, hair, jewelry and clothing away from moving parts.
Failure to follow these instructions could result in serious personal
injury, death and/or property damage.
OVERSPEED HAZARD
• Do not exceed the rated speed of the generator. Excessive centrifugal
forces could damage the rotating fields and cause parts to be expelled
at a high rate of speed. Failure to follow these instructions could result
in serious personal injury, death and/or property damage.
DO NOT DISASSEMBLE
• Only qualified personnel who know local, national, international and/or
other applicable codes, rules or regulations and sound practices should
install or repair electric generators and voltage regulators. Failure to
follow these instructions could result in serious personal injury, death
and/or property damage.
MAGNETIC FIELD HAZARD
• Permanent magnet generator (PMG) rotors, when removed from the
stator, expose surrounding personnel and equipment to powerful
magnetic fields which could cause serious health hazards to persons
with pacemakers, hearing aids, or other implanted electronic medical
devices and may impact other electronic devices such as mobile
phones, credit cards, etc.

2
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
TABLE OF CONTENTS
GENERAL SAFETY INSTRUCTIONS 1
GENERAL
Overview 3
Manual Conventions 3
Regulation Modes 3
Features 3
Protection 3
Limiters 3
SPECIFICATIONS
Operating Power 4
Generator Voltage Sensing 4
Generator Current Sensing 4
Contact Inputs 4
Fault Contact Output 4
Field Output 4
AVR1 and 3 Operating Modes 4
FCR Operating Mode 4
VAR Operating Mode 4
PF Operating Mode 4
Parallel Compensation 4
PC Communication Port 5
CAN Communication Port 5
Auxiliary Input 5
Metering 5
Environmental 5
Electromagnetic Compatibility 6
Mechanical Tests 6
Physical 6
Mating Connectors 6
FEATURES AND PROTECTION
Introduction 7
Function Blocks 7
Operating Features 9
Regulation Modes 9
Auxiliary Input 10
Load Sharing 11
Generator Soft Start 11
Protection Functions 12
INSTALLATION
General 18
Mounting 18
Connections 22
Grounding Practices 22
Remote Mounting Guidelines 23
Connection Diagrams 28
Preliminary Set-up 34
HUMAN-MACHINE INTERFACE (HMI)
General 35
Front Panel Display 36
Making Settings Changes 38
Auxiliary Modules
RTD Interface Module 39
DVRPortal™ GRAPHICAL USER INTERFACE (GUI)
Parameter Edit Buttons 40
Header 40
Metering Tab 42
Configuration Tab 40
Operating Modes Sub Panel 41
Set Points Sub Panel 42
Protection Settings Sub Panel 48
Limits 48
Digital I/O 50
Advanced Configuration 51
CAN Bus Configuration Sub Panel 52
Identification Tab 53
MAINTENANCE AND TROUBLESHOOTING
Preventative Maintenance 55
Troubleshooting 55
APPENDIX A
Alarm Codes 62
Fault Codes 62
APPENDIX B
Connector Pin-out Figures and Tables 63
APPENDIX C
Quick Start Programming Guide 65
APPENDIX D
Abbreviations and Acronyms 66

3
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
GENERAL
OVERVIEW
This manual provides details on how to install, operate and maintain
a DVR®2400 or DVR®2500 digital voltage regulator with Marathon®
synchronous generators. A separate publication is available for Controller
Area Network (CAN) communications.
The regulator is a control device that regulates the output voltage of a
brushless, AC generator by controlling the current into the generator
exciter field. Input power to the regulator is derived from a single phase
permanent magnet generator (PMG).
The regulator is supplied in an encapsulated package designed for
behind-the-panel mounting. It is held in place by thread-forming screws
that thread into mounting holes in the face of the regulator. The front
panel display annunciates regulator status and system conditions.
MANUAL CONVENTIONS
This manual describes details of the DVR®2400 and DVR®2500 voltage
regulators. Features that are exclusive to the DVR®2500 regulator are
noted.
REGULATION MODES
Five regulation modes:
• Single phase automatic voltage regulation (AVR1)
• Three phase automatic voltage regulation (AVR3)
• Field current regulation (FCR).
• Reactive power regulation (VAR)
• Power factor regulation (PF)
FEATURES
The DVR® regulator has the following features:
• Preset stability settings based on generator frame size
• Adjustable soft start in AVR1 or AVR3 regulation modes
• Under frequency (Volts/Hertz) regulation
• True RMS Three-phase or single-phase generator voltage sensing
• True RMS current sensing, single phase on the 2400, three phase
on the 2500; (optional CT’s required)
• True RMS power metering, single phase on the 2400, three phase
on the 2500; (optional CT’s required)
• Field current sensing
• Contact inputs for system interface capability
• Contact output for fault indication
• Generator paralleling with reactive droop compensation and reactive
differential compensation
• Front-panel human-machine interface (HMI) for status and
configuration
• MODBUS protocol via USB2.0 for external communication
• DVRPortal™software for configuration and monitoring
• “Power on” LED indicator
• Configurable auxiliary input for metering and control
• Simulated reactive power for droop set-up
• CAN interface with CAN 2.0B J1939 protocol for metering and
control (2500)
• Generator power limiting mode (2500)
• Configurable Parameter Presets selectable through digital inputs
(2500)
• 8 Channel 3-wire PT100 RTD metering (2500) through an external
module
PROTECTION
The DVR® regulator has the following protection features:
• Field Over Excitation Shutdown
• Field Under Excitation Shutdown
• Generator Over Voltage Shutdown
• Generator Under Voltage Shutdown
• Generator Voltage Imbalance Shutdown
• Generator Reverse Power Shutdown
• Loss of Generator Sensing Shutdown
• Instantaneous Field Over Current Shutdown
• Regulator Over Temperature Shutdown
• Generator Parallel Start-Up Shutdown
• Generator Parallel Shutdown Shutdown
• RTD Over Temperature Shutdown (2500)
• Loss of CAN Communication Alarm (2500)
• RTD Pre Alarm Temperature (2500)
• Loss of Aux Input Control Current Alarm (2500)
• Loss of RTD Element -Open Alarm (2500)
• Loss of RTD Element - Short Alarm (2500)
• Genset Battery Low Alarm (2500)
LIMITERS
• Exciter Field Current Limit
• Generator Under Frequency Limit
• Generator Power Limit (2500)

4
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
SPECIFICATIONS
OPERATING POWER
PMG Input:
Type: 1-phase, ungrounded PMG
Range: 180 - 240 Vac, 250 - 300 Hz
Burden: 350 VA
Fuse Type: Time delay 250V - 5.0 A
Terminals: 3, 4
GENERATOR VOLTAGE SENSING
Type: 1-phase/3-phase
Range: 100 to 600 Vac, 50/60 Hz
Burden: <1 VA per phase
Terminals: E1, E2, E3
GENERATOR CURRENT SENSING
Type: 1-phase (Bø) (2400) / 3-phase (2500)
Rating: 5 Aac continuous, 50/60Hz
Input Impedance: <10 mΩ
Terminals: IB1, IB2 for 1-phase (BØ)
IA1, IA2 for 3-phase (AØ) (2500)
IC1, IC2 for 3-phase (CØ) (2500)
BATTERY INPUT (DVR 2500 REGULATOR)
Type: DC
Range: 12 - 24 Vdc
Burden: 10 VA
Terminals: P2-12 (BT+), P2-13 (BT-)
CONTACT INPUTS
Type: Dry Contact
Input PU Voltage: 3.3 Vdc
Source Current: up to 5mA DC
Terminals:
EXCITATION_OFF: P1-6 (EXC), P1-11 (DG)
UP: P1-7 (UP), P1-11 (DG)
DOWN: P1-8 (DN), P1-11 (DG)
DROOP_OFF: P1-9 (DRP), P1-11 (DG)
VAR/PF_OFF: P1-10 (QPF), P1-11 (DG)
DVR®RESET: P2-6 (RST), P2-10 (DG) (2500)
PS0 (Presets): P2-7 (PS0), P2-10 (DG) (2500)
PS1 (Presets): P2-8 (PS1), P2-10 (DG) (2500)
FAULT CONTACT OUTPUT
Type: Form C
Carry Current: 7 Aac/5 Adc continuous
Break Current: 7 Aac / 0.1 Adc
Operating Voltage: 240 Vac / 30 Vdc maximum
Terminals: P1-12 (NO), P1-13 (COM),
P1-14 (NC)
FIELD OUTPUT
Continuous Rating: 100 Vdc, 4.0 Adc
10 Second Forcing Rating
200 Vac Power Input: 190 Vdc, 7.5 Adc
Field Resistance: 15 to 35 Ω
Terminals: F+, F-
AVR1 and AVR3 OPERATING MODES
Range: 100.0 to 630.0 Vac
Voltage Regulation: ±0.25 % over load range at rated power
factor and constant generator frequency.
Temperature Drift: ±0.0125 % per degree C
Soft-Start Range: 2 to 120 seconds
Under frequency (V/Hz)
Under Frequency Slope: 1.00 to 5.00 PU
Under Frequency Knee: 40.0 to 70.0 Hz
FCR OPERATING MODE
Range: 0.000 to 4.000 Adc
Current Regulation: ±1.0% over 15 to 35 Ohms of exciter
resistance
Temperature Drift: ±0.0125% per degree C
Setpoint Integration Time: 0.0 to 15.0 seconds
VAR OPERATING MODE
Range: -100.0% to +100.0% of rated kVAR
VAR Regulation: ±3.0 % of rated kVAR
Temperature Drift: ±0.0125 % per degree C
PF OPERATING MODE
Range: -0.600 to +0.600 PU
PF Regulation: ±0.02 PU
Temperature Drift: ±0.0125 % per degree C
PARALLEL COMPENSATION
Modes: Reactive droop and
reactive differential
(cross-current)
Droop Range: 0.0 to 10.0 %
PC COMMUNICATION PORT
Interface: USB 2.0
Connector: Mini B type (HMI/front panel access)

5
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
CAN COMMUNICATION PORT (2500)
Connector: P2-14 (TR), 16 (CH), 17 (CL),
18 (CG)
Protocol: SAE J1939
Data Rate: 250 kbits/sec
AUXILIARY INPUT
Auxiliary – Control1 Mode
AVR3, AVR1, VAR or PF regulation:
Voltage Range: -3.00 Vdc to +3.00 Vdc
-10.00 Vdc to +10.00 Vdc
(2500)
Set Point Range: -X to +X % shift where
X = 1.0 to 30.0
Burden: 2260 Ω
Terminals: P1-4 (AU+), P1-5 (AU-)
FCR regulation:
Voltage Range: 0.000 Vdc to +4.000 Vdc
Set Point Range: 0.000 Adc to + 4.000 Adc
Increment: 1 mA per 1mV
Burden: 2260 Ω
Terminal: P1-4 (AU+), P1-5 (AU-)
Auxiliary – Control2 Mode (2500):
AVR3, AVR1, VAR or PF regulation
Current Range 4 mA to 20 mA
Set Point Range: -X to +X % shift where X = 1.0 to 30.0
Burden: 250 Ω
Terminals: P1-4 (AU+), P1-5 (AU-)
Jumper: P1-3 (A_L) to P1-4 (AU-)
FCR regulation
Current Range 4 mA to 20 mA
Set Point Range: 0.000 Adc to + 4.000 Adc
Increment: 1 mA per 2.0 uA
Burden: 250 Ω
Terminal: P1-4 (AU+), P1-5 (AU-)
Jumper: P1-3 (A_L) to P1-4 (AU-)
Dynamic Under-Frequency (UF) Slope Modifier
(AVR1 and AVR3 modes) (2500)
Voltage Range: 0.00 Vdc to +5.00 Vdc
UF Slope Range: 0.0 to 5.0
Increment: 0.8 PU slope per 1.00 V
Burden: 2260 Ω
Terminals: P1-4 (AU+), P1-5 (AU-)
METERING
Accuracy of all metering values assumes 25° C, 50/60 Hz and less than
20 % THD.
Regulator-side Metering
Generator Voltage
Range: 10 Vac to 600 Vac
Resolution: 0.1V
Accuracy: 0.5 %
Generator Current
Range: 0.1 to 5.000 Aac (5 Aac CTs)
Accuracy: 0.5 %
Power (Apparent, Real and Reactive)
Range: 0 to 5200 VA and W
0 to 4160 VAR leading/lagging
Accuracy: 3.0 %
Power Factor
Range: 0.6 to 1.0 leading/lagging
Accuracy: 0.02
Frequency
Range: 40 to 75 Hz
Accuracy: 0.2 Hz
Field Current
Range: 0 to 8.0 Adc
Accuracy: 0.5 %
Generator-side (Scaled) Metering
Generator Voltage
Range: 10 V to 15 kV
Accuracy: 0.5 %
Generator Current
Range: 0.1 to 5,000 Aac (5 Aac CTs)
Accuracy: 0.5 %
Power (Apparent, Real and Reactive)
Range: 0 to 10 MVA and MW
0 to 8 MVAR leading/lagging
Accuracy: 3.0 %

6
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
ENVIRONMENTAL
Operating Temperature:
-40°C to +70°C (-40°F to +158°F)
Storage Temperature:
-40°C to +85°C (-40°F to +185°F)
Relative Humidity: < 95 %, non-condensing
Ingress Protection: IP52 (Front, mounted)
IP10 (rear with cover)
ENVIRONMENTAL TESTS
Humidity: Tested per MIL-STD-705B,
Method 711-D in vertically mounted
position
Salt Fog: Tested per MIL-STD-810F
Method 509 in vertically mounted position
ELECTROMAGNETIC COMPATIBILITY
Immunity: Meets EN 61000-6-2: 2005 Electromagnetic compatibility
(EMC) – Part 6-2: Generic standards – Immunity for industrial
environments
Emission: Meets EN 61000-6-4: 2007 Electromagnetic compatibility
(EMC) – Part 6-4: Generic standards – Emission standard for
industrial environments
Electromagnetic Compatibility Tests
Immunity
Electrostatic Discharge (ESD): IEC 61000-4-2
Radiated RF: IEC 61000-4-3
Electrical FastTransient (EFT) / Burst: IEC 61000-4-4
Conducted RF: IEC 61000-4-6
Power Frequency and Magnetic Field: IEC 61000-4-8
Emission
Radiated RF: EN 61000-6-4: 2007, 30 MHz to 1000 MHz
SAE J1113-11:2007 (2500) (BT+ & BT- Terminals)
Immunity to conducted transients on power leads.
Pulse 1c, 2a, 2b, 3A, 3B, 4 and 5a
MECHANICAL TESTS
Shock: 20 Gs in 3 perpendicular planes
Vibration: 2.5 Gs at 5 to 26 Hz
0.050” double amplitude (27 to 52 Hz)
7 Gs at 53 to 500 Hz
PHYSICAL
Weight: 3.5 lb. (1590 g)
MATING CONNECTORS
H1:
Mating Plug Housing: P1, Phoenix®* Contact 1873320 or equivalent
H2:
Mating Plug Housing: P2, Phoenix* Contact 1707942 or equivalent
USB:
Mating Cable: Molex®* Connector 88732-
8900 or equivalent
Maximum Length: 3 meters
*The following are believed to be the trademarks and/or trade names of their respective owners and are not owned or controlled by Regal Beloit Corporation. Molex: Molex, LLC; Phoenix: Phoenix Contact GmbH & Co.

7
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
FEATURES AND PROTECTION
INTRODUCTION
This section describes how the regulator functions and explains its operating features. Regulator functions are illustrated in the block diagram of Figure 4-1.
Before proceeding forward, carefully read and fully understand the warnings, cautions, & safety notice statements in this manual. Failure to do so could
cause severe injury, death, and/or equipment damage.
DVR® REGULATOR FUNCTION BLOCKS
The following paragraphs describe each of the function blocks, inputs and
outputs. Refer to Figure 4-1.
Generator Voltage
Generator voltage is measured at terminals E1 (A-phase), E2 (B-phase),
and E3 (C-phase), for ABC rotation, or E1 (C-phase), E2 (B-phase), and
E3 (A-phase) for CBA rotation. Nominal voltages of up to 600Vac may be
sensed at these terminals. Voltage applied to these inputs is scaled, condi-
tioned and applied to the controller.
Line Currents
Generator line currents (IA, IB, IC) are measured via CTs at connectors
P1 and P2. Current up to 5 Arms may be monitored at these terminals.
These currents are scaled, conditioned and applied to the controller. Refer
to Section - Specifications, for connector pin assignments.
Field Current
Current through the exciter field winding is measured at terminal F+. Field
current is scaled, conditioned and applied to the input of the controller.
Contact Input Circuits
Nine contact input circuits powered from an internal 3.3 Vdc supply pro-
vide input control from user-supplied contacts: UP, DOWN, DROOP_OFF,
EXCITATION_OFF, VAR/PF_OFF, *PS0, *PS1, *DVR_RESET and *VM
(*2500 only)
UP
Closing the UP contact across terminals P1-7 (UP) and P1-11 (DG) causes
the active operating set point to increase.
DOWN
Closing the DOWN contact across terminals P1-8 (DN) and P1-11 (DG)
causes the active operating set point to decrease.
Keeping either contact closed will continue to increase (UP) or decrease
(DOWN) the operating set point until a limit is reached. The limit is de-
termined by the Maximum External Contact Adjust field of DVRPortal™
software. The effect generated by the contacts is displayed in DVRPortal™
software on the Set Points Tab as the value “Contact Offset.”
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Figure 4-1. Simplified Block Design

8
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
Note:
1. The regulator incorporates an adjustable ramp rate for UP/DOWN con-
tacts. This value can be used to adjust ramp rate at which the setpoint
changes when a UP or DOWN contact is closed.This can be adjusted from
0.1 %/sec to 15.0 %/Sec.
2. The regulator incorporates a RETAIN/ RESET feature for external contact
adjust (UP and DOWN) which allows the regulator to either save (RETAIN)
the offset caused by UP or DOWN contact or forget (RESET) the offset
after power cycle.This feature is only enabled in AVR1/AVR3 modes. Refer
to Section 8 - Graphical User Interface, Digital I/O.
3. In FCR mode, UP/DOWN contact can be used to adjust the field current
between 0 and 4.000 Adc. Maximum external contact adjust setting is not
applicable in FCR mode.
Note: Saving the offset will happen once the UP/DOWN contact change is
detected and the the regulator is in AVR1/AVR3 mode.
DROOP_OFF
This function enables reactive load sharing between generators operating
in parallel. Closing the DROOP_OFF contact across terminals P1-9 (DRP)
and P1-11 (DG) disables voltage droop. Opening the contact enables volt-
age droop. Reactivate load sharing is enabled in AVR1, AVR3, PF and VAR
regulation modes through this contact. Ensure that QPF contact sets the
VAR/PF regulation to disable.
EXCITATION_OFF
This contact input disables field excitation without removing power to the
regulator. Closing the EXCITATION_OFF contact across terminals P1-6
(EXC) and P1-11 (DG) disables field excitation. Opening the contact enables
field excitation with a soft start and clears any alarms or faults.
VAR/PF_OFF
Caution: Operation in VAR or PF modes should only be enabled when
generator is paralleled with utility (infinite bus).
This function enables VAR or PF regulation when the generator is paral-
leled to utility. Opening the VAR/PF_OFF contact across terminals P1-10
(QPF) and P1-11 (DG) enables VAR or PF control. Closing the contact dis-
ables VAR or PF regulation and defaults to AVR3 regulation.
Note: DROOP OFF, EXCITATION OFF and VAR/PF OFF polarity can be
configured using DVRPortal™ software. By default, these are set to active
low. Polarities of these contacts can be set only in Preset 1 in case of the
2500. Refer to Section - Graphical User Interface, Digital I/O.
PS0 & PS1:
The DVR®2500 voltage regulator provides the ability for the user to select
one of the four available configurations in the regulator. This is achieved
by changing the contact inputs P2-7 (PS0) and P2-8 (PS1) with respect to
P2-10 (DG).
PS1 PS0 Preset
Open Open Preset1
Open Closed Preset2
Closed Open Preset3
Closed Closed Preset4
Note: Changes will only take effect when in standby mode.
DVR_RESET:
The DVR®2500 voltage regulator provides the ability for user to reset the
regulator without requiring a power cycle by toggling the RESET contact
across terminals P2-6 (RST) and P2-10 (DG).
Communication Port (USB 2.0)
The communication port provides an interface for user programming the
regulator through DVRPortal™ software. The connection is made to the
female USB mini B type connector with a user-supplied, standard USB 2.0
A to mini B type USB cable.
Note:
A. The DVR®2500 voltage regulator can be programmed through the
USB connection without additional power provided by an AC supply or
a battery (2500).
Note: Power ON LED or HMI will not be illuminated
B. USB port should be able to provide 400mAdc current while powering
only through the USB.
C. In case of using USB extender/booster cable, the regulator
needs to be powered either through AC power or battery (2500).
Recommended USB 2.0 booster cable GUE2118 or similar.
D. In order for the regulator to communicate properly via USB, proper
USB drivers need to be installed. Driver is typically installed during
DVRPortal™ software installation. This can be downloaded from the
following link http://www.ftdichip.com/Drivers/VCP.htm for FT232
chipset.
E. Use of USB hubs is not recommended for communication purposes.

9
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
CAN Port (2500)
The CAN port provides an isolated interface for communication and control
of the regulator. This permits the integration of the regulator as a node on
a CAN network. The connection is made to the P2-14 (TR), 16 (CH), 17(CL)
18 (CG) terminals. The CAN communication is powered from an on-board
isolated supply.
Note: Jumpering terminals CL and TR will provide an internal terminating
resistor of 120 ohms.
Controller
The controller portion of the regulator includes the microprocessor and
performs measurement, computation, control and communication func-
tions.
Power Input Stage
Input power is applied to terminals 3 and 4 from a PMG. It is rectified and
filtered before being applied to the power amplifier and the power supply.
Power Supply
The internal switch-mode power supply is fed from the power input stage
and supplies power at the required DC voltage levels to the internal circuit-
ry of the regulator.
Note: Sudden loss of excitation power could lead to the 2500 RESET even
though battery voltage is present.
Power Amplifier Stage
The power amplifier is fed from the power input stage and supplies a con-
trolled amount of power to the exciter field via terminals F+ and F-.
HMI Interface
A four-character light-emitting-diode (LED) display indicates various operat-
ing modes, protective functions, and adjustments. Section - Human-Ma-
chine Interface provides more information about the front panel display.
Changes to settings can be made at the front panel using the four buttons:
- SELECT, UP, DOWN and ENTER
Refer to Section - Human-Machine Interface for more information about
the front panel switches.
- RTD Module (2500):
An eight (8) three-wire RTD interface to the 2500 can be provided
through the RTD module. This module is interfaced to the J2 connector
on the regulator via a DB25 cable. Refer to Section - Auxiliary Modules
for more information about RTD protection configuration.
Fault Output Contact
A fault output contact is provided through terminals P1-12, P1-13 and -P1-
14. This Form-C relay closes contacts between P1-12 and P1-13 or opens
contacts between P1-13 and P1-14 in the event of a protective shutdown.
DVR®REGULATOR OPERATING FEATURES
REGULATION MODES
The 2400 and 2500 provide five modes of regulation selectable through
the HMI or through the DVRPortal™ software.
Automatic Voltage Regulation Modes (AVR)
There are two automatic voltage regulation modes. AVR1 should be se-
lected if the regulator is connected for single phase voltage sensing and
AVR3 should be selected if the regulator is connected for three phase volt-
age sensing. In either mode, the regulator regulates the generator RMS
output voltage. Regulation is accomplished by sensing generator output
voltage and adjusting dc output excitation current to maintain voltage at
the regulation set point. The regulation set point is adjusted via the UP
and DOWN contact inputs, the auxiliary input (when enabled), the HMI
or DVRPortal™ software. The Droop and Under Frequency functions may
influence the regulation set point.
Field Current Regulation Mode (FCR)
In FCR mode, the regulator maintains DC excitation current at a command-
ed level. The regulation set point is adjusted via the UP and DOWN contact
inputs, the auxiliary input (when enabled), the HMI or the portal.
Reactive Power Regulation Mode (VAR)
In Reactive Power Regulation (VAR) mode, the regulator maintains the
generator’s reactive power at a commanded level.The regulation set point
is adjusted via the UP and DOWN contact inputs, the auxiliary input (when
enabled), the HMI or the portal. This mode can only be entered by select-
ing “VAR” as the regulation mode and opening the VAR/PF_OFF contact
input.
Power Factor Regulation Mode (PF)
In Power Factor Regulation (PF) mode, the regulator maintains the gener-
ator’s power factor at a commanded level. The regulation set point is ad-
justed via the UP and DOWN contact inputs, the auxiliary input (when en-
abled), the HMI or the portal. This mode can only be entered by selecting
“PF” as the regulation mode and opening the VAR/PF_OFF contact input.

10
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
AUXILIARY INPUT
Note: If the DC voltage is removed from the auxiliary input, the op-
erating set point will no longer be modified and the regulator will
regulate to the programmed regulation set point.
Functionality of the auxiliary input is dependent on the configuration of
the modes described below. The auxiliary input can be set to Off, Con-
trol1, Control2 or Dynamic Slope mode through the HMI or the DVRPortal™
software. The effect of the auxiliary input on the set point is displayed in
DVRPortal™ software.
Auxiliary – Off
In this mode, any signal applied to the auxiliary input will be displayed
in DVRPortal™ software, but will have no effect on the set point of the
regulator.
Auxiliary – Control1
This mode allows modification of the regulation set point by the application
of a positive or negative DC voltage across terminals P1-4 (AU+) and P1-5
(AU-). A voltage up to +/- 3 Vdc may be applied at this input.
Note:The 2500 provides selectable ranges of +/-5 Vdc or +/-10 Vdc through
DVRPortal™ software and configurable range up to 30%.These ranges are
selectable only for AVR1, AVR3, VAR of PF regulation modes.
When in AVR3 or AVR1:
The application of a +/- 3.000 Vdc signal corresponds to a percentage off-
set of up to +/- 30.0% to the set point. If the voltage range is selected as
+/-10V in the 2500, the application of a +/-10.000 signal will correspond to
a percentage offset of up to +/-30% to the set point.
Example: A programmed regulation set point of 480 Vrms, with an
auxiliary input scale factor of 30% and an auxiliary input of -1 Vdc will re-
sult in a -10% (–48 Vrms) offset to the set point. Therefore, the regulator
will regulate to a reference voltage of 432 Vrms.
When in FCR:
The application of a -/+ 4.000 Vdc signal corresponds to a 0.000 to +4.000
Adc field current set point. The auxiliary input scale factor is disabled in
FCR mode.
Note: Any field current reference less than 0.000 Adc will become 0.000
Adc.
Example: The application of a 1.25 Vdc signal will result in a field current
of 1.250 Adc.
When in VAR:
The application of a +/- 3.000 Vdc signal corresponds to a percentage off-
set of up to +/- 30.0% to the VAR set point.
Example: A programmed VAR regulation set point of 50.0% with an
auxiliary input scale factor of 30.0% and an auxiliary input of -1 Vdc will
result in a –10.0% offset to the VAR set point. Therefore, the regulator
will regulate to 40.0% of rated VAR’s.
When in PF:
The application of a +/- 3.000 Vdc signal corresponds to an offset of up to
+/- 0.300 PU to the power factor set point.
Example: A programmed power factor regulation set point of 0.950
(lagging power factor) with an auxiliary input scale factor of 30.0% and
an auxiliary input of -1 Vdc will result in a –0.100 offset to the power
factor set point. Therefore, the regulator will regulate to a power factor
of -0.950. In this case, the power factor has gone from a lagging to a
leading state.
Auxiliary – Control2 (DVR®2500 regulator only)
This mode allows modification of the regulation set point by the application
of a 4 mA to 20 mA current control signal at terminals P1-4 (AU+) and P1-5
(AU-). This mode requires the placement of a jumper across terminals P1-3
(A_L) and P1-4 (AU+).
Note: If loss of auxiliary control current alarm is enabled and if the sensed
current is below the alarm threshold the auxiliary bias will be set to zero. If
the alarm is disabled, the bias will saturate to lower end of the user chose
bias limit.
When in AVR3 or AVR1:
The application of a 4 mA to 20 mA input corresponds to a percentage
offset of up to +/- 30.0% to the voltage set point.
Example: A programmed regulation set point of 480 Vrms, with an
auxiliary input scale factor of 30% and an auxiliary input of 9.33 mA will
result in a –48 Vrms offset to the set point. Therefore, the regulator will
regulate to a reference voltage of 432 Vrms.
When in FCR:
The application of a 4 mA to 20 mA signal corresponds to a 0.000 to
+4.000 Adc field current set point. The auxiliary input scale factor is dis-
abled in FCR mode.
Note: Any field current reference less than 0.000 Adc will become 0.000
Adc.

11
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
Example: A field current set point of 1.000 Adc with the application of a
11.00 mA signal will result in a total field current of 0.500 Adc.
When in VAR:
The application of a 4 mA to 20 mA signal corresponds to a percentage
offset of up to +/- 30.0% to the VAR set point.
Example: A programmed VAR regulation set point of 50.0% with an
auxiliary input scale factor of 30.0% and an auxiliary input of 9.33 mA
will result in a –10.0% offset to the VAR set point. Therefore, the regula-
tor will regulate to 40.0% of rated VARs.
When in PF:
In the PF regulation mode, the application of a 4 mA to 20 mA signal cor-
responds to an offset of up to +/- 0.300 PU to the power factor set point.
Example: A programmed power factor regulation set point of 0.950
(lagging power factor) with an auxiliary input scale factor of 30.0% and an
auxiliary input of 9.33 mA will result in a –0.100 offset to the power factor
set point. Therefore, the regulator will regulate to a power factor of -0.950.
In this case, the power factor has gone from a lagging to a leading state.
Auxiliary - Dynamic Slope (DVR®2500 regulator only):
The 2500 regulator provides a mode in which an auxiliary voltage of 0 to
+5V supplied between terminals P1-4 (AU+) and P1-5 (AU-) can be used
to influence the under-frequency slope multiplier from 1.0 - 5.0 or 5.0 -
1.0 based on dynamic slope polarity while in AVR1 and AVR3 regulation
modes. See Figure 4-2.
Figure 4-2. Dynamic Slope Multiplier
LOAD SHARING
Note: The machine nameplate rated power, rated power factor, CT
Ratio and PT Ratio (if applicable) MUST be entered to calculate the
proper rated reactive power for the droop reference.
The regulator provides a reactive droop compensation feature to enable
reactive load sharing during parallel generator operation. When this feature
is enabled, the regulator calculates the reactive portion of the generator
load using the sensed generator output voltage and current quantities and
then modifies the voltage regulation set point accordingly.
A unity power factor generator load results in almost no change in gen-
erator output voltage. A lagging power factor generator load (inductive)
results in a reduction of generator output voltage. A leading power factor
generator load (capacitive) results in an increase of generator output volt-
age.
Droop is adjustable up to 10.0% with rated reactive power (VAR’s) and
rated power factor. The effect of droop on the set point is displayed in the
DVRPortal™ software. The droop feature is enabled and disabled through
the DROOP_OFF contact input circuit (terminals P1-9 (DRP) and P1-11
(GND). When single-phase current sensing is used, the droop function re-
sponds to phase B current. When three-phase current sensing is used,
the droop function responds to the average phase current. Reactive load
sharing in AVR1, AVR3, VAR and PF modes.
GENERATOR SOFT START
The regulator incorporates an adjustable soft start feature that controls the
time for generator voltage to ramp to the regulation set point. This feature
is enabled in AVR3 and AVR1 regulation modes. The ramp rate is adjust-
able from 2 to 120 seconds (default of 3 seconds).This adjustment is made
through the portal and cannot be made through the HMI. The Generator
Under Frequency feature is also active during Generator Soft Start and
takes priority in control of the generator voltage.

12
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
PROTECTION FUNCTIONS
CONFIGURABLE SHUTDOWNS
Protection
Feature
Customer
Disable/
Enable
Alarm Variable
Alarm
Threshold
Range
Alarm Reset
Hysteresis
Threshold
Units Basis Timer
Range
Timer
Units
Alarm
Code
Fault
Code
Field Over-
excitation No Exciter Field
Current 0.50 to 5.00 0.5 - 5.0 A N/A 1.0 to 15.0 S A008 F008
Field Under-
excitation Ye s Total Reactive
Power
-100.0 to
-5.0 0.0 - 5.0 %
Rated
Reactive Power
(kVAR)
1.0 to 15.0 S A002 F002
Generator
Over-voltage No AVR1: Generator
Line-line Voltage
AVR3: Average
of Generator
Line-line Voltage
5.0 to 20.0 0.0 - 5.0 % Voltage
Set-point 0.1 to 15.0 S A013 F013
Generator
Under-
voltage
Ye s 5.0 to 50.0 0.0 - 5.0 % Voltage
Set-point 1.0 to 15.0 S A012 F012
Generator
Voltage
Imbalance
No
AVR1: Not
Enabled
AVR3: Difference
of Max. & Min.
Line-line voltage
20.0 to 35.0 0.0 - 5.0 %
AVR3: Average
of Three
Generator
Line-line
Voltages
1.0 to 15.0 S A016 F016
Generator
Loss of
Sensing
AVR1
Ye s Ye s 10.0 - 40.0 N/A % Voltage Set
Point
2X LOS
AVR3 timer mS N/A F011
Generator
Loss of
Sensing
AVR3
Ye s Ye s 20.0 - 35.0 N/A % Voltage Set
Point 10 - 1000 mS N/A F011
Generator
Reverse
Power
Ye s Total Real Power -5.0 to
-100.0 5.0 % Rated Power
(kW) 1.0 to 15.0 S A014 F014
RTD Over
Temperature
(1-8)
Ye s RTD Temperature 0 to 260 (0- 100) % Deg C N/A 0 to 3600 S A005 F005
Table 4-2
Before proceeding forward, carefully read and fully understand the warnings, cautions, & safety notice statements in this manual. Failure to do so could
cause severe injury, death, and/or equipment damage.
Incorrect setting for the protective functions can harm the DVR regulator and the alternator and can cause severe injury, death, and/or equipment damage.

13
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
NON CONFIGURABLE SHUTDOWNS
Protection Feature
Customer
Disable/
Enable
Shutdown
Variable Shutdown Threshold Threshold
Units
Alarm
Code
Fault
Code
Instantaneous Field Over-current No Regulator Main
Switch Current 11 A N/A F009
Regulator Over-temperature No DSP Core
Temperature 150 Deg C A007 F007
Generator Parallel Start-up No VAR/PF_OFF
contact input
VAR/PF_OFF Inactive in STANDBY state
*AND* VAR/PF Regulation mode N/A N/A F004
Generator Parallel Shutdown Ye s EXC_OFF
contact input
VAR/PF_OFF Inactive *AND”
EXC_OFF active in RUN.P state N/A N/A F003
Table 4-3
CONFIGURABLE ALARMS
Alarm
Customer
Disable/
Enable
Alarm
Variable
Alarm Threshold
Range
Reset
Hysteresis
Threshold
Units
Timer
Range
Timer
Units
Alarm
Code
Genset Battery Low Ye s Battery Voltage 10.5 - 13.0 N/A V N/A N/A A004
RTD Pre Alarm
Temperature (1-8) Ye s RTD temperature 0 to 260 (0-100) % Deg C (0- 3600) S A005
Loss of CAN Ye s
Time period between
incoming CAN messages
No incoming
CAN messages N/A N/A 1.0 to 45.0 S A006
Loss of Aux Input
Control Current Ye s Auxiliary Input Current 0.002 - 0.004 N/A A N/A N/A A 011
Table 4-4
NON-CONFIGURABLE ALARMS
Alarm
Customer
Disable/
Enable
Alarm
Variable
Alarm
Threshold
Threshold
Units
Alarm
Code
Loss of RTD Element - Open Ye s RTD Resistance Greater Than 201.48 Ohm A005
Loss of RTD Element - Short Ye s RTD Resistance Less than 69.87 Ohm A005
Real Time Clock Battery Low Ye s RTC Battery Voltage Less than 2.5 V A003
Table 4-5

14
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
CONFIGURABLE LIMITERS
Limiter Customer
Disable/Enable
Limit
Variable
Limit
Threshold
Limit
Units
Limiter
Code
Exciter Field Current Limit No Exciter Field Current 0.500 - 7.500 A N/A
Power Limit of Generator Voltage Ye s Generator Real Power 5.0 - 115.0 V N/A
Under-frequency Limit of Generator Voltage No Generator Frequency 40.0 - 70.0 V A015
Table 4-6
Note: When limits are active, no event is recorded in the event log.
Configurable Protection Shutdowns
All configurable protection features have a user-defined threshold,
hysteresis and timer value. By default, all these protections are enabled,
but some of the protections can be disabled by using ENABLE/DISABLE.
If the threshold condition for a particular protection feature is met, an
alarm is triggered. The regulator displays an alarm signal on the HMI and in
the DVRPortal™ software. An independent timer starts at the moment the
alarm condition is triggered. The regulator stays in alarm condition unless
the measured value recovers to above or below hysteresis value depend-
ing on the protection function.
If the timer threshold is exceeded before the alarm condition is resolved, a
fault is then triggered and the excitation current to the field is shut down.
A fault signal is displayed on the HMI and in the portal. Refer to Section
- DVR®Protection Functions for details of the timer-based protection fea-
tures in the regulator.
Field Over Excitation Shutdown
The Field Over Excitation protection feature is triggered if the field current
exceeds the threshold. The fault is triggered if the field current doesn’t fall
below the set hysteresis level within the timer period.
Field Under Excitation Shutdown
The Field Under Excitation protection feature is triggered if the absorbed
VAR’s exceeds the threshold. The fault is triggered if the absorbed VAR’s
do not fall below the hysteresis level within the timer period.
Generator Over Voltage Shutdown
The Generator Over Voltage protection feature is triggered if the generator
voltage exceeds the threshold. The fault is triggered if the generator volt-
age does not fall below the hysteresis level within the timer period.
Generator Under Voltage Shutdown
The Generator Under Voltage protection feature is triggered if the gener-
ator voltage drops below the threshold. The fault is triggered if the gener-
ator voltage stays below the hysteresis level for the duration of the timer.
Generator Voltage Imbalance Shutdown
The Generator Voltage Imbalance protection feature is triggered if a voltage
imbalance is detected in AVR3, VAR or PF regulation modes, imbalance
difference between any single phase and the average of the three phases
is more than the threshold is interpreted as a voltage imbalance. The fault
is triggered if the voltage imbalance condition continues and the average
voltage stays below the hysteresis level for the duration of the timer.
In AVR1 and FCR regulation modes, generator voltage imbalance protec-
tion is disabled.
Generator Reverse Power Shutdown
The Generator Reverse Power protection feature is triggered if generator
reverse power exceeds the threshold. The fault is triggered if generator re-
verse power stays above the hysteresis level for the duration of the timer.

15
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
RTD Over Temperature (2500)
The RTD Over Temperature protection alarm is triggered if the measured
RTD temperature exceeds the set threshold on a particular channel. The
fault is triggered if RTD temperature stays above the hysteresis level for
the duration of the timer. These over temperature protections can be en-
abled/disabled using ENABLE/DISABLE found under Thermal Protection
tab in the DVRPortalTM software.
Loss of Generator Sensing Shutdown
The Loss of Generator Sensing protection feature is triggered if the sensed
voltage difference between any single phase and the average of the three
phase is more than the percentage threshold of the voltage setpoint. In
AVR1 this protection is triggered if the voltage difference between line-line
is more than the percentage threshold of the voltage setpoint.
There is no alarm for this condition – the fault and shutdown is triggered
shortly after the condition is met and the timer expires.
Note: In AVR1, AVR3, VAR and PF regulation modes, Loss of Sensing is
not enabled until a soft start is complete.
Non-Configurable Protection Shutdowns
Non-configurable protection features have factory-defined settings for
thresholds and timers, if applicable. Each shutdown feature shown in
Non-Configurable Shutdowns describes the details of the conditions for
the shutdown event to occur. Refer to Section - DVR®Protection Functions
for details of the timer-based protection features in the DVR® regulator.
Instantaneous Field Over Current Shutdown
The Instantaneous Field Over Current protection feature triggers a fault if
generator field current exceeds 11 Adc. There is no alarm for this condition
– the fault and shutdown is triggered shortly after the condition is met.
Regulator Over Temperature Shutdown
The Regulator Over Temperature protection feature is triggered if the
internal regulator temperature exceeds a factory default alarm threshold.
A fault is triggered if the regulator temperature exceeds a factory default
shutdown threshold.
Generator Parallel Start Up Shutdown
The Generator Start Up Shutdown protection feature is triggered if the
generator is started up in either VAR or PF regulation mode with the QPF
contact active.
Generator Parallel Shutdown Shutdown
The Generator Parallel Shutdown protection feature is triggered if exci-
tation is shut off using EXC contact input when the regulator is performing
VAR or PF regulation.
Configurable Limiters
All configurable limiter features have a user-defined threshold value. By
default, most of these are enabled, but can be disabled by using ENABLE/
DISABLE (except UF and Field Current Limit). If the threshold condition
for a particular limiter feature is met, an indicator is triggered in the portal.
Refer Section - DVR®Protection Functions to for details of the limiters.
Generator Under Frequency (UF) Limit
The Generator Under Frequency Limit triggers if the generator frequency
drops below the under frequency knee.The voltage set point is automatical-
ly adjusted by the regulator so that generator voltage follows the selected
V/Hz curve. If generator frequency drops below cut-out frequency, the
regulator will stop providing generator excitation and AC metering.
• For an under frequency knee between 40.0 and 50.0 Hz, the base slope
is 1/50 (0.02) VPU/Hz
• For an under frequency knee between 50.1 and 60.0 Hz, the base slope
is 1/60 (0.0167) VPU/Hz
• For an under frequency knee between 60.1 and 70.0 Hz, the base slope
is 1/70 (0.0143) VPU/Hz
Where VPU = 1.0 at regulator voltage set point. The base slope is modified
by the slope multiplier to achieve a desired voltage roll-off characteristic.
See Figure 4-4 for examples.
To calculate resulting voltage dip:
Vdip = (Base Slope) *(Slope Multiplier) *(Operating Voltage) *(Hz dip be-
low the knee point)
Example: 480V, 59 Hz knee, Slope = 2, 56 Hz output.
(0.0167) *(2) *(480V) *(3Hz) = 48.1V dip or 431.9V
Note: If generator frequency drops below a detectable level and gen-
erator speed is greater than run cut-in speed, a short circuit condition is
assumed and the regulator will force current up to the Field Current Limit
value (see Field Current Limiting).
The V/Hz slope is dependent upon the under frequency knee and the
slope multiplier. The base slope is defined according to the following (see
Figure 4-3).

16
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
Figure 4-3. Volts/Hertz Slopes vs. Knee Frequency
Field Current Limiting
The Field Current Limit protection feature limits the amount of DC current
that flows into the exciter. It is engaged if load conditions require a field
current larger than the limit. Under such conditions, the current is limited
to the Field Current Limit value which can be configured through DVRPor-
tal™ software. The portal displays this alarm condition, no HMI indication.
Power Limiting Alarm
The Power Limit protection feature limits the amount of output power from
the generator by modifying voltage to maintain constant output power
at the limit. The portal displays this alarm condition, no HMI indication.
This limiter can be enabled or disabled in the Protection Settings Tab in
portal under the Limits panel. The limiter dynamics (PID gains) can also be
adjusted in the Operating Modes Tab in portal.
Figure 4-4. Examples of Under Frequency and Slope
Note: Arrows indicate hysteresis of cut-in and cut-out transitions
between IDLE and RUN states.

17
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
Configurable Protection Alarms
Genset Battery Low Alarm
The Genset Battery Low Alarm is triggered if the measured battery voltage
is less than factory defined threshold. The regulator stays in this condition
until the battery voltage recovers above the threshold value. This alarm can
be enabled or disabled using ENABLE/DISABLE under the protection tab
in the DVRPortal™ software.
RTD Pre-Alarm Temperature Alarms
The RTD Pre-AlarmTemperature Alarms are triggered if the measured tem-
perature of the RTD element is greater than the threshold and the set tim-
er expired. The regulator stays in this alarm condition until the measured
temperature is below the set alarm hysteresis level. These Pre-Alarms can
be enabled/ disabled using ENABLE/DISABLE found under Thermal Pro-
tection tab in the portal.
Loss of CAN Communication Alarm
The Loss of CAN Communication protection feature indicates an alarm if
communication traffic between the regulator and any Electronic Control
Unit (ECU) on the CAN bus is lost. The alarm is triggered if the regulator
does not receive a “VR Heartbeat” message within the threshold time.
Refer to the DVR®2500 CAN Bus Interface User Guide for details.
Loss of AUX Input Control Current
The Loss of AUX Input Control Current is triggered if the measured control
current in AUX Control Mode 2 falls below the user set threshold value
mentioned in Configurable Alarms. This alarm can be enabled or disabled
using ENABLE/DISABLE under the protection tab in the portal.
Note: If loss of auxiliary control current alarm is enabled and if the sensed
current is below the alarm threshold, the auxiliary bias will be set to zero.
Non Configurable Protection Alarms
Loss of RTD Element - Open Alarms
The loss of RTD element open alarm is triggered if the measured RTD
element resistance is greater than factory defined threshold.The regulator
latches this alarm and stays in this condition until the measured resistance
is within the measurable range of the regulator after power cycling. These
Loss of RTD Element Alarms can be enabled/disabled using ENABLE/DIS-
ABLE found under Thermal Protection tab in the portal.
Note:
1. If the regulator detects an open circuit RTD, the metering for that chan-
nel would be saturated to 500°C.
2. If RTDs are not connected to the regulator, the metering would read
-200°C for all channels.
3. The regulator detects an open circuit only if either ‘+’ or ‘ -’ terminals
are open. If the “C” terminal is open, the regulator saturates to -200°C.
Loss of RTD Element - Short Alarms:
The loss of RTD element short alarm is triggered if the measured RTD
element resistance is less than factory defined threshold. The regulator
latches this alarm and stays in this condition until the measured resis-
tance is within the measurable range of the regulator after power cycling.
These Loss of RTD Element Alarms can be enabled/disabled using
ENABLE/DISABLE found under Thermal Protection tab in the portal.
Note:
1. If the regulator detects a short circuit RTD, the metering for that channel
would be saturated to -200°C.
2.The regulator detects a short circuit only if ‘+’ and ‘ -’ terminals are short.
Real Time Clock Battery Low Alarm:
The Real Time Clock (RTC) Battery Low Alarm is triggered if the measured
RTC battery voltage is less than factory defined threshold. The regulator
stays in this condition until the battery voltage recovers above the thresh-
old value. This alarm can be enabled or disabled using ENABLE/DISABLE
under the protection tab in the portal.
Note: The battery alarm is cleared once the measured battery voltage is
above factory set threshold on power-up.

18
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
INSTALLATION
ELECTRICAL HAZARD
• Failure to connect the voltage regulator in accordance with the
manufacturer’s documentation could result in serious personal injury,
death, and/or property damage.
ELECTRICAL SHOCK HAZARD
• Failure to follow these instructions could result in serious personal
injury, death, and/or property damage.
• Installation and repair of electrical generators and voltage regulators
should be attempted by qualified personnel only. Electrical connections
shall be made by a qualified electrician in accordance with all
local, national, international and/or other applicable codes, rules or
regulations and sound practices.
• Do not touch electrically live parts. Disconnect, lock out and tag prime
mover and input power supplies before installing or servicing voltage
regulator. Use a voltmeter to verify that power is off before contacting
conductors.
• Do not open terminal box or touch unprotected terminals while
the generator shaft is rotating. Shaft rotation produces voltage in
generators even when no excitation is applied. Residual voltage is
present at the generator leads and regulator connections even when
the regulator fuse is removed.
• Ground (earth) the regulator in accordance with local, national,
international and/or other applicable codes, rules or regulations.
EXPLOSION HAZARD
• Beware of arcing when connecting test leads. Arcing could spark an
explosion if exposed to battery gases, fuel vapors or other hazardous
atmospheres. Failure to follow these instructions could result in
serious personal injury, death and/or property damage.
ROTATING PARTS HAZARD
• Keep extremities, hair, jewelry and clothing away from moving parts.
Failure to follow these instructions could result in serious personal
injury, death and/or property damage.
OVERSPEED HAZARD
• Do not exceed the rated speed of the generator. Excessive centrifugal
forces could damage the rotating fields and cause parts to be expelled
at a high rate of speed. Failure to follow these instructions could result
in serious personal injury, death and/or property damage.
DO NOT DISASSEMBLE
• Only qualified personnel who know local, national, international and/or
other applicable codes, rules or regulations and sound practices should
install or repair electric generators and voltage regulators. Failure to
follow these instructions could result in serious personal injury, death
and/or property damage.
MAGNETIC FIELD HAZARD
• Permanent magnet generator (PMG) rotors, when removed from the
stator, expose surrounding personnel and equipment to powerful
magnetic fields which could cause serious health hazards to persons
with pacemakers, hearing aids, or other implanted electronic medical
devices and may impact other electronic devices such as mobile
phones, credit cards, etc.
GENERAL
Generally, the DVR® voltage regulator is supplied mounted to the conduit
box of the generator. The purpose of this section is to provide mount-
ing information to customers replacing an existing regulator with the
2400/2500 or those wishing to mount the regulator remotely.
If the unit is not installed immediately, store it in the original shipping
package in an environment free of moisture and dust.
MOUNTING
The regulator is normally located in the generator conduit box. It is de-
signed for behind-the-panel mounting and requires a cutout for front panel
viewing and access. Mounting hardware consists of six customer-sup-
plied, #12 thread-forming screws that pass through holes in the conduit
box and thread into the mounting holes in the regulator. The recommend-
ed torque range for the steel mounting screws is 36 to 40 inch-pounds (4.1
to 4.5 Newton-meters). Refer to Section - Specifications, for environmen-
tal requirements.
The 2400/2500 front panel and uncovered rear dimensions are shown in
Figure 5-1.
The 2400/2500 rear panel with cover dimensions are shown in Figure 5-2.
Cutout and drilling dimensions are shown in Figure 5-3.

19
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
Figure 5-1. The 2500 front dimensions without cover. Valid for 2400 & 2500 versions.

20
F O R M
DVR®2400 and DVR®2500 Digital Voltage Regulator
Installation, Operation and Maintenance Manual
SB0056E
Revised
November 2018
Regal Beloit America, Inc.
100 East Randolph Street
Wausau, WI 54402-8003
www.regalbeloit.com/Brands/
Marathon-Generators
Figure 5-2. The 2500 rear dimensions with cover. Valid for 2400 & 2500 versions.